We are updating our HBO policies and I would appreciate your opinion on how to decompress the 2 following situations...

Thank you for your question. The UHMS HBO2 safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

The Safety Committee interprets your question to be about monoplace chambers and, since we do not know the manufacturer, the response will be generic and may not apply to your chamber. The chamber manufacturer will have recommendations for emergency operation of the chamber. Check the operator’s manual and call the manufacturer. You may wish to review the NFPA 99 Health Care Facilities Code, 2018 edition, annex material B.14.3 Suggested Procedures for Hyperbaric Chamber Operator to Follow in the Event of Fire in a Class B chamber, as this is a valuable resource.

Timed emergency drills as required by NFPA 99 2018, edition, section 14.3.1.4. These rules and regulations will provide your team valuable information for development of your emergency procedures.

1. In the event of a fire, we suggest that all chambers in the department be decompressed as soon as possible. This action should not delay the response to the chamber with the fire, and the priority to relocate patients and staff to a safe place.

2. Without knowing the manufacturer of your chamber it is hard to be specific. In general, if gas supply is lost, many class B chambers are designed to decompress. You may have enough driving pressure in the lines to emergently decompress the chamber. We would suggest trying operation of the chamber during an emergency drill by shutting off the main supply to an un-manned chamber and develop your management plan based on the results of the drill.

Respectfully,

The UHMS Safety Committee

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

What is the accepted time to establish a clinically relevant dose of O2 in a class B chamber when initially compressed with near 100% O2 (USP grade A medical O2)?

Thank you for your question. The UHMS HBO2 safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

This is a great question and one that we should all be asking. The UHMS safety committee is not in a position to be able to state what a clinically relevant dose of HBO₂ would be. We can try to answer how long a typical class B chamber would take to achieve near 100% oxygen.

The definition of Hyperbaric Oxygen Therapy (HBO₂), in the UHMS Hyperbaric Therapy Indications 13th edition, is “An intervention where a person breathes near 100% (USP medical oxygen) while inside a hyperbaric chamber that is pressurized to a greater than sea level pressure. Current information indicates that the pressure be at least 1.4 atmospheres absolute (ATA). Common treatment pressures range between 2.0 and 3.0 ATA with typical treatment times of 90 -120 minutes of oxygen breathing at pressure.  USP medical oxygen is at least 99% oxygen. The time required to achieve near 100% oxygen in the chamber is dependent in part, on the size of the chamber, gas supply to the chamber, ventilation rate and pressure in the chamber. The time frame to achieve near 100% O2 in the class B chamber can range between 10 to greater than 30 minutes, depending on the variables involved. This subject has not been adequately studied.

You should also contact your chamber manufacturer to see what their response to this question is. We would like to see more chambers available that provide information at the control panel for O2% in the chamber and ac

Thank you for your question. The UHMS HBO2 safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

This is a great question and one that we should all be asking. Clinically relevant dosing should be determined by the hyperbaric medical director of your facility. The UHMS has published an “Indications” book that is a relevant resource in this respect.  As we are aware that the nature of your question may lean towards the technical side, we will discuss how long a typical class B chamber would take to achieve near 100% oxygen.

The definition of Hyperbaric Oxygen Therapy (HBO₂), in the UHMS Hyperbaric Therapy Indications 13^th edition, is “An intervention where a person breathes near 100% (USP medical oxygen) while inside a hyperbaric chamber that is pressurized to a greater than sea level pressure. Current information indicates that the pressure be at least 1.4 atmospheres absolute (ATA). Common treatment pressures range between 2.0 and 3.0 ATA with typical treatment times of 90 -120 minutes of oxygen breathing at pressure.  USP medical oxygen is at least 99% oxygen. The time required to achieve near 100% oxygen in the chamber is dependent in part, on the size of the chamber, gas supply to the chamber, ventilation rate and pressure in the chamber. The time frame to achieve near 100% O2 in the class B chamber can range between 10 to greater than 30 minutes, depending on the variables involved.  This subject has not been adequately studied. 

We also encourage you to contact your chamber manufacturer to hear their response to this question. HBO ₂ therapy is a combination of time, pressure and Oxygen percentage. Due to this, it is critical that our equipment is as accurate as possible. Furthermore, the safety committee would like to see chamber manufacturers design systems that display the percent concentrations of oxygen in the atmosphere, and provide an accurate representation of the pressurized environment in atmospheres absolute and atmospheres measured.

REFERENCES

1. Undersea and Hyperbaric Medical Society, Hyperbaric Oxygen Therapy Indications, 13^th edition, Weaver, Best Publishing.
2. CGA G 4.3: 2015 Commodity Specification for Oxygen, 6^th edition, Compressed Gas Association
3. UHMS 2005 ASM meeting abstracts, Worth ER: Cochran, SK; Dale HM Oxygen Concentration Rise in a Monoplace chamber
4. Journal of Hyperbaric Medicine, Vol. 3, No. 1, 1988, Air Breaks in the Sechrist Model 2500-B Monoplace Hyperbaric Chamber, G.W. Raleigh, Rubicon Foundation Archive (http://rubicon-foundation.org)
5. [abstract] Interval to achieve 100% oxygen of monoplace chamber pressurization to 1.5 ATA, Weaver LK, Petty L, Bell J, Deru K, Churchill S, (http://rubicon-foundation.org)
6. UHM 2013, Vol. 40, No.2 – Hyperbaric Oxygen and Chronic Brain Injury, A Prospective trial of hyperbaric oxygen for chronic sequelae after brain injury (HYBOBI), figure 7, Churchill S, Weaver L, Deru K, Russo A, Handrahan D, Orrison W, Foley J, Elwell H, (http://rubicon-foundation.org) 
7. UHMS ASM meeting abstracts, 2017, Koumandakis G, Weaver LK, Deru K, Bell J Monoplace Hyperbaric Chamber Atmosphere Oxygen Concentration During Patient Treatment session
8. UHMS ASM meeting abstracts, 2018, Bell J, Koumandakis G, Churchill S, Weaver LK Observations on O2% during Air Breathing periods Using a Non-Rebreather Face mask in a Monoplace Chamber

Respectfully,

The UHMS Safety Committee

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

In Denver, CO with an atmospheric pressure less than sea level, how should the ordering physician compensate when prescribing hyperbaric oxygen therapy for a standard wound care table 2.0 ATA for 90 minutes? Please provide a detailed explanation.

Thank you for your question. The UHMS HBO2 safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

The decision whether or not to compensate for differential pressure due to altitude is the medical director’s responsibility. The US Navy requires altitude corrections for undersea divers starting at 1000 feet of altitude. We are not aware of conclusive data that indicates the outcomes are better or worse for patients because they were treated using gauge pressure versus atmospheres absolute (ATA) at altitude. In addition, our patients are fully acclimated to the altitude prior to starting treatment. We suggest that the chamber pressure should be as accurate as possible. There are certainly physicians/medical directors who choose to compensate for the differential pressure at altitude and those that do not.

We are not aware of any hyperbaric chambers with absolute pressure monitoring installed by the manufacturer. Most chamber pressure monitors use a gauge scale such as: feet of sea water/fsw, pounds per square inch/psig, atmospheres/atm, bar, kilo pascals/Kpa). These gauges inform the user what the pressure is inside the chamber with no regard to the outside ambient pressure. (note: the ATA or ATM marking from the manufacturer on your chamber is most likely a gauge pressure and not completely accurate above sea level). To calculate absolute pressure, one needs to include the surrounding ambient pressure. This pressure differs from facility to facility due to differences in altitude and a constantly varying local barometric pressure. Therefore, if one is to be accurate in the use of atmospheres absolute (ATA), an absolute gauge must be added to the chamber.

Denver is at an altitude of 5,924 feet and has an average barometric pressure of 12.2 pounds per square inch absolute (psia), 0.83 ATA. If a chamber at that altitude is compressed to 14.7 pounds per square inch gauge (psig) to achieve 2.0 ATA there will be an error of 2.5 psig or 0.17 ATA. The absolute pressure in the chamber would be 26.9 psia/1.83 ATA not 29.4 psia/2.0 ATA. The physician in Denver, CO wanting to achieve 2.0 ATA in the chamber will need to compensate for altitude by adding back the differential between altitude and sea-level by compressing the chamber to 17.2 psig.

We have seen facilities that have calculated the pressure to equal ATA for the various treatment schedules and posted these at the control panel. These are based on the average barometric pressure in their area. There are other facilities that have added absolute gauges to the chamber systems and verify the absolute pressure in the chamber daily.

Confirming pressure by calculation:
When limited to a pressure gauge using a gauge scale, the absolute pressure can be calculated (with reasonable accuracy) by adding the average barometric pressure for your facility found from a reliable source such as the blood gas lab, TcpO2 monitors, or weather sources. If using weather sources, confirm that the pressure scale they are using is the same as your gauge. Please note that airports report a standardized barometric pressure relative to sea level and it may not be the actual barometric pressure for your location.

Confirming pressure mechanically:
The most accurate way to confirm your chamber is at the absolute pressure prescribed is to install a calibrated absolute pressure gauge.

Things to consider:
1. The pressure relief valves should be checked to make sure that they will accommodate the increased pressure. Example, Denver to achieve 44.1 psia/3.0 ATA, the chamber will be compressed to approximately 32 psig. Monoplace chambers are designed for 30 psig working pressure.
2. The chamber manufacturer may need to be engaged as your chamber gauges are designed for sea level use: a monoplace chamber gauge may not display values above 30 psig and, in fact, the controls for a monoplace may not allow a pressure greater than 30 psig without adjustment.
3. If this is a multiplace chamber the increased chamber pressure to achieve ATA will affect the inside attendant’s sea level equivalent depth, and this must be accounted for in your procedures. Failure to take this into account may result in decompression illness risk for the inside attendants.
4. Is this undertaking warranted for your facility’s altitude? There is no right answer. Each facility needs to determine what is best for their situation.
5. Perform a risk assessment if chamber modifications are not supported by the chamber manufacturer.
6. Will this modification void your warranty?
7. If you undertake these changes, there is a need for enhanced staff training.
8. Update your maintenance program to address the additional gauge(s), as appropriate.
9. There may be issues not discussed here that are specific to your facility’s chamber(s).

References:
• U.S. Navy Diving Manual. Revision 7 Washington, D. C.: U.S. Government Printing Office; 2016.
• UHMS 2013 ASM, Abstract, Absolute Pressures for monoplace and multiplace chambers, Bell JE, Weaver LK, Churchill S, Haberstock D
• UHM 2014, Vol. 41, No. 6 – Altitude Decompression tables for HBO2 Attendants, James Bell, CHT/EMT/CFPS, Paul A Thombs, M.D., William J. Davison, CHT, Lindell K Weaver, M.D.,FACP, FCCP, FCCM, FUHM

Respectfully,

The UHMS Safety Committee

UHM_41-6_Altitude_deco_tables_for_IAs.pdf

Comment on FAQ: “How would an MD compensate for altitude in a monoplace chamber”

Absolute Pressures for monoplace and multiplace chambers

DISCLAIMER
Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet. If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, who can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility. Information provided on this forum is for general educational purposes only. It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

Is there any "standard" ascent rate for a class A chamber from 2.4ATA or what is the suggested rate? Currently we bring it up between 10-15 minutes.

Thank you for your question. The UHMS HBO₂ safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

The UHMS SC is not aware of any a standard decompression rate for a clinical class A chamber. Your current practice is typical of our experience.

When planning treatment profiles, it is important that the Medical Director and Safety Director of your facility consider the decompression obligation for the inside attendant and the risk of air trapping to the patient when addressing decompression rates. Patient comfort and chamber design are also important factors that should be addressed.

The decompression rate in the USN Air Decompression table of 30 fsw / minute (13.4 psig / minute) is fairly aggressive for patient care in the clinical chamber. It is the opinion of the safety committee that this rate is reserved for emergencies. The NFPA 99, 2018 edition, chapter 14, requires class A chambers to be able to decompress from 3 ATA to ambient pressure in 6 minutes (11 fsw or 4.9 psig per minute). These rates are intended to provide design parameters to chamber manufacturers.

For your consideration we have posted responses from several members of the committee related to this question:

• The USN and USAF have tables with standardized decompression rates such as the USN table 5 decompression rate of 1 fsw / minute (0.445 psig /minute)
• Linear decompression of 10 minutes at 2 psig / minute. The attendant wears an oxygen mask for 5 minutes at 2.4 ATA and during the 10 minutes linear decompression. We have no recollection of any DCS incidents with inside attendants since we switched to this protocol.  Part of our reasoning for the linear decompression was, our previous profile included a 10 fsw (4.45 psig) decompression stop, the decompression rate was faster and the chamber became uncomfortably cold.  Our chamber heating system at that time was not up to the task.  If we have a patient with pulmonary air trapping issues the physicians usually ask for a 15 minute ascent instead of 10 minutes (1.4 psig / minute).  All of our treatment tables use oxygen breathing by the attendant but not all treatment tables have a linear ascent.
• 2.4 ATA protocol for multiplace decompresses at 9.4 kPa /min (1.4 psig / minute) from 141 kPa (20.45 psig) for a total 15 min decompression time.  Attendants go on oxygen 5 min prior to starting decompression to provide a total of 20 min on oxygen for decompression of inside attendants. Note this exceeds USN that requires no stop or oxygen deco for this exposure but was selected for inside attendant safety.
• Typically a decompression rate of 7 fsw / minute (3.11 psig / minute) from 2.4 ATA to 10' (4.45 psig). Complete a 3 minute stop at 10 fsw (4.45 psig) for attendant decompression  and a rate of 5 fsw / minute ( 2.25 psig / minute) from 10 fsw (4.45 psig)  to surface.  A total decompression time of 10 minutes.  Attendants breathe O2 for 15 minutes before starting decompression.  Decompression is extended at the physician’s discretion for patients with lung issues, CHF, etc.
• Our attendants breathe oxygen for 30 minutes prior to decompression. Has to do with our altitude (3000 ft). Decompression is over 10 minutes from 45 fsw (20.0 psig). I always hesitate to put in ATA since we only use gauge pressure. It's approximately 2.2 ATA by the standard definition.
• Our typical decompression rate is 2 psig per minute. Our attendants were oxygen for 30 minutes of the treatment and during the 10 minute decompression. The decompression rate is extended by the MD if there are patient care concerns.

Respectfully,

The UHMS Safety Committee

DISCLAIMER
Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet. If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, who can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility. Information provided on this forum is for general educational purposes only. It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

Have there been any studies looking at the safety and efficacy of utilizing nitroglycerin patches in the hyperbaric environment to assist or improve circulation flow to a wound?

Thank you for your question. The UHMS HBO₂ safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

Regarding studies about patients wearing nitro patches for increased circulation at the affected site during hyperbaric oxygen therapy. 

• The safety committee is not aware of studies on this specific topic.

Since you did not identify what type of chamber we will respond to both class A and class B. The NFPA 99 2018 edition 14.3.1.6.2.2 describes how flammable agents could be allowed in class A chambers. 14.3.1.6.2.3 Prohibits flammable liquids, gasses or vapors in a class B chamber. There is little data on the fire risk of transdermal patches. In an attempt to evaluate safety, Lavonas (2006) reviewed the results of a structured literature search, performed an analysis “of the potential for creating fire in the hyperbaric environment was performed using standard chemical and hazardous materials references and formulae at a range of appropriate pressure and FO2 values” and reviewed data from product manufacturers. The results of this study suggest the risk of fire from transdermal patches to be low in both multiplace and monoplace environments (Lavonas, 2006).  

If the risk of fire is low, the medical necessity of the patch then becomes the driving factor. Historically, the concern has been erratic or unpredictable drug absorption rates due to vasoconstriction and adiabatic temperature changes in the hyperbaric environment. To date, there are no studies which examine this theoretical risk. One study examined the effects of scopolamine patches on navy scuba divers and found that “no unusual symptoms were seen as function of drug, pressure, or their interaction” (Schwartz, Curley, 1986).

The risk assessment on whether or not to allow transdermal patches has to be made by the medical director and safety director for each type of chamber and if the risk outweighs the benefit then the patch would not be allowed.  A common example of this would be the nicotine patch where we can usually get by for 2 hours or so without nicotine and the patches are not expensive therefore, we would prohibit them in the chamber.  On the other hand, fentanyl patches are expensive and there are facilities that have decided to use them in both class A and class B chambers. This decision and the risk assessment need to be documented and the exception signed by both the medical director and the safety director.

As for topical nitroglycerine enhancing wound healing through vasodilation and increased circulation, there have been a number of studies evaluating this effect.  References are included below for general discussion.

1. Lavonas, E.J. (2006). Safety analysis of transdermal medication delivery systems in the hyperbaric environment [Abstract]. Undersea and Hyperbaric Medical Society. Retrieved from: http://archive.rubicon-foundation.org/3673

2. Schwartz, H.J.C., Curley, M.D. (1986). Transdermal scopolamine in the hyperbaric environment [Abstract]. Retrieved from: http://archive.rubicon-foundation.org/3528
3. Mikaili P, Moloudizargari M, Aghajanshakeri S. (2014). Treatment with topical nitroglycerine may promote the healing process of the diabetic foot ulcers. Medical Hypotheses, 83(2), 172-174. doi: 10.1016/j.mehy.2014.05.002.

4. Coto-Segura, P., Ingelmo, J., Alonso, T., Sanchez-Sambucety, P., Rodriguez-Prieto, M.A. (2007). Effectiveness of topical application of nitoglycerin spray to increase survival of cutaneous flaps and grafts. Actas Demosifilogr, 98, 291-5.

5. Coruh, A., Abaci, K., Gunay, G.K. (2004). Effect of topical nitroglycerine on the survival of ischemic flow-through venous flaps in rabbits. Journal of Reconstructive Microsurgery, 20(3):261-6.

6. Hotkar, M.S., Avachat, A.M., Bhosale, S.S., Oswal, Y.M. (2013). Preliminary investigation of topical nitroglycerin formulations containing natural wound healing agent in diabetes-induced foot ulcer. Internation Wound Journal, ISSN 1742-4801. doi: 1111/iwj.12084

7. Pawasauskas, J., Perdrizet, G. (2014). Daily application of transdermal fentanyl patches in patients receiving hyperbaric oxygen therapy. Journal of Pain & Palliative Care Pharmacotherapy, 28, 226-232. doi: 10.3109/15360288.2014.938885

Published Date:      01/2016
Review Date:         01/2019
Due Review:          01/2022

DISCLAIMER
Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet. If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, who can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility. Information provided on this forum is for general educational purposes only. It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

If a facility performs off-label treatment is a separate informed consent recommended or required?

Published Date:   5/2016
Review Date:       4/2019
Due Review:        4/2022

Thank you for your question. The UHMS HBO2 safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

Regarding: Informed consent required for off label use.

Informed consent is required for any medical procedure. This is the responsibility of the medical director.

DISCLAIMER
Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

In an oxygen filled monoplace chamber are the same policies used as an air filled multi-place setting in regards to flying after treatment. I have been telling patients not to fly but wanted to double check anyways.

Published Date:   4/2016
Review Date:       4/2019

Thank you for your question. The UHMS HBO2 safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

The UHMS defines hyperbaric oxygen therapy (HBO₂) as an intervention where an individual breathes near 100% oxygen intermittently while inside a hyperbaric chamber that is pressurized to greater than sea level pressure. For clinical purposes this pressure should meet or exceed 1.4 atmospheres absolute of pressure while breathing near 100% oxygen.

If your patient is breathing near 100% oxygen there would be no restriction from flying we are aware of because of the HBO₂. There may be some other reason for not flying related to the patient’s medical condition, but the patient will not absorb enough nitrogen during HBO₂ in an oxygen filled monoplace to be at risk for decompression illness.

The inside attendant in a multiplace chamber would have restrictions on flying as they are breathing air for much of the time at pressure and; therefore, will need to follow the rules for divers like those from the US Navy diving manual.

For reference:

In chemistry, Henry's law is one of the gas laws formulated by William Henry in 1803. It states: "At a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid."

UHMS Hyperbaric Oxygen Therapy Indications, 13^th Edition

DISCLAIMER
Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

In the multiplace setting, what treatment table is used for Acute CO poisoning? When does tender go on O2? I was presented a Weaver Protocol that appears to have been developed for monoplace chambers as it has patients on O2 during descent and ascent and does not take into account a tender in a multiplace setting. Can anyone send me their Multiplace CO Treatment table?

Weaver, Bell, et al published a paper in 2002 in NEJM on how they operate in a multiplace environment for CO and they are at altitude. Also attached is their paper from UHM – see Figure 3.

Hampson, et al published two papers on the subject, including the 2012 paper addressing treatment pressure and the 2005 paper addresses treatment number.

Hyperbaric treatment of patients with carbon monoxide poisoning in the United States

The UHMS/CDC Carbon Monoxide Poisoning Surveillance Program Three-year data

Decompression tables for inside chamber attendants working at altitude

We treat patients on a treatment table in a multiplace chamber where we pressurize to 14 m or 46 FSW pressure equivalent (1 meter sea water = 3.29 foot sea water) for 100 minutes. USP O2/air break periods are 30 min`s USP O2, 5 min air and decompress in 7 min to the surface...

Published Date:      02/2017
Review Date:         02/2020

Question: We treat patients on a treatment table in a multiplace chamber where we pressurize to 14 m or 46 FSW pressure equivalent (1 meter sea water = 3.29 foot sea water) for 100 minutes. USP O₂/air break periods are 30 min`s USP O₂, 5 min air and decompress in 7 min to the surface. 

We want to know, can/should the inside staff member breathe USP O₂ during the first, second or third 30 minutes of the table to potentially avoid missing decompression if the treatment needs to be aborted.

The reason being, a few times we have had to abort the treatment because the patient is too unstable and if we start breathing USP O₂in the first or second 30 min`s period and need to abort the treatment and start decompression (slowly, no stops) after for instance 60 min`s, it will certainly not be a problem to go straight to the surface. It would most likely not be a problem if we go straight to the surface after 60 min`s breathing air at 14 m either, but we there is a concern of increased risk for the inside staff member.

So the questions:

• Is there a better treatment table to use? When do the inside staff members breathe USP O₂ and for how long?
• Have you heard of anyone else using a table where the staff are breathing oxygen routinely in the beginning of a treatment table?

Thank you for your question. The UHMS HBO₂ safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

There are several questions in this query and many possible ways of looking at this. This reply is assuming the chamber is at sea level (or at least below 1000 feet altitude).

The SC would recommend using the USN dive tables rev 7 Dec, 2016, as a gold standard for planning purposes. The standard air decompression table, entered at the exact or next greater pressure of 46 fsw would be the 50 foot profile which has a no decompression limit of 92 minutes. The treatment you describe would therefore require decompression for the inside attendant.  The USN 50 / 100 requires one of three choices; a 4 minute stop at 20 fsw pressure for 4 minutes breathing air, a 2 minute stop at 20 fsw breathing O2 or a direct decompression to ambient and back in the chamber and at 50 fsw pressure for 15 minutes of oxygen breathing using surface decompression with oxygen. Surface decompression using oxygen should not be used unless practiced and understood by all members of the team. The USN alternative shallow water tables (2A-1 ) has an option for 46 fsw which has a no decompression limit of 116 minutes which would work well for an inside attendant on a 46 fsw for 100 minute treatment profile. (1)

Oxygen is certainly being used as a safety measure for inside attendants in multiplace chambers. This is done most often at the end of the treatment and during decompression. This practice has been called “zero time” as the nitrogen clock essentially stops when breathing oxygen at pressure. Since this practice is not scientifically validated, the use oxygen is an adjunct and not a mechanism to stop the bottom time. The USN air tables should be used as written and as if the inside attendant was breathing air for the entire time, regardless of oxygen use or not. At 46 fsw (2.4 ata) we would be concerned that the inside attendant be seated and at rest during oxygen breathing. Unless there is another inside attendant in the chamber the mask(s) should be held in place and not strapped on. (1)(2)

There are computer models that can be used to supplement the USN diving tables in order to calculate the benefit of oxygen. These models should be taken as secondary sources in your planning. (3) Your physician may also want to look at treating at 45 fsw (2.36 ata) or other pressures for the safety of your IA.(4)

If you have not already done so we would encourage you to build Early Treatment Abort Procedures for all of your treatment profiles and practice them.  These abort profiles should enable you to manage medical, mechanical and other changes quickly without putting your IA at a unreasonable risk for decompression sickness.

References:

• USN Dive tables rev 7, Dec 2016 (http://www.navsea.navy.mil/Home/SUPSALV/00C3-Diving/Diving-Publications/ accessed 1-16-2017
• Hyperbaric Facility Safety: A Practical Guide, Wilber T. Workman, Best Publishing, https://www.bestpub.com/books/product/cid-124.html accessed 1-16-2017
• Davis Laboratory- Down loads page http://tanktigers.net/Tech.htm accessed 1-16-2017

How the Davis 2.36 ATA wound healing enhancement table was established, UHM 2004, Vol. 31, No.2 Mini forum on oxygen toxicity and air breaks in HBO₂ therapy (https://www.uhms.org/resources/archived-publications.html# accessed 1-16-2017

DISCLAIMER


Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

What is the emergency procedure when an oxygen leak is recognized in a mono chamber?

SC Response regarding the emergency procedure for a recognized oxygen leak around a monoplace chamber.

The question does not define the extent of the leak. Leaks from the monoplace chamber can be a serious safety concern, something that can be managed quickly and easily by the chamber operator, or somewhere in between. The treatment should not be continued if the leak cannot be identified and fixed easily.

Minor leaks such as from an IV pass-through not tightened up can be fixed without interrupting the treatment. Items caught between the door seal and the chamber can cause leaks; sheets, pillow cases, tubing, small tears in the seal etc… in some cases the chamber will need to be decompressed and the seal checked or even replaced.

Major leaks that cannot be repaired easily by the chamber operator, or outside of the operator’s qualifications, should be referred to the chamber manufacture and/or the person responsible for the maintenance of the chamber. The chamber should be taken out of service until the leak is repaired.

We would encourage the user to follow the manufacturer’s recommendations for the installation and operation of any chamber.

A suggested procedure could be:

                                                            Oxygen Leak

DISCLAIMER
Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members can provide medical diagnoses or recommendations for equipment over the internet.  The responsibility for medical diagnoses and treatments resides with the medical director; approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.

One of our International customer is planning to install Hyperbaric chambers on 7th floor (80 ft roughly). Structurally it is not an issue, they are asking is it safe to use Hyperbaric Chambers in 80 ft altitude?

Thank you for your question. The UHMS hyperbaric oxygen safety committee (SC) can provide information, guidance and an opinion; however, the ultimate responsibility for these types of questions lies with the medical director and safety director of your facility.

SC Response regarding the safety of a Class B chamber located on the 7^th floor of the building.

The SC is aware of many hyperbaric facilities that have class B and / or class A chambers located above or below the ground level of a building. We are aware of hyperbaric facilities located at altitude, Denver, Colorado, USA (alt 5280 feet) for example, that well exceed the 80 feet altitude referred to in the question.

This following is not a definitive list. The SC is not in a position to be a consultant for chamber installations. In general, the room housing a chamber requires that:

• The floor of the building can support the weight of the chamber(s).
• Medical gas supplies are plumbed in accordance with local hospital codes.
• The electrical design of the room housing the chamber(s) allows for the chamber to be grounded.
• The exhaust from the chamber is to the exterior to the building.
• That emergency lighting and communication or alarms coupled to the emergency fire service are installed.
• There is sufficient room to house the chamber(s), or in other words, in an emergency, the ingress and egress from the room is acceptable to the local authority.
• The room housing the chamber is for the exclusive use of the hyperbaric operation.
• Appropriate safety signage is placed in applicable locations.

We would encourage the user to follow the manufacturer’s recommendations for the installation and operation of any chamber.

The National Fire Protection Association (NFPA) 99 Heath Care Facilities Code 2018 edition, chapter 14 Hyperbaric Facilities, is an invaluable resource even if your facility is not located in the USA. (https://www.nfpa.org ).

We would also encourage the user to download and use the 4^th edition of the UHMS Hyperbaric Facilities Accreditation Manual from the UHMS web site as a guide to operations.  

DISCLAIMER
Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members can provide medical diagnoses or recommendations for equipment over the internet.  The responsibility for medical diagnoses and treatments resides with the medical director; approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.

We are finding it problematic to come up with an institutional guideline for the treatment of central retinal artery occlusion due to ambiguities in that section of the UHMS HBO2 Therapy indications, 13th Ed. How would you word it for use in a teaching institution?

Between Dr. Heather Murphy-Lavoie’s paper on the initial management of CRAO with HBO2 and the about-to-be-published paper on follow-up management of this disorder, the UHM has the best set of clinical practice guidelines that I am aware of for this disorder.

Case Report: Management of central retinal artery occlusion following successful hyperbaric oxygen therapy: case report; UHM 2018, Vol. 45, No. 1

A colleague said that he heard at an HBOT symposium, that a patient could actually be at greater risk for an oxygen toxicity seizure right after they complete a scheduled air break. Could you share your thoughts on this and is there any study or literature that supports this? We are still giving air breaks for any Tx depth >2.0 ATA and screen patients carefully for those that might be at greater risk for OTS. thanks.

Question answered by UHMS HBO2 Committee member Michael Bennett, MD:

As far as I am aware, there are no data to support this phenomenon. The 'off-oxygen' effect is completely anecdotal I think. and I am not at all sure if oxygen breaks confers any benefit or harm in this respect. 

Is Hyperbarics safe for a patient that has a granuloma on the lung? He also has emphysem/copd to show up but denies complication and his past medical records do not address any issues.

Have you seen this MEDFAQs on COPD https://www.uhms.org/resources/medfaqs-frequently-asked-questions-faq/60-medical-patient-care.html?

“Is there a protocol for treating a patient with COPD?

There are three issues:

1. The effect of an increase in PO2 and breathing gas density on work of breathing and PCO2. Patients who have severe airways obstruction or who have chronic hypercapnia may develop respiratory distress and elevated PCO2, respectively.
2. Increased risk of pulmonary barotrauma. AGE has been reported in bullous lung disease during altitude exposure (one such case report is attached). AGE has also been reported after hyperbaric oxygen therapy (see Wolf, attached), although rarely.
3. Whether a therapeutic PO2 can actually be achieved.

In practice, at Duke University do not administer HBO2 to patients with resting dyspnea, baseline hypercapnia or radiographically evident bullae on plain chest x-ray. For patients with baseline hypoxemia we use room air ABGs and a prediction algorithm (see 3 attached references) to estimate whether a therapeutic arterial PO2 (arbitrarily PO2≥1000 mmHg) will be achieved.”

There are numerous attachments that go with the FAQ.

Can you please tell me in an emergency what is the fastest and safest time we can bring a Pt back up to 1ata from 2.4 ata in a monoplace chamber

Thank you for your question. The UHMS hyperbaric oxygen safety committee (SC) can provide information but the ultimate responsibility for these types of questions is with the medical director and safety director of your facility.

The answer to your question is dependent upon the emergency decompression rate selected by your facility and the capability of your particular chamber. Additionally, it is important to assess the risk of rapid or maximum decompression, as the rate may be designated by the particular emergency or medical condition of the patient.

• We suggest that the maximum decompression rate for the facility be decided by the medical director and safety director. This detail should be reflected within the facility’s emergency procedures, and the capability tested routinely as part of the facilities’ preventive maintenance program.
• Consider the emergency in your decision to rapidly decompress. In some cases, it may be prudent to decompress rapidly but not at the maximum rate. The medical condition of the patient, active shooter, severe weather, mechanical failure, and the ability to egress are just a few factors to contemplate. Of course, in the case of fire inside the chamber, the maximum decompression rate is recommended.
• Although applied from air decompression schedules, it is known that some facilities have previously adopted the maximum decompression rate of 30 feet of seawater per minute as described in the U.S. Navy Diving Manual, Revision 7, Volume 2, Chapter 9.
• By this measure, decompression from 2.4 ATA would occur in approximately 92.4 seconds. However, it is important to note that this rate applied at 3 ATA would be too slow to meet the NFPA requirement of 2 minutes from 3 ATA (132 seconds).
• UHMS Clinical Hyperbaric Facility Accreditation Manual, Fourth Edition HBOO 7.1: “The ability to decompress a Class B monoplace chamber from 3 ATA to surface in less than 2 minutes is documented.”
• 2018 NFPA 99, chapter 14 states that monoplace (class B) chambers ”shall be capable of depressurizing from 3ATA in no more than 2 minutes.”
• It is important to read the above references carefully, as the requirement states that the chamber must be capable of decompression at this rate (1 ATM per minute). It does not say that this is an acceptable rate in every emergency.

Respectfully,

The UHMS Safety Committee

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

What is the proper management of gastric tubes in the Monoplace HBO chamber?

Date posted:  9/21/2019

Thank you for your question. The UHMS HBO2 safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

For the Monoplace environment, it is reasoned that Gastrostomy tubes (commonly known as G-Tubes) may remain either closed or open during therapy and throughout pressure changes. Your facility’s Hyperbaric Medical Director should make the determination based upon the needs of your program. Here are several considerations that may aid you in determining the best approach for your facility:

• It is recommended that the disposition of the tube remain static (open or closed) throughout therapy to reduce the potential for air trapping and rapid release of air and fluid (Boyle’s Law).
• Open G-tube ends may be wrapped with sterile gauze to contain any potential drainage.
• Closed G-tube ends may also be wrapped, in the event of accidental opening.
• Closed G-tube ends may reduce the amount of drainage, but require an additional step to complete before and after therapy. You may wish to adjust your pre/post therapy checklists accordingly.
• After therapy, you may wish to check the tube for patency and proper function prior to departure.

Respectfully,

The UHMS Safety Committee

 DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

Is there any literature or consensus about treating patients less than 5 days a week on a regular basis? We have a patient who can only come 3 days a week due to his work. Is it only the total number of treatments received that matters or does the time frame in which it is received also important? (not referring to Marx protocol patients).

Date posted: 9/21/2019

Thank you for your question. The UHMS HBO2 safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

There is significant interest in this question throughout the hyperbaric community as there are a number of occasions where circumstances often prohibit consecutive hyperbaric therapy. The committee refers you to resources such as Pubmed and the Rubicon Foundation. A literature search has revealed the following result:

Rate of delivery of hyperbaric oxygen treatments does not affect response in soft tissue radionecrosis.

Given that this study represented a response rate in soft tissue radionecrosis only, the committee does not propose that this logic be applied universally to all other indications for hyperbaric oxygen therapy.

Respectfully,

The UHMS Safety Committee

 DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

In the Monoplace chamber, is it always proper to turn off oxygen supply if there is a fire in the chamber? It is very logical to cut off O2 which is fueling fire, however at another class we were told never to turn off O2 because you then lose control of chamber. Which is correct?

Posted: 9/21/2019

Thank you for your question. The UHMS HBO2 safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

It is well known that the reduction of pressure is proven to decrease the rate and intensity of an oxygen-enriched fire. It is this committee’s opinion that in the event of a fire in the Monoplace chamber, maximum decompression should not be delayed as the heat of combustion will significantly contribute to increasing pressure in the chamber. As such, rapid evacuation of the patients and staff in the immediate and surrounding areas is critical.

Additionally, it is imperative that each hyperbaric facility contact their chamber manufacturer to understand the behavior of their emergency ventilation controls associated with their particular chamber model and system design. When describing the system to the manufacturer, consider any potential system modifications that may have occurred since installation.

You may also consider:

• A test of your system with and without gas supply during decompression to understand how the system behaves. Consider the time required to decompress and the impact on facility evacuation and perform fire drills with each of these scenarios in mind.
• Develop your emergency procedures to reflect the behavior of your particular system. NFPA 99, Annex B.14.3.2 contains guidance in drafting the emergency procedures for fire in a Class B chamber.
• It is also important to perform a timed test of the emergency ventilation function periodically per the manufacturer’s maintenance recommendations.
• Once all chambers have been decompressed, it is common for emergency procedures to include the shutdown of oxygen supply at the zone valves prior to evacuation or relocation.

Lastly, the Safety Committee has reached out to two Monoplace chamber manufacturers to address this question. Each of them confirmed that the emergency ventilation function installed on their chambers require a gas supply in order to operate normally. These manufacturers also stated that when the emergency ventilation function is activated, the inflow of oxygen to the chamber ceases.  The gas supplying the actuating valves that keep the exhaust valve open will remain, so that the chamber can fully decompress. Again, it is important to confirm and test the function of your particular chamber, as there are many variations of this design. Your understanding of this design will lead to a procedure that will dictate a series of life saving events. Therefore, this question is one that should be asked and answered by every Hyperbaric Safety Director and Medical Director.

Respectfully,

The UHMS Safety Committee

 DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

I work in a clinic setting with wound care on one side of the building and I am alone on my side with HBO2. My boss would like to put a push button code lock on my door and I'm wondering if this is permitted? If there was a fire I'm concerned about the Fire Department not being able to get in. Does anyone have a similar issue? Is it ok to have this type of device on the HBO2 room door? We need some type of Safety policy and procedure for an active gunman in the building and I’m not sure how to go about th

Published Date:      02/2017
Review Date:         02/2020

Question:  I work in a clinic setting with wound care on one side of the building and I am alone on my side with HBO2. My boss would like to put a push button code lock on my door and I'm wondering if this is permitted? If there was a fire I'm concerned about the Fire Department not being able to get in. Does anyone have a similar issue? Is it ok to have this type of device on the HBO2 room door? We need some type of Safety policy and procedure for an active gunman in the building and I’m not sure how to go about this.

Thank you for your question. The UHMS HBO₂ safety committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the medical director and safety director of your facility.

Security is a real concern and we agree that Hyperbaric Facilities need to develop Policy and Procedures to manage active shooter / Code Silver, Bomb threats and other security concerns. We are required by NFPA 99, chapter 14, to have emergency drills on a regular basis. These threats should be added to your emergency response plans.

The SC would refer you to your local Authority Having Jurisdiction (AHJ). There are codes and regulations regarding locked doors. For guidance you can start with NFPA 101 Life Safety Code, 2018 edition, 5-2.1.5 Locks, Latches and Alarm Devices and NFPA 99, 2018 edition, Chapter 13, Security Management. Work with your local AHJ and Safety and Security department, possibly Emergency Management, to complete a threat assessment. These resources will help decide if a key pad is necessary.

In general, we see no issue with a cipher lock on the entrance to the hyperbaric suite. In fact, we are aware of many facilities with ID badge, card access, push button locks and even keyed doors entering the room housing the chamber(s). The Fire Department will be able to gain access in the event of an emergency. Consideration should be given to enabling not only the Fire Department, but other responders such as code teams or security. The chamber room can be considered a restricted area with authorized entry only. The concern is that evacuation in the event of an emergency is not hindered. There must always be an exit path, and the lock mechanism must not impede egress (or ingress of authorized personnel).

We also note that a chamber operator working alone is concerning. NFPA 99, 2018 edition, chapter 14 requires that there be a qualified chamber operator at the control panel with visual and audible communication with the occupants any time the chamber is in use. We would encourage the use of the UHMS Guidelines for Hyperbaric Facility Operations, 2^nd edition, Section 3, Staffing Guidelines, to staff the chamber operation. Consider how to ensure the safety and security of the single operator and any patients being treated, as described in this question. Is there a communications link for immediate help? Consider a panic button or regular rounding (closed circuit video feed?) by someone to check on the chamber operator and patients to provide support as needed. During your emergency drills, do you have the help you need to manage the number of patients? 

We have a pt that has been referred for HBOT for radiation cystitis. He has an artificial sphincter which has pump that is filled with saline. The manufacturer does not have information on safety in the HBOT chamber. Does anyone have information on this.?

Date: 9/28/2020
From: UHMS HBO2 Safety Committee

Q:

We have a pt that has been referred for HBOT for radiation cystitis. He has an artificial sphincter which has pump that is filled with saline. The manufacturer does not have information on safety in the HBOT chamber. Does anyone have information on this?

A:

Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Medical Director and Safety Director of your facility.

Several members of the UHMS HBO₂ Safety Committee have expressed no concerns allowing implanted artificial urethral sphincters. This is mainly due to the fact that these devices are fluid filled and wholly enclosed in the body, and therefore changes in atmospheric pressure should not affect its operation or cause harm to the patient.

As a precaution, the committee recommends discussing this with the patient’s urologist and including them in the decision-making process. We also suggest documenting your risk assessment well and ensuring that the information is shared with the patient as part of the informed consent process. The UHMS HBO₂ Safety Committee considers this device to be compatible in either the Monoplace or Multiplace hyperbaric environment.

DISCLAIMER
Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet. If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility. Information provided on this forum is for general educational purposes only. It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally. 

Respectfully,

The UHMS HBO2 Safety Committee

I work in a multiple facility and a patient posed a questions to one of my techs that I was not here to help discuss. The question was "why do we not use an alcohol swab when we check blood sugar levels toward the end of the treatment?" History, we do an in chamber post treatment blood sugar check on a with about 8ish minutes remaining at pressure. We use a standard 2x2 cotton swab to wipe the figure of the patient prior to the lancet. I know an alcohol swab has a low flash point, and in my prior 2 years

Date:       9/28/2020
From:      UHMS HBO₂ Safety Committee

Q:

I work in a multiple facility and a patient posed a questions to one of my techs that I was not here to help discuss. The question was "why do we not use an alcohol swab when we check blood sugar levels toward the end of the treatment?" History, we do an in chamber post treatment blood sugar check on a with about 8ish minutes remaining at pressure. We use a standard 2x2 cotton swab to wipe the figure of the patient prior to the lancet. I know an alcohol swab has a low flash point, and in my prior 2 years of operating in a monoplace facility, I did not use alcohol swab pre or post treatment. Just a 2x2 swab. I am curious where y'all stand on the use of alcohol swabs for an in chamber blood sugar? Any thoughts will be appreciated.

A:

Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate decision and responsibility for these types of questions rests with the Medical Director and Safety Director of your facility.

          The UHMS HBO₂ Safety Committee can provide guidance but cannot endorse a specific product for use in the multiplace hyperbaric environment to cleanse the skin before a capillary finger stick procedure for glucose scanning. The decision to allow items containing alcohol that could increase the probability of fire within the hyperbaric environment should be carefully made by the Hyperbaric Safety Director and Hyperbaric Medical Director of your particular facility. Swabs containing 70% isopropyl alcohol do emit vapors that are easily ignitable within the multiplace hyperbaric environment if in close proximity to an ignition source. However, it is plausible to consider limited and controlled amounts of this material after careful consideration of the risks and benefits involved.

• We recommend before choosing a product that a proper risk assessment is performed by the Hyperbaric Safety Director and Hyperbaric Medical Director; with careful consideration given to the flammability, NFPA 704 rating of the material, amount, potential vapors released, chamber volume, and the fuel load added to the environment.
  • For more information related to this topic, please refer to NFPA 99 section 14.3.1.6.2 – Flammable Gases and Liquids (2018).
  • You may wish to seek an alcohol–free option like Benzalkonium Chloride wipes. It is important to work with the laboratory and infection control practices within your institution to determine the best option for your practice.
  • We strongly encourage that all hyperbaric facilities own a copy of the NFPA 99 in their library. You can find read only, free access to all the NFPA codes at http://www.nfpa.org/. You may also wish to consider the NFPA-99 Health Care Facilities Handbook, a valuable resource containing an expansive explanation of the NFPA-99.
• We would also encourage you to share your methods with the laboratory or infection control teams within your institution who are responsible for setting the policies related to this procedure and educate them on the unique nature of the hyperbaric environment. We would advise you to work with these teams to develop a specific procedure related to glucose scanning within the hyperbaric environment of the multiplace chamber to ensure that you are in compliance with local guidelines.

Respectfully,

The UHMS HBO₂ Safety Committee

 DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

I work at ***** and am often a single chamber operator (Monoplace). Our manager is trying to come up with a safety measure for if the chamber operator would go down. They have talked about placing some sort of emergency button inside chamber as a way for the security office to be notified if I were to go down. In the past, our manager would call on the telephone to check on us or security will round by the clinic. Security officers have not been able to do that due to staffing issues. Our chamber is down

Posted: 10/12/2020

Q:
I work at ***** and am often a single chamber operator (Monoplace). Our manager is trying to come up with a safety measure for if the chamber operator would go down. They have talked about placing some sort of emergency button inside chamber as a way for the security office to be notified if I were to go down. In the past, our manager would call on the telephone to check on us or security will round by the clinic. Security officers have not been able to do that due to staffing issues. Our chamber is down in the basement of the main hospital and literally off the path of heavy traffic by others. I have stressed the importance of staffing but at this time extra staffing is not an option. Have you ever heard of an in chamber notification system that could be looked into? Any advice would be appreciated.

A:

Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Medical Director and Safety Director of your facility.

The UHMS HBO₂ Safety Committee agrees that this scenario is a legitimate concern for monoplace facilities with limited staffing. Several committee members have either encountered this question in their own experience, or have seen several worthy solutions while performing site surveys as a UHMS surveyor. The committee has previously addressed this subject in brief while answering other questions (See references below). However, we will provide a more direct and detailed answer here for your benefit.

The committee will list several options for your consideration below. Before implementing any of these solutions, it is important to note that the staffing, education, and training of personnel responsible to the monoplace hyperbaric facility are paramount to any signaling device, security system, or policy. These measures will only be successful if properly implemented into your program.

Alarm Systems:

• The committee is aware of a facility that has utilized an emergency push button installed at the chamber operator's desk.  When pushed, an alarm would sound at the nearby nursing station and nursing staff would immediately respond. This solution could be helpful to alert staff to a variety of urgent or emergent needs.
• While the creation of a non-electrical, pneumatically-controlled alert switch located inside the monoplace chamber is technically possible, the committee would caution you from placing the responsibility of monitoring the chamber operator in the patient’s hands. Any modification of the chamber or the creation of a switch of this nature must be either endorsed by or created and installed by the manufacturer. This committee does not endorse the use of electrically-powered, wired or wireless technology for this purpose in a monoplace hyperbaric chamber. Electrical components to include speakers (used for entertainment and communication) and physiological leads within the monoplace hyperbaric setting are intended to be designed and installed by the manufacturer, as the NFPA 99 prohibits the use of electrical components for anything other than patient physiological leads and communication functions (NFPA 99, 14.2.9.6 -  14.2.9.6.3 and annex material A.14.2.9.6.1.1)
• For monoplace applications, this committee does not recommend the use of an automated decompression or signaling switch, which are sometimes used in multiplace systems and is usually located outside of the chamber. In this instance, the alarm is initiated and decompression begins if the timer is not reset periodically by the operator (this is commonly referred to as a “dead man’s switch”). In the monoplace setting, this could place the patient at risk for suffocation if response is delayed, as the chamber door could remain sealed at the surface without gas flowing.

Staffing Considerations:

• The UHMS HBO₂ Safety Committee agrees with the following staffing guidelines provided in “UHMS Guidelines for Hyperbaric Facility Operations, 2^nd ed.,” as it relates to Monoplace facilities:

Section 3, Staffing Guidelines (pg.15):

       “One (1) chamber operator should not operate and/or monitor more than two (2) monoplace chambers simultaneously during patient treatments”

       “At least one (1) additional hyperbaric-trained staff member should be immediately available to assist, if needed, during any patient treatment.”

Section 3, Staffing Guidelines – I. Physician/NPP Staffing Guidelines (pg.15-16):

       “Physician staffing should provide coverage of the following clinical safety provision(s): Coverage of patients for consultation and treatment supervision during published working hours in strictly outpatient facilities.”

       “Physician staffing should provide coverage of the following clinical safety provision(s): Physician or non-physician provider supervision and be readily available during treatments.”

• The Baromedical Nurses Association also supports the UHMS’s staffing guidelines for monoplace operations within a hyperbaric facility.
• Ensure that the Hyperbaric Safety Director is working closely with the Hyperbaric Medical Director to establish the minimum complement of staff as indicated in the UHMS Clinical Hyperbaric Facility Accreditation Manual, UHMS Guidelines for Hyperbaric Facility Operations, 2nd ed., and NFPA 99 14.3.1.4.2.

Security Cameras and Monitors (video and in-person):

• Perhaps a more practical solution to your concern is a closed-circuit monitoring system (CCTV) with someone positioned elsewhere (front desk or security personnel) keeping an eye on the chamber room. It is possible that motion sensor technology could also be used to ensure that the operator is present. Additionally, an alarm could be triggered if there is no movement after a period of time.
• More than one Safety Committee member has seen CCTV used at UHMS-accredited facilities while serving as an accreditation surveyor and recommends this solution.
• Considering the location of your chamber facility and the staffing situation you describe, we encourage you to revisit and enforce your “working alone” policy requiring your supervisors to establish a consistent means of communication with the operator. We encourage your Medical and Safety Directors to be active participants in the enforcement of these policies for the safety of every patient and chamber operator.

Respectfully,

The UHMS HBO₂ Safety Committee

REFERENCES:

UHMS HBO2 Safety Committee response to MEDFAQ, Accessed 9/28/2020, Originally published 2/23/2017.

Workman, W. T. (2015). Guidelines for Hyperbaric Facility Operations (2nd ed.). North Palm Beach, FL: Undersea and Hyperbaric Medical Society, Inc.

National Fire Protection Agency (NFPA). (2018). NFPA 99 2018 Edition: Health Care Facilities Code. Quincy, Massachusetts.

Undersea and Hyperbaric Medical Society. (2018). Clinical Hyperbaric Facility Accreditation Manual (4th ed.). North Palm Beach, FL: Undersea and Hyperbaric Medical Society, Inc.

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

While we have long restricted the ascent rate to 3 psi/min to lessen the possibility of a lung bleb rupture with resultant pneumothorax, we cannot find a physiologic reason to restrict the descent rate other than to avoid barotrauma. We have used a descent time ot at least 10 minutes from surface to 2.4 ATA which has not really been a concern in the past because the compressors could not achieve depth much faster than that. However, our new compressors can easily achieve depth in 6-7 minutes. Is there

Posted: 2/17/2021

Q:
While we have long restricted the ascent rate to 3 psi/min to lessen the possibility of a lung bleb rupture with resultant pneumothorax, we cannot find a physiologic reason to restrict the descent rate other than to avoid barotrauma. We have used a descent time of at least 10 minutes from surface to 2.4 ATA which has not really been a concern in the past because the compressors could not achieve depth much faster than that. However, our new compressors can easily achieve depth in 6-7 minutes. Is there a reason, other than patient comfort and barotrauma avoidance, to restrict the descent rate?

A:
Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Medical Director and Safety Director of your facility.

The UHMS HBO2 Safety Committee is not aware of a uniform descent rate that should apply to all profiles and settings. Descent rates are generally considered to be part of the treatment protocol designed by the Medical Director and Safety Director of your facility. When planning treatment profiles, it is important that the Medical Director and Safety Director of your facility consider, as you stated, the risk of barotrauma to any of your patients. Keep in mind that the design of your plant (Oxygen supply for monoplace, compressor air for Multiplace) can also be a deciding factor when choosing an appropriate compression rate for your facility. Patient comfort (noise level, adiabatic heating caused by compression, and ease of ear clearing) can be a significant factor that should be considered.

It is also important that operators are aware of and follow the treatment profile; as it is an extension of written orders from the Hyperbaric Physician. Hyperbaric physicians commonly describe travel rates/times in the therapy note that supports Physician supervision. These travel rates/times may even be required by some insurance carriers.

From a broader perspective, it is noted that compression rates may vary among commonly accepted profiles. For example, the US Navy standard descent rate for all USN profiles is a very aggressive 20 fsw / min (8.82 psig / min). Even so, they note “Descent rates may have to be decreased as necessary to allow the patient to equalize.” However, one must consider the critical application of many US Navy profiles, as they are mainly designed to treat injured divers.

In 1998, the US Air Force published a paper defining the concept of non-linear (aka curvilinear) descent and reported a reduction in the incidence of barotrauma when using non-linear versus linear descent. Most chambers that utilize computer software to drive their profiles have been known to use a non-linear descent profile. Several references to this approach are listed in the references below.

It is common for clinical hyperbaric medicine practices to design their descent rates to accommodate the average patient. For your consideration we have posted responses from several members of the committee related to this question:

• For our routine scheduled treatments of 2 ATA for 2 hours we use a descent rate of 15 minutes to treatment depth. Several years ago, our Medical Director reviewed the data and felt that we could decrease otic barotrauma rates by slowing our descent rate. It helped decrease our barotrauma some but didn’t eliminate it entirely.
• On our emergency treatments, when we use a 2.8 for 85 min. or 2.45 for 90 min., we attempt to reach treatment depth in under 4 minutes to limit decompression obligations for the tender as much as possible.
• We would use a 10-15min descent rate to 2.4ATA on first time divers. Then bump it to 7min or less if the group could handle it. My seasoned dive patients (after about 20 treatments) could get there in 3-5min.
• We descend from 0 to 45 fsw in 6 minutes for the TT9. Our computers run a curved descent which starts off slow, then steadily increases as you go.
• During the “old days” when we pressurized manually, we pressurized as fast as the pt/tender would allow; often reaching 60 fsw in 3 minutes. One thing I’ve noticed over the years is sometimes going too slow can delay ear clearing, especially on pts that aren’t familiar with the process…sometimes they need that quicker “push” to pop/clear their ears.
• We have found patients struggle to descend faster than rate set 1.5 psi/min at this clinic location unless they have bilateral myringotomy tubes. This was not the case for my ten years in Kansas City. It causes me to wonder if there is an accustomed lower air pressure bias for those at my current altitude in Colorado. This clinic is at 4,995 feet whereas my clinic in Kansas City was at 861 feet elevation above sea level.
• Some patients may not notice the pressure change often enough if the descent rate is slowed, and this can lead to increased risk of barotrauma.
• We have operated at 4,500 feet of altitude for decades and our need for TM tubes is rare. The percent volume change altitude to any given chamber pressure is more than from sea level to that pressure. We generally compress at 1 to 2 psi/minute but often compress faster in patients that equalize ok.
• I think we would all agree that making the patient’s descent pleasant and successful is critical to HBO- especially in the first compressions. It is an essential part of patient continued participation and long-term treatment compliance. Some patients claim to be fine until in excruciating pain. Slower compression rates are far more successful without a patient asking for a stop due to discomfort.
• Adiabatic heating caused by compression is another confounding factor that distracts the patient from their ear equalization. TV or other distractions should also not be turned on during compression.
• A combination of good patient equalization training, slow and well-ventilated compressions and eye to eye contact between technician and patient makes for a successful treatment.
• Compress at a rate as tolerated by the patient having the most difficulty clearing their ears, but not to exceed xx psi/minute. (as determined by the medial director and safety director)
• Equalization education should be an ongoing focus! In my experience, some people are forgetful from one day to the next. They also become complacent once they have been successful at reaching treatment pressure without issue.
• For treatment runs with multiple patients, remember having a new patient that needs a slower descent rate can affect others who may have gotten used to a specific rate used earlier in the week.
• Remember not all patients are successful using the same ear clearing technique, so be sure to teach different methods.
• The chamber is a machine. We control how fast it compresses (rate, change in rate and can even ascend 2 fsw) all to provide a safe arrival at treatment pressure.
• Assess possible barotrauma post treatment. With medical follow-up as needed.
• Note: At our facility in Denver the standard treatment is at 2.4 ATA, and the compression rate is limited to as tolerated, but not to exceed 9 fsw/minute. We usually operate in the 4 - 7 fsw/minute range as tolerated by the slowest patient. Our barotrauma rate was 2% in 2020. We spend a lot of time on focused education from day one and continue this throughout their treatment plan.

Respectfully,

The UHMS HBO2 Safety Committee

REFERENCES

Naval Sea Systems Command. (2016). “US Navy Diving Manual (7th ed.).” United States Navy Publication.

Zwart BP. (1998). “The "smooth ride" profile: Development, implementation, and evaluation of a hyperbaric chamber descent and ascent based on a constant rate of volume change with time.” Brooks AFB, Texas.

Environmental Tectonics Corporation. (2020) “Bara-Med “Smooth-Ride.” Weblink

Peterson RE. (2008). “Alternative Pressure-Change Profiles for Hyperbaric Oxygen Therapy.” Today’s Wound Clinic, 2(4). Weblink

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

Where is it written, or is it just common practice, that if you only have ONE supervising medical practitioner on site…that they do not go in the chamber unless for an emergency?

Posted: 7/16/21

Q:
Where is it written, or is it just common practice, that if you only have ONE supervising medical practitioner on site…that they do not go in the chamber unless for an emergency?

A:
Thank you for your question. The UHMS HBO2 Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Hyperbaric Medical Director (HMD) and Hyperbaric Safety Director (HSD) of your facility.

The UHMS HBO2 Safety Committee realizes that this is a very important question for facilities with multiplace hyperbaric chambers to answer, as it will impact how your team will handle various patient emergencies and potential staffing shortages. It is important to note that the NFPA 99 (2021), 14.2.1.4.2 gives joint authority to the HMD and HSD to determine the “minimum staff qualifications, experience, and complement based on the following:

• Number and type of hyperbaric chambers in use
• Maximum treatment capacity
• Type of hyperbaric therapy normally provided”

As such, the UHMS HBO2 Safety Committee recommends that a written policy is developed by the HMD and HSD that identifies the staffing levels necessary for the safe delivery of hyperbaric oxygen therapy based upon the above factors, and perhaps several other considerations that may be unique to your particular program.

Although there may be dire situations where it is necessary, the UHMS HBO2 Safety Committee strongly suggests that you consider other alternatives to the availability of the supervising Hyperbaric Provider when determining your inside attendant needs. We present to you that this individual is largely responsible for many operations within the clinic while a therapy is underway, and that the use of a provider in the chamber is necessary by exception only, as described in the USN Dive Manual and referenced in the Operating Standards for NOAA Hyperbaric Chambers:

“20-7.8.3 Use of Diving Medical Officer as Inside Tender. If only one Diving Medical Officer is on site, the Medical Officer should lock in and out as the patient's condition dictates, but should not commit to the entire treatment unless absolutely necessary. Once committed to remain in the chamber, the Diving Medical Officer effectiveness in directing the treatment is greatly diminished and consultation with other medical personnel becomes more difficult. If periods in the chamber are necessary, visits should be kept within no-decompression limits if possible.”

While some practices may vary in design, we suggest that you consider the many primary duties of the supervising Hyperbaric Provider that may exist outside of the chamber. This individual is normally relied upon to provide consultative services, complete therapy documentation, communicate with referring providers, and provide direction in the event of a facility or in-chamber emergency. It is our view that these primary supervision and management responsibilities are best performed when the provider is not encumbered by delivering direct patient care inside of the chamber.

It is also our view that the supervising Hyperbaric Provider remain aware of events occurring outside of the chamber in order to provide global direction, and must be able to do so without being exposed to the physiologic risk factors caused by hyperbaric exposure (barotrauma, nitrogen narcosis, risk of breathing oxygen during decompression, DCI). Furthermore, the UHMS Guidelines for Hyperbaric Facility Operations, 2^nd edition calls for the supervising Hyperbaric Provider to be “readily available during treatments”. We suggest that if there are other chamber operations occurring within the clinic, a provider who is serving as an inside attendant will not be able to properly supervise these operations simultaneously.

Reported prevalence in the hyperbaric community:

While this practice is not considered common in the hyperbaric community, the committee is aware of a handful of hyperbaric practices that will occasionally utilize the lone provider as an attendant in the chamber for special situations. Consider these statements from members of the Hyperbaric Safety Committee:

• Done only in extreme cases where there is no alternative attendant and there is an emergency need to treat a critical care patient.
• Only when there is another trained hyperbaric provider on-site and standing by.
• Only when there is a trained individual qualified by the medical director to manage the chamber in an emergency. If such a person is not available, then the physician should not enter the chamber except in a dire emergency (life-or-death event).
• May occur in the treatment of DCS or AGE where a neurologic assessment by the physician is needed. In many cases a trained fellow is utilized instead of exposing the supervising hyperbaric provider.
• The physician should be able to lock in, but not for any reason other than a medical emergency or complication.
• Occurs when treating a patient using a TT6 or TT6a or COMEX, and dependent upon staffing and the time of night/day - the physician will enter the chamber when the tender goes on oxygen at the end of the table. In these cases, there are no elective treatments scheduled after this exposure.

In closing, we encourage administrators and program managers responsible for the safety of their hyperbaric programs to consider the standards and recommendations we have listed here and allow staffing decisions such as these to be made jointly by the HMD and HSD of the hyperbaric program. We also suggest that the HMD and HSD conduct a formal Risk Assessment that is inclusive of the factors mentioned above prior to developing a staffing policy for the program. We understand that there may be many other considerations not mentioned here that are unique to your facility and should be included within the risk assessment.

Respectfully,

The UHMS HBO2 Safety Committee

REFERENCES:

Burman, F. (2019). Risk Assessment Guide for Installation and Operation of Clinical Hyperbaric Facilities (6th ed.). San Antonio, TX: International ATMO, Inc.

National Fire Protection Agency (NFPA). (2021). NFPA 99 2021 Edition: Health Care Facilities Code. Quincy, Massachusetts.

National Oceanic and Atmospheric Administration (NOAA). Operating Standards for NOAA Hyperbaric Chambers (2017) NOAA.gov

Naval Sea Systems Command. (2016). US Navy Diving Manual (7th ed.). United States Navy Publication.

Workman, W. T. (2015). Guidelines for Hyperbaric Facility Operations. 2^nd Ed. Best Publishing Company. Section 2: Job Descriptions and Responsibilities, I. Hyperbaric Medicine Physician and Section. 3: Staffing Guidelines, I.: Physician/NPP Staffing

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

Currently treating a cancer patient who smokes marijuana for pain control. We coached him not to smoke prior to treatments but I'm having trouble finding any studies or recommendations regarding safety.

Poste: 11/01/21

Q: 
Currently treating a cancer patient who smokes marijuana for pain control. We coached him not to smoke prior to treatments but I'm having trouble finding any studies or recommendations regarding safety.

A:

Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Hyperbaric Medical Director (HMD) and Hyperbaric Safety Director (HSD) of your facility.

We would advise that the HMD review the literature on cannabis use and consider the potential for adverse effects when used in conjunction with Hyperbaric Oxygen Therapy. Specifically, the Committee has viewed reports that increased risk of hemoptysis and pneumothorax to heavy users of inhaled cannabis users (see references below).

If the decision is made to treat, we would recommend that a standard pre-dive assessment by the RN/MD team is done. In the chronic or elective setting, it is important to ensure that the patient can follow commands, isn’t experiencing paranoia, confusion, or claustrophobia. It is important to make the patient aware ahead of time that for their safety and the safety of those in the chamber, the physician may determine that it isn’t safe to treat them if these conditions are present.

In the acute setting there could be cases where the mentation of the patient may be less important (e.g. carbon monoxide poisoning, AGE, etc.).

We would also recommend that an approach similar to that of cigarette use is taken. We recommend that you implement heighted precautions related to the presence of heat sources and increase the awareness of your care team. Some facilities discourage their wound care patients from smoking due to the impact of increased vasoconstriction. You may also wish to consider offering the patient other non-smoking options in order to limit some of the risk.

The UHMS HBO2 Safety Committee identifies that although there is potential for increased risk, the decision to treat rests solely on the HMD and the team providing care. The HSD should also be included in the decision-making process.

Respectfully,

The UHMS HBO2 Safety Committee

REFERENCES:

1. Manasrah, N., Al Sbihi, A. F., Al Qasem, S., Naik, R., & Hettiarachchi, M. (2021). Recurrent Spontaneous Pneumothorax Associated With Marijuana Abuse: Case Report and Literature Review. Cureus, 13(2). https://doi.org/10.7759/cureus.13205
2. Massey, M., & Barney, J. (2021). Pulmonary actinomycosis and marijuana vaping. BMJ Case Reports CP, 14(4), e240973. https://casereports.bmj.com/content/14/4/e240973.abstract
3. McGraw, M. D., Houser, G. H., Galambos, C., Wartchow, E. P., Stillwell, P. C., & Weinman, J. P. (2018). Marijuana medusa: The many pulmonary faces of marijuana inhalation in adolescent males. Pediatric pulmonology, 53(12), 1619-1626. https://doi.org/10.1002/ppul.24171
4. Oh, J. S., Wong, U., Bajaj, D., & Hines, S. E. (2020). Isolated pauci-immune pulmonary capillaritis associated with hydrocarbon inhalation and marijuana smoking: an unusual case of severe hypoxemia. Case reports in pulmonology, 2020. https://doi.org/10.1155/2020/1264859
5. Singh, A., Tan, Q., Saccone, N. M., & Lindner, D. H. (2020). A case of vaping TCH oil leading to vaping associated pulmonary injury: our approach to its diagnosis, management, and recommendations. Case reports in pulmonology, 2020. https://doi:10.1155/2020/6138083
6. Stone, T., Henkle, J., & Prakash, V. (2019). Pulmonary mucormycosis associated with medical marijuana use. Respiratory medicine case reports, 26, 176-179. https://doi:10.1016/j.rmcr.2019.01.008

7.       Tan, W. C., Bourbeau, J., Aaron, S. D., Hogg, J. C., Maltais, F., Hernandez, P., ... & Sin, D. D. (2019). The effects of marijuana smoking on lung function in older people. European Respiratory Journal, 54(6). https://doi:10.1183/13993003.00826-2019

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

Do you know of any article of anything that gives guidelines for defibrillation in the HBO suite (monoplace)? In other words, during cardiac arrest in a monoplace chamber, are there guidelines that describe getting the patient out of the monoplace chamber and how far away from the chamber / or out of the suite to defibrillate (required distance from the chamber before defibrillation).

Posted: 11/15/21

Q:
Do you know of any article of anything that gives guidelines for defibrillation in the HBO suite (monoplace)?  In other words, during cardiac arrest in a monoplace chamber, are there guidelines that describe getting the patient out of the monoplace chamber and how far away from the chamber / or out of the suite to defibrillate (required distance from the chamber before defibrillation).

A:
Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Hyperbaric Medical Director (HMD) and Hyperbaric Safety Director (HSD) of your facility.

The UHMS HBO₂ Safety Committee is aware of several publications that may be able to assist you in your decision-making on how to approach the defibrillation of a patient immediately following hyperbaric oxygen therapy in a monoplace chamber. For your convenience, we will provide excerpts from these publications:

• "Hyperbaric Medicine Procedures" published by St. Luke's Medical Center, Milwaukee, WI. 1995 Edition, page 80. DEFIBRILLATION MUST NEVER BE ATTEMPTED INSIDE AN OXYGEN FILLED MONOPLACE CHAMBER. Prior to defibrillation the patient must be brought to surface and removed from the chamber and preferably from the immediate area.  When the chamber door is opened, oxygen will spill into the room making defibrillation especially hazardous for the first 30 seconds.  The fabric of patient gowns and bedclothes will remain saturated with oxygen when removed from the chamber and needs to be stripped from the patient before attempting defibrillation.
• "Hyperbaric Medicine Procedures" published by St. Luke's Medical Center, Milwaukee, WI. 2006 Edition, page 108. DEFIBRILLATION MUST NEVER BE ATTEMPTED INSIDE AN OXYGEN FILLED MONOPLACE CHAMBER. Prior to defibrillation the patient must be brought to surface and removed from the chamber and preferably from the immediate area.   When the monoplace chamber door is opened, oxygen will spill into the room and immediately fall to the floor as it is quite cold and heavier than room air.  We have done experiments to measure oxygen in the atmosphere at various locations in the room after opening the chamber door following an emergency decompression and found that the levels return to baseline within 30 seconds.  Simply removing the sheets and blankets from the gurney will render the defibrillation safe.
• "Hyperbaric Medicine Practice". L Weaver, page 249. I have defibrillated one patient and cardioverted another patient who were rapidly removed from the monoplace chamber for dysrhythmias, both successfully. Some hyperbaric practitioners have recommended that patients exiting the oxygen-filled chamber be moved some distance away from the chamber prior to defibrillation, because of concerns about the risk of combustion. The patient's tissues (including the brain and heart) presumably will have high concentrations of O2, so taking a few extra seconds to move the patient to an area with a lower ambient concentration of O2 should be acceptable.  In the two cases commented upon above, a few seconds elapsed following extraction of the patients from the chamber before defibrillation.  Both patients were defibrillated/cardioverted while on the gurney attached to the monoplace chamber.  There was no evidence of sparks or fire.  Provision for cardiac monitoring, defibrillation, bag-valve-mask ventilation, and intubation must be readily available if the hyperbaric unit anticipates treating critically ill patients.  (Editor's note: We have measured oxygen levels in the room after emergency decompressing and opening a monoplace chamber.  The cold oxygen falls to the floor and dissipates in about 30 seconds.  It does not measurably remain elevated at the level of the patient or rise in other parts of the room.
• “Critical care of patients needing hyperbaric oxygen therapy” In: Physiology and Medicine of Hyperbaric Oxygen Therapy (Neuman, T.S., Thom, S.R.), page 124. Weaver, L. (2008). Defibrillation and cardioversion. For monoplace chamber patients who need defibrillation or cardioversion, these procedures must be done outside the chamber. It is advisable to switch gas supply from oxygen to air while decompressing these patients to hasten dissipation of oxygen from around the hyperbaric chamber door. Patients are cardioverted or defibrillated after opening the chamber hatch and sliding the patient out of the chamber onto the gurney. If switching the chamber gas supply to air is not possible, then 40 seconds or more needs to elapse for oxygen to dissipate before defibrillation. Also, all patient garments must be removed before defibrillation because they, too, will be oxygen enriched and thus increase the risk for fire.

Several other UHMS HBO₂ Safety Committee members have offered their experience on this topic. You may find these comments helpful as you decide how to proceed:

• “From all my discussions on this, the consensus these days is to defibrillate outside of the chamber after a rapid decompression to the surface. You would move the patient onto another bed (or remove the bedding) approximately 6 feet from the chamber door. You’d need to remove the upper clothing to reveal the chest. There is very little risk of ignition, as the spark duration is very short, even if repeated.”
• “We do not remove the patient from the gurney or remove the sheet. We remove all other bedding and use contact gel on the pads to mitigate the risk of ignition.”
• “I have personally attempted to ignite patient gown material, 100% cotton, that was hyperbarically oxygen saturated and the same gown material without the hyperbaric oxygen saturation. The hyperbaric oxygen saturated material ignited much easier and burned more vigorously than the cotton sample from ambient room air. This test was not quantified or published.”
• “Our practice would be to move them from the monoplace room to an adjacent procedure room. We would remove clothing and sheets - transferring the patient to a bare cart, leaving linens behind. We’ve practiced this and the whole process takes less than a minute.”
• “Our practice follows the regimen outlined by Dr. L Weaver in “Hyperbaric Medicine Practice".”

Respectfully,

The UHMS HBO₂ Safety Committee

REFERENCES:

1. Kindwall, E. P., & Goldmann, R. W. (1995). Hyperbaric medicine procedures. Department of Hyperbaric Medicine, St. Luke's Medical Center.
2. Kindwall, E. P., & Niezgoda, J. A. (2006). Hyperbaric medicine procedures. Department of Hyperbaric Medicine, St. Luke's Medical Center.
3. Weaver, L. K. (1995). Management of critically ill patients in the monoplace hyperbaric chamber, Hyperbaric Medicine Practice. Edited by Kindwall EP. Flagstaff.
4. Weaver, L. (2008). Critical care of patients needing hyperbaric oxygen therapy. In: “Physiology and Medicine of Hyperbaric Oxygen Therapy”, Neuman, T.S., Thom, S.R., pg. 124.

Additional resourses: 

• To shock or not to shock: How big an issue is it?  A study of the prevalence of defibrillators and associated incidents inside clinical hyperbaric chambers.
  Lee Griffiths, University of Hull

 DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

With increased use in both recreational/medical marijuana, are there recommendations or concerns with vaping or smoking of marijuana and HBO therapy? A recent you tube video lesson states increase in ground glass opacities with vaping/smoking marijuana.

Posted:7/13/2022

Q:
With increased use in both recreational/medical marijuana, are there recommendations or concerns with vaping or smoking of marijuana and HBO therapy? A recent you tube video lesson states increase in ground glass opacities with vaping/smoking marijuana.

A:

Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Hyperbaric Medical Director (HMD) and Hyperbaric Safety Director (HSD) of your facility.

The proliferation of legalized cannabis use in the United States has increased utilization of cannabis¹⁵, potency of available product, and diversified intake methods.  Coinciding with this increased use is improved awareness of adverse effects including the development of ground-glass opacity (GGO)^1,3,9 , pulmonary inflammation^3,7, hemoptysis³, pneumothorax⁷, opportunistic pulmonary infection⁸, and Cannabis Withdrawal Syndrome (CWS)².

       The most common causes of pulmonary GGO on CXR or CT chest scan were historically most prevalent with carcinoma but had also been seen with amiodarone lung and invasive pulmonary infections¹⁴.  More recently, incidence has been higher for COVID-19 and vaping history¹⁴.  While the other disorders are generally associated with a compromised individual questioned for treatment risk/benefit of hyperbaric exposure in diving or hyperbaric oxygen (HBO), vaping individuals may otherwise appear healthy, and their vaping history may not be known.  Where it has been studied, there is a stratification of risk with vaping being worse than traditional smoking (e.g., joints, cigarettes, hookah) and vaping cannabis being notably worse in generating pathology than vaping tobacco or flavored mist⁴.  Chronic cannabis users by any method may develop a functional intoxication masking their use such that usual screening for a “high” might fail and not all serum studies sample for long-acting THC metabolites^10,13,15, even including government testing^{11, 12}.

       The cases reporting has increased notably within the last two years.  In cases reporting pathology, pulmonary inflammation appears to be instigated by pulmonary interstitial aluminum silicate crystal formation leading to structural tissue weakening^7,9.  The best objective risk factor for pulmonary barotrauma appears to be chest CT^{1, 4, 5}.  CXR may be a sufficient screening tool, however this exam can miss GGO in certain circumstances¹.

       The pulmonary risk associated with cannabis appears limited to inhaled uses.  No literature was found associating this risk with topical or edible cannabis using the search terms cannabis, diving, and hyperbaric in the Pubmed, CINAHL, Google Scholar, and UCCS Kraemer Family Library OneSearch databases.  Youth and limited usage did not appear to be mitigating with cases reported as young as 15 years⁹ and usage as little as one joint⁹, although prevalence does appear to increase with frequency of use⁴.  Pulmonary pathology was reported at ambient pressure^7,8,9 and as shallow as 9 feet seawater³.  The available evidence has not stratified pressure method for increased risk of one over another (i.e., HBO, breath-hold, SCUBA, aerospace, etc.).

The bottom line: Ensure a complete social history during fitness to dive, aerospace, and hyperbaric oxygen consultations.  Consider a low threshold for CXR or chest CT screening where an inhaled cannabis use is reported.

REFERENCES:

1. Bell, D. J. (2021, October 30). Ground-glass opacification: Radiology reference article. Radiopaedia Blog RSS. Retrieved March 22, 2022, from LINK
2. Bonnet, U., & Preuss, U. W. (2017). The cannabis withdrawal syndrome: current insights. Substance abuse and rehabilitation, 8, 9–37. LINK
3. Borg, J., Cassar, J., Bonello, S., & Fsadni, P. (2020, June 9). Haemoptysis following shallow breath-hold diving in a cannabis user. British Medical Journal Case Report, 13(e234921). LINK
4. Hammond, D. (2019, September 10). Outbreak of pulmonary diseases linked to vaping. British Medical Journal, 366(l5445). LINK
5. Kennedy, J, & Leikin, J. (2020). Pulmonary disease related to E-cigarette use. New England Journal of Medicine, 383(8). 792-793. LINK
6. Li, X., Ren, F., Wang, S., He, Z., Song, Z., Chen, J., & Xu, S. (2020). The Epidemiology of Ground Glass Opacity Lung Adenocarcinoma: A Network-Based Cumulative Meta-Analysis. Frontiers in oncology, 10(1059). LINK
7. Manasrah, N., Al Sbihi, A. F., Al Qasem, S., Naik, R., & Hettiarachchi, M. (2021, February 7). Recurrent spontaneous pneumothorax associated with marijuana abuse: Case report and literature review. Cureus, 13(2), e13205. LINK
8. Massey, M., & Barney, J. (2021). Pulmonary actinomycosis and marijuana vaping. BMJ Case Report 2021, 14(E240973). doi:10.1136/bcr-2020-240973. LINK
9. McGraw, M.D., Houser, G.H., Galambos, C., Wartchow, E.P., Stillwell, P.C., & Weinman, J.P. (2018). Marijuana medusa: The many pulmonary faces of marijuana inhalation in adolescent males. Pediatric Pulmonology, 2018(53):1619–1626. LINK
10. Meintjes, J. (2019, August 1). Cannabis & diving: Revisiting dive safety after legalization. AlertDiver.com. LINK
11. National Highways Traffic Safety Administration (2017, July). Marijuana-impaired driving: A report to congress. DOT HS 812 440. U.S. Department of Transportation, National Highway Traffic Safety Administration. LINK
12. State of Colorado (2022). Driving and traveling. Colorado Cannabis. [website]. LINK.
13. Toth, H., Mann, C., & Parsh, B. (2002, May). Recognizing acute cannabis intoxication. Nursing2022, 52(5) 10-11. LINK
14. Van Haren, R. M., Correa, A. M., Sepesi, B., Rice, D. C., Hofstetter, W. L., Mehran, R. J., Vaporciyan, A. A., Walsh, G. L., Roth, J. A., Swisher, S. G., & Antonoff, M. B. (2019). Ground glass lesions on chest imaging: Evaluation of reported incidence in cancer patients using natural language processing. The Annals of Thoracic Surgery, 107(3), 936-940. LINK
15. Viders, H. (2016). Marijuana and diving. AlertDiver.com. LINK

Respectfully,

The UHMS HBO₂ Safety Committee

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

Is it acceptable to use aviation grade oxygen for in-water oxygen decompression, SurDO2, and hyperbaric treatment?

Posted: 7/13/2022

Q:

Is it acceptable to use aviation grade oxygen for in-water oxygen decompression, SurDO2, and hyperbaric treatment?

A:

Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Hyperbaric Medical Director (HMD) and Hyperbaric Safety Director (HSD) of your facility.

This is a known challenge for many companies performing in-water diving operations. Apart from requiring oxygen for filling rebreather cylinders, making up nitrox and technical mixtures, and preparing for in-water decompression (enriched mixtures and pure oxygen), it may be difficult to receive permission from industrial gas companies to fill emergency oxygen cylinders where this is administered by the lay person. At least one major industrial gas company has issued a memo to this extent and will fill cylinders without a physician’s prescription, on the basis that it is not used for any medical treatments.

The committee understands that in your situation, a physician is on-call to provide oversight of hyperbaric therapy operations, should the need arise. We suggest that, if it is in the best interest of the patient (injured diver), and your Medical Director (physician-in-charge, Diving Medical Officer, etc.) chooses to utilize Aviator’s Breathing Oxygen (ABO) in an off-label capacity, it is their right to do so under the FDA’s Off-Label Use of Drugs and Devices. You may wish to develop a company policy to this effect, ensuring that all physicians who are responsible for supervising therapy are comfortable with this approach.

Regarding the safety of Aviator’s Breathing Oxygen, it should be known that ABO is specifically intended for breathing and is analyzed more thoroughly than medical oxygen. Aviation grade oxygen is analyzed for more  potentially harmful elements and is generally drier. From a manufacturing standpoint, all oxygen is usually made from the same production source. The main differences between the gases are the requirements for certification through analysis. CGA G-4.3 (2018) is the standard that contains the allowable limits for impurities for oxygen in its various forms.

In short, it does not appear that there would be any therapeutic differences between the use of Medical Grade oxygen used for clinical applications, and ABO. We would encourage you to consult with the Medical Leadership, Safety Personnel, and Administrative partners within your company to make this decision. Furthermore, we encourage you to develop the documentation, staff awareness, education and documentation necessary to satisfy any perceived legal, liability or safety concerns you may have.

REFERENCES:

1. Burman, F. (2019). Risk Assessment Guide for Installation and Operation of Clinical Hyperbaric Facilities (6th ed.). San Antonio, TX: International ATMO, Inc.
2. CGA G 4.3: 2018 Commodity Specification for Oxygen, 7th edition, Compressed Gas Association LINK
3. Department of Defense, “PERFORMANCE SPECIFICATION OXYGEN, AVIATOR’S BREATHING, LIQUID AND GAS, (MIL-PRF-27210J),” (08/2013) LINK
4. US Food and Drug Administration. (2014). “Off-label” and investigational use of marketed drugs, biologics, and medical devices: information sheet. Silver Spring, MD. LINK

Respectfully,

The UHMS HBO₂ Safety Committee

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

Is there any contraindication to treating a patient with a subarachnoid hematoma stable over two CTH scans 12 hours apart and felt stable for home discharge by neurosurgery?

Posted: 8/26/22

Q: 
Is there any contraindication to treating a patient with a subarachnoid  hematoma stable over two CTH scans 12 hours apart and felt stable for home discharge by neurosurgery?

A:
The chair of the HBO2 Committee responded that there should not be any risk to this patient if treated with hyperbaric oxygen therapy. The SAH is a fluid-filled space and should not undergo any pressure-related changes. 

I work in a Hospital with two monoplace chambers. We are going to be running a 10-month old infant for hyperbaric treatment related to Hypospadias. Can the infant bring in a bottle with milk and/or pacifier? What about teething ring or soft toys? Can the infant wear a diaper with the Velcro removed and tape placed?

Posted: 9/6/2022

Q:  

I work in a Hospital with two monoplace chambers. We are going to be running a 10-month old infant for hyperbaric treatment related to Hypospadias. Can the infant bring in a bottle with milk and/or pacifier? What about teething ring or soft toys? Can the infant wear a diaper with the Velcro removed and tape placed?

 A:

Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Hyperbaric Medical Director (HMD) and Hyperbaric Safety Director (HSD) of your facility.

Regarding the items considered for allowance in the monoplace environment, the UHMS HBO₂ Safety Committee cannot approve a particular item for use in the chamber. We would offer the following suggestions:

Bottle filled with milk – Consider that the bottle will have to be properly ventilated. Evaluate if the opening on the tip is wide enough to vent the air space within the bottle.

Pacifier –  Consider that Boyle’s law will also have an impact on the size of the rubber bulb. Otherwise, this should not pose a significant risk. We would encourage you to pay attention to items that may fall between the gurney and the rails. Any loose item in the chamber can cause an obstacle upon removal of the patient. This may also lead to damage to the acrylic.

Teething Ring and soft toys – See note above on loose items. You should evaluate these items for potential risk to generate static, but the risk is likely to be minimal. Ensure that the patient and the chamber is properly grounded.

Diapers – Please refer to the UHMS HBO₂ Safety Committee’s previous answer on this topic. LINK

Your approach to the care of the infant during hyperbaric oxygen therapy is dependent upon the assessment of risk by your HMD and HSD. Several hyperbaric facilities have treated infants safely in the Monoplace Chamber. Some have assessed, and local policy dictates, that it is unsafe to leave an infant unattended and have applied the FDA’s provision to perform therapy under Off-Label practices, while under the supervision of a Physician and subject to certain, safety-based criteria. Others have adhered to the classification of the chamber occupancy and determined that the risk to the infant is greater with an occupant caregiver. The UHMS HBO2 Safety Committee does not support one decision over the other. We would suggest that you evaluate several factors prior to making this decision for your facility:

Considerations when treating an infant with an occupant caregiver in the monoplace setting:

• Please refer to the UHMS HBO2 Safety Committee’s previous answer on this topic. LINK

Considerations if treating an infant without an occupant caregiver in the monoplace setting:

There are several factors that may lead to this decision:

• Consider that the NFPA, the FDA, and the chamber manufacturer have recognized monoplace chambers as single occupancy.
• There is no interest by the HMD to authorize the off-label use of the medical device and assume the potential liability.
• The HMD and HSD deems that placing another individual inside the chamber will create unnecessary risk to both occupants by way of smothering caused by seizure or theoretical DCS risk if wrong gas is delivered.

When treating an infant/pediatric patient in the monoplace, consider the following:

• Consider the opportunity for ECG monitoring of this patient during therapy. Consider adding this capability to your chamber.
• Keep the stretcher in the flat position. Place hyperbaric-approved blankets surrounding the patient to prevent injury by rolling off.
• Offer the presence of a Neonatal Intensive Care (NICU) Nurse throughout therapy. Observe for signs of bradycardia and airway issues.
• Address the need for Pressure Equalization tubes. Older pediatric patients may not require this procedure if they are able to perform equalization techniques effectively.
• The presence of parents in the treatment room may be helpful in assuring that the patient is comfortable and safe.

REFERENCES:

Celebi, A. R. C., Kadayifcilar, S., & Eldem, B. (2015). Hyperbaric oxygen therapy in branch retinal artery occlusion in a 15-year-old boy with methylenetetrahydrofolate reductase mutation. Case reports in ophthalmological medicine, 2015.

Fok, T. F., Shing, M. K., So, L. Y., & Leung, R. K. W. (1990). Vascular Air Embolism‐Possible Survival. Acta Pædiatrica, 79(8‐9), 856-859.

Hsieh, W. S., Yang, P. H., Chao, H. C., & Lai, J. Y. (1999). Neonatal necrotizing fasciitis: a report of three cases and review of the literature. Pediatrics, 103(4), e53-e53.

Korambayil, P. M., Ambookan, P. V., Abraham, S. V., & Ambalakat, A. (2015). A multidisciplinary approach with hyperbaric oxygen therapy improve outcome in snake bite injuries. Toxicology International, 22(1), 104.

Liebelt, E. L. (1999). Hyperbaric oxygen therapy in childhood carbon monoxide poisoning. Current opinion in pediatrics, 11(3), 259-264.

Mader, J. T., Adams, K. R., Wallace, W. R., & Calhoun, J. H. (1990). Hyperbaric oxygen as adjunctive therapy for osteomyelitis. Infectious disease clinics of North America, 4(3), 433-440.

Marosek, N. J., (2019) Optimizing the pediatric hyperbaric oxygen therapy plan: Tandem therapy. UHMS Safety Pre-Course presentation.

Smith-Slatas, C. L., Bourque, M., & Salazar, J. C. (2006). Clostridium septicum infections in children: a case report and review of the literature. Pediatrics, 117(4), e796-e805.

Tsung, J. W., Chou, K. J., Martinez, C., Tyrrell, J., & Touger, M. (2005). An adolescent scuba diver with 2 episodes of diving-related injuries requiring hyperbaric oxygen recompression therapy: a case report with medical considerations for child and adolescent scuba divers. Pediatric emergency care, 21(10), 681-686.

Waisman, D., Shupak, A., Weisz, G., & Melamed, Y. (1998). Hyperbaric oxygen therapy in the pediatric patient: the experience of the Israel Naval Medical Institute. Pediatrics, 102(5), e53-e53.

Respectfully,

The UHMS HBO₂ Safety Committee

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

What are the current recommendations for activity restrictions (i.e. strenuous exercise), for inside attendants following a hyperbaric exposure (treatment)? Our standard profiles are 2.0ATA/ 105 minutes ABT, 2.4ATA/ 90 minutes ABT, 2.8ATA/ 85 min ABT, TT5, TT6, and 3.0ATA/ 85 min ABT

Posted: 9/19/22

Q: 

What are the current recommendations for activity restrictions (i.e. strenuous exercise), for inside attendants following a hyperbaric exposure (treatment)? Our standard profiles are 2.0ATA/ 105 minutes ABT, 2.4ATA/ 90 minutes ABT, 2.8ATA/ 85 min ABT, TT5, TT6, and 3.0ATA/ 85 min ABT.

A: 

Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Hyperbaric Medical Director (HMD) and Hyperbaric Safety Director (HSD) of your facility.

The UHMS HBO2 Safety Committee is aware of several programs which have instituted guidelines for inside attendants following a hyperbaric exposure. Unfortunately, there is no clear-cut answer to this question, but there are several references to consider. The safety committee will also offer the following comments from its members and our colleagues:

• In our department we have not set strict time limits.  We recommend using good judgment based on your normal workout history, with a 2–4-hour pre/post rest period as a baseline.  If you decide to work out, with a heavier than normal exercise regimen, your pre/post hyperbaric exposure time should be lengthened.
• Guideline information is shared and taught with all HBO staff, but we do not have a firm policy on this. For exceptional dives such as 5, 6, and 6A, they are given post-dive instructions. One item within the instructions expresses that they should avoid heavy activity for the next eight hours. But in all honesty, the practice of not exercising 4-6 hours pre or post dive has always been difficult to follow, especially for active tenders (regarding daily TT9 dives) as this would consume most of the day.
• A strict policy on exercise after compressed air exposure is problematic for several reasons. The recommendations used in our facility is listed below. I am not aware of published incident(s). Could this be a theoretical risk?

1.1.    NO STRENUOUS and/or JARRING EXERCISE AND NO COMPRESSED GAS DIVING:

1.1.1. Within 16 hours of completion of a single hyperbaric chamber pressurization.

1.1.2. Within 24 hours of completion of the last of multiple exposures (in one day) or single exposures over multiple days.

1.1.3. Within 48 hours of completion of an USN table 6 or any decompression profile with a USN group Z

Any deviation from this should be discussed beforehand (or as soon after as possible) with the Hyperbaric Medicine Staff physician. If there are any possible signs/symptoms of decompression sickness the Hyperbaric Medicine Staff Physician should be contacted as soon as possible.

• Matias Nochetto, MD “I don’t know any widely accepted standard recommendation for divers, and I am not aware of any for Inside Attendants. Common sense suggests that strenuous physical activity during decompression phase is not desirable. Where is the line to say it is ok is hard to answer; and a solid evidence-based answer might require a long and expensive research endeavor. The decompression stress imposed to an inside attendant tending treatments ranging from 2.0 ATA / 105 min to a fully extended USNTT6 is quite different. On the lighter ones (wound healing ones), I think it is reasonable to assume that for all practical purposes there is no more residual nitrogen after 12 hours. Moderate physical activity is probably acceptable long before that, but I don’t know of any tools to help us determine where that line is. Six hours? Four? I don’t know. Now if we talk about strenuous exercise, then I would recommend a longer interval. For those treatments imposing the highest decompression stress, I would definitively recommend no less than 12 hours and possibly more, like 18 or 24. Anything over 24 I think it is probably unnecessary. But one must consider that strenuous physical activity can take a big toll even on trained athletes, and any symptoms following exercise that followed a dive could represent a diagnostic challenge. Although a strenuous physical activity following a dive is not necessarily the same physiological insult as a hypobaric exposure following a dive, one could look at the Flying After Diving guidelines as a reference for a sensible approach. After all, the real question is how long should I wait to have a significant inert gas elimination to not be concerned about bubble formation when I add another stressor.”
• From Doc Vikingo, 03/2004: “The best advice is moderation. Stay well hydrated and warm. Avoid strenuous exercise of any type for 4 and 6 hours before and after diving, respectively, but remain mildly active between dives and for a while after the last dive.”

Exercise Before, During, and After Diving: Undercurrent 03/2004

• Madden, D., Lozo, M., Dujic, Z., & Ljubkovic, M. (2013): Recent studies have demonstrated the right-to-left passage of bubbles through intrapulmonary arterial-venous anastamoses (IPAVA) that allow blood to bypass the pulmonary microcirculation. These passages open up during exercise, and the aim of this study is to see if exercise in a postdiving period increases the incidence of arterialization….The safety of exercise after diving has been debated for some time. We have shown that exercise may directly contribute to arterialization. It may be concluded that exercise directly increases vulnerability to arterialization of VGE after diving. In some individuals, specifically those who have a low workload threshold for opening of IPAVA, it is possible that even relatively mild physical exertion associated with surface swimming at the end of a dive, climbing onto a boat, or walking with heavy gear on would be enough to provoke arterialization……Although many studies have shown that divers can arterialize with no DCS symptoms, there still remains a correlation between neurological DCS and the presence of arterial bubbles. Finally, subclinical levels of damage related to microemboli in the brain should not be ignored, especially in career divers.”

Exercise after SCUBA diving increases the incidence of arterial gas embolism | Journal of Applied Physiology

• “In general, the consensus amongst researchers is that exercise should be avoided within four to six hours before and after diving. Previously, this was set at 24 hours which was impractical.”

https://www.dansa.org/blog/2017/08/25/physical-exercise-before-during-after-a-dive

• Dr. Ernest Campbell: “If one were to put four restful hours between exercise and diving and six between diving and exercise, a diver should be in good shape in terms of absent bubbles.”

http://www.awoosh.com/DocVikingo/Exercise_and_DCS.htm

Based upon these responses, there does not seem to be a consensus agreement among the diving and hyperbaric community on this subject. The UHMS HBO2 Safety Committee recommends a local review of the literature among the Hyperbaric Medical Director (HMD) and Hyperbaric Safety Director (HSD) to determine the best course of action for your facility. Please keep in mind that any changes in your approach should be shared and documented with your hyperbaric team.

REFERENCES:

1. Burman, F. (2019). Risk Assessment Guide for Installation and Operation of Clinical Hyperbaric Facilities (6th ed.). San Antonio, TX: International ATMO, Inc.
2. DAN South Africa (08/25/2017), Article: “Physical Exercise Before, During & After A Dive,” Accessed 9/12/2022.
3. Doc Vikingo Diver’s Resource (2004), Article: “Exercise and Diving: When is it a Good Thing?” Accessed 9/12/2022.
4. Doc Vikingo – Undercurrent Online (03/2004), Article: “Exercise Before, During, and After Diving,” Accessed 9/12/2022.
5. Madden, D., Lozo, M., Dujic, Z., & Ljubkovic, M. (2013). “Exercise after SCUBA diving increases the incidence of arterial gas embolism.” Journal of Applied Physiology, 115(5), 716-722.
6. Workman, W. T., & Wood, J. S. (2020). Hyperbaric Facility Safety: A Practical Guide (2nd ed.). Best Publishing Company.

Respectfully,

The UHMS HBO₂ Safety Committee

 DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

This practitioner called this AM asking about our thoughts on a patient in the monoplace chamber who was observed having static electricity buildup (hair was standing up during the treatment) despite the patient being grounded. They did stop the treatment and pulled the patient out of the chamber and tested all the spots recommended for the ohm's test and all were in range. Humidity is in the 40% range. They called Sechrist and all was as it should be, and this person is calling about what we know about i

Posted: 10/25/2022

Q:
This practitioner called this AM asking about our thoughts on a patient in the monoplace chamber who was observed having static electricity buildup (hair was standing up during the treatment) despite the patient being grounded. They did stop the treatment and pulled the patient out of the chamber and tested all the spots recommended for the ohm's test and all were in range. Humidity is in the 40% range. They called Sechrist and all was as it should be, and this person is calling about what we know about it and make any necessary recommendations.

A:

Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Hyperbaric Medical Director (HMD) and Hyperbaric Safety Director (HSD) of your facility.

The Committee understands your concern for patient safety, which should always be in the forefront of our minds as clinicians in the field of hyperbaric medicine. It is right and proper to ensure that the chamber and patient remain grounded. However, the situation you describe has occurred numerous times when certain conditions have been met, and there is a simple remedy that can be applied.

Medical-grade oxygen is generally a very dry gas. As humidity is the main factor in static generation, decreased humidity coupled with gas flow can cause an imbalance of electrons within the chamber. As dry gas flows along the cylindrical walls of the chamber, unbalanced electrons that surround very light objects can be drawn outward, and thus cause hair to “float” or “stand up”.

The Committee recommends the following actions if this phenomenon occurs:

1. a) Spray and wipe the acrylic (interior and exterior) with Novus^© 1 Plastic Clean & Shine.
2. b) Spritz the patient’s hair with clean water.

More information on static in the hyperbaric environment:

• The subject of static generation is one that should be understood well by operators of hyperbaric chambers. This topic was highlighted during the UHMS Scientific Meeting Safety Pre-Course in 2017. A third-party electrical engineering specialist, skilled in testing materials in oxygen-enriched environments was invited to be part of the panel. You may wish to review the entire content of their presentation here. The group expressed the following conclusions, (from slide #20):

The analysis of risk factors and associated data as a group suggests that the risk is mitigated in current HBO applications.

(This is) Supported by the successful history of use when implementing the current standard of safety. (e.g., NFPA 99, grounding straps, cleanliness, etc.)

• Another wonderful resource that may help you to better understand the factors surrounding static in the monoplace hyperbaric chamber is found in Sheffield and Burman’s article: “Static Electricity and Grounding in Hyperbaric Chambers.” We would encourage you to read through this article and take advantage of the 1 ‘Category A’ Continuing Education Credit offered by the NBDHMT through International ATMO.
• Some facilities have looked to add a humidifier to the room housing the chambers. However, as soon as the chamber door is closed, dry oxygen fills the cylinder. Humidity is likely to decrease throughout the treatment, so this solution may have limited effect. There is no code requirement for a humidifier in the room housing the chambers. The UHMS HBO2 Safety Committee responded to a question on this topic in 2015. LINK
• NFPA 77: Recommended Practice on Static Electricity (2019) is another pertinent resource that may offer valuable information on this topic. Of note, NFPA 77 has this to say regarding the application of humidity:

7.4 Charge Dissipation

7.4.2.3 - Humidification is not a cure-all for static electricity problems. Some insulators do not adsorb moisture from the air; therefore, high humidity will not noticeably decrease their surface resistivity. Examples of such insulators are uncontaminated surfaces of some polymeric materials, such as plastic piping, containers, and films, and the surface of petroleum liquids. These surfaces are capable of accumulating a static electric charge even when the atmosphere has a humidity of 100 percent.

• Movement will also "charge" the capacitor (in this case the human body), just like a balloon does when rubbed on carpeting, hair, etc. It is important to note that as long as the patient remains grounded and the ground has been verified, there should be little to no concern of the risk of fire. If connected to the ground, the accumulated charge will dissipate to the grounded chamber hull.
• Many chamber manufacturers recommend the use of an ohm meter (multimeter that reads ohms) to verify that the chamber hull is grounded to earth. LINK1 This device, as well as a wrist strap continuity tester can be used to verify that the wrist strap worn by the patient and grounding cord has continuity and is connected to the grounded chamber. LINK2

Relevant NFPA 99 references regarding electrostatic safeguards:

14.2.9.4.1.3 - The resistance between the grounded chamber hull and the electrical ground shall not exceed 1 ohm.

14.3.1.6.3.2 - In Class A and Class B chambers with atmospheres containing more than 23.5 percent oxygen by volume, electrical grounding of the patient shall be ensured by the provision of a high-impedance conductive pathway in contact with the patient's skin.

14.3.4.6 Electrostatic Safeguards

14.3.4.6.1 - Conductive accessories shall meet conductivity and antistatic requirements.

14.3.4.6.2 - Patient ground shall be verified in Class B chambers prior to each chamber operation.

14.3.4.6.3 - Patient ground shall be verified in Class A chambers prior 'to chamber operation whenever atmospheres containing more than 23.5 percent oxygen by volume are used.

14.3.4.6.4 - Chamber ground shall be verified to be in accordance with 14.2.9.4.1.3 for Class A and Class B chambers as part of the preventive maintenance program of the facility.

REFERENCES:

1. Burman, F. (2019). Risk Assessment Guide for Installation and Operation of Clinical Hyperbaric Facilities (6th ed.). San Antonio, TX: International ATMO, Inc.
2. International ATMO, Inc., “Static Electricity and Grounding in Hyperbaric Chambers,” Accessed 10/14/2022.
3. National Fire Protection Association. (2021). NFPA 99 2021 Edition: Health Care Facilities Code. Quincy, Massachusetts.
4. National Fire Protection Association. (2019). NFPA 77 2019 Edition: Recommended Practice on Static Electricity. Quincy, Massachusetts.
5. NOVUS Plastic Polish (Product). “NOVUS 1: Clean & Shine,” Accessed 10/14/2022.
6. Undersea and Hyperbaric Medical Society, MEDFAQ Response, “Humidity in the room housing monoplace chambers,” Accessed 10/14/2022.
7. Workman, W. T., & Wood, J. S. (2020). Hyperbaric Facility Safety: A Practical Guide (2nd ed.). Ch. 4.4 Electrical Systems, pg. 192-193. Best Publishing Company.
8. YouTube, “Perry Baromedical Proper Procedure for Patient Grounding,” Accessed 10/14/2022.
9. YouTube, “Sechrist Hyperbaric Chamber Ground Verification,” Accessed 10/14/2022.

Respectfully,

The UHMS HBO₂ Safety Committee

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet. If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility. Information provided on this forum is for general educational purposes only. It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

Is there a protocol for post seizure related to oxygen toxicity? Should a seizure protocol be followed?

Posted: /17/2023

 Q: 
Is there a protocol for post seizure related to oxygen toxicity? Should a seizure protocol be followed?

A:

I am not sure what the reader means by a “seizure protocol.” If this reference is to an in-patient, I would say yes that any nursing protocol for a seizure patients should be followed probably at least for 24 hours.

Usually, if the patient is an outpatient and the patient is neurologically intact and the seizure activity has stopped, they can be sent home with instructions to a family member to observe the patient more carefully for 24 hours. However, It has always been my policy to refer the outpatient to the ER immediately following the seizure. If the patient’s exposure in hyperbaric oxygen was only to 2.0 or 2.4 ATA, we would have to be concerned that a patient experiencing a seizure without a history of a seizure disorder, may have some reason to have a lower threshold for seizure activity and their workup should be accomplished in the same fashion as for any outpatient reporting to the ER with new onset of seizures. This workup would include blood chemistries including electrolytes and blood sugar as well as a CT scan. About 1/3 of adult patients who have a new onset of seizure disorder are found ultimately to have a brain tumor. Obviously, if the patient has a history of malignancy, the likelihood of a brain mass or masses would increase.

The other case that we would need to be considered is a patient with a known seizure disorder who has a seizure in the chamber during hyperbaric oxygen. Most often this sort of patient is found to not have their anti-convulsant drugs at adequate concentrations in the blood stream to suppress seizure activity. They may not be taking their anticonvulsants as prescribed. Blood tests can be done to assess the adequacy of most drugs. This type of patient should see their neurologist for determination of any changes in dosing or drug type. Interestingly, the most common anti-convulsant in adult patients, Dilantin (phenytoin), is not recommended in textbooks of hyperbaric medicine to suppress oxygen toxicity induced seizures. Barbiturates and benzodiazepines, however, are recommended along with some of the newer anticonvulsant dugs drugs.

In a multi-place chamber, with a treatment / dive profile of 2.0 ATA for 90 mins with a standard descent and ascent rate, what is the rationale of offering 15 mins of oxygen breathing at 2ATA (last 15 minutes of bottom time) for the inside tender followed by oxygen decompression (as opposed to air decompression)? This is one of the interventions that is being suggested to minimize DCS risk for the inside tender from one of the facilities. I cannot find any evidence / precedent to support this on a 2ATA fo

Posted: 3/24/2023

Q:
In a multi-place chamber, with a treatment / dive profile of 2.0 ATA for 90 mins with a standard descent and ascent rate, what is the rationale of offering 15 mins of oxygen breathing at 2ATA (last 15 minutes of bottom time) for the inside tender followed by oxygen decompression (as opposed to air decompression)? This is one of the interventions that is being suggested to minimize DCS risk for the inside tender from one of the facilities. I cannot find any evidence / precedent to support this on a 2ATA for 90 mins dive profile. Even for consecutive dives with a surface interval of approximately 30-50 mins, there is no decompression obligation if US navy tables rev 7 (table 9-7 and 9-8) are followed for the treatment profile. I am being quoted a mix from a combination of US navy tables and nobendem tables to support this recommendation. However, I cannot find relevant and applicable evidence to support this. Is there any rationale to use this? One of the concerns I have from a medical standpoint is potential oxygen toxicity for the inside tender from regular exposure to at least one segment of hyperbaric oxygen 1-2 times a day on a daily basis. Kindly advise / opine. Thank you.

A:

Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Hyperbaric Medical Director (HMD) and Hyperbaric Safety Director (HSD) of your facility.

We have had opportunity to clarify some of the questioner’s information above. The facility “standard” treatment table is an 8 to 10-minute compression to a gauge pressure of 33fsw/2 atmospheres absolute (ATA). Then follows 90 minutes of O₂ breathing by patients without air breaks. The Inside Attendant (IA) breathes chamber air for the entirety of the treatment. Finally, an 8 to 10-minute decompression. The total air exposure time for IA is 110 minutes (not the 90 minutes as stated in the above question).

IAs at this facility are allowed a repetitive exposure to the same profile for a second full treatment in a single day. The unit tries to separate the repetitive exposure by one treatment time, but there are times where the IA has finished the first treatment exposure and is recompressed for a second exposure with only a 60-minute surface interval.

The questions for the Safety Committee are as follows: Is there data to support O₂ breathing by the IA? What is the risk of Oxygen toxicity to the IA for 20 minutes of O₂ breathing at 2.0 ATA pressure? Another question arose during followup discussions with the questioner: What is the risk of Decompression Sickness (DCS) when the IA performs repetitive a back-to-back exposure with no O₂ breathing?

Limitations:

Our literature search will primarily include only references to IA DCS. We will try to limit the data to the 2 ATA specifications of this question, but be aware that some of the reviewed literature deals with 2.36 ATA pressures and that many multiplace chambers perform treatments at 2 ATA, 2.36 ATA, 2.5ATA, 2.8 ATA and sometimes greater as part of their daily routines. IA DCS exposure in this setting will over-estimate the risk of IA DCS in a chamber that strictly limits treatments to 2 ATA.

• There is no literature that addresses repetitive IA exposure in the same clinical day, and/or back-to-back repetitive exposures.
• Every exposure to increased pressure puts the IA at risk of DCS if flying or making an excursion to altitude. While the questioner does not state that this is a problem, we encourage the unit to have a policy/procedure for airline/altitude exposure within 12 to 24 hours after being an IA for hyperbaric treatments.

We will list several case reports and medical decision-making disasters for IAs, but these papers are for interest and not germane to the question at hand. Some of the case reports, while well within acceptable pressure limits, expose risks for DCS considering a patent foramen ovale (PFO), physical stress, caffeine use, age, obesity, dehydration, and other contributing factors.

Finally, we note that the hyperbaric chamber treatment profile is considered a “square profile” and may have potentially higher risk for DCS. This is true when attempting to compare a US Navy (or other wet diving table) to the exposure of a hyperbaric chamber treatment.  

Survey of the Literature:

Johnson-Arbor (2012) describes a case report of IA DCS in a 50-y/o man following a 40fsw wound healing treatment table. Of interest is that the unit did not require any oxygen breathing and had a total dive time of 120 minutes. The IA had participated in more than 200 exposures previously without incident. Following this episode, a transthoracic echocardiogram showed a large PFO with easy bubble shunting. The author suggests 10 to 20 minutes of oxygen breathing as a mitigation technique to decrease nitrogen load prior to chamber decompression.

Witucki, et. al. is a case series report of DCS and Oxygen toxicity between 1983 and 2011 at UCSD Hyperbaric Medicine Center. The IAs work in a mix of pressures from 2 – 6 ATA. Occupational guidelines for this facility limit one hyperbaric exposure within a 12-hour period. Any variation from that guideline is addressed on a case-by-case basis. A minimum of 6 hours surface interval is required for staffing a TT6 and 24 hours after a TT6A. Routine treatments in this facility are 2.4 ATA for 110 minutes (but might be longer or shorter based on clinical circumstances).

When studying the risk of DCS by IA, the UCSD group developed three time-based protocols for IA oxygen breathing: Protocol 1 was for a total treatment time (TTT) less than 80 minutes and requires no O2 breathing; Protocol 2 for TTT between 80 and 119 minutes requires 15 minutes of O₂ breathing; and Protocol 3 was between 120 and 139 minutes for 30 minutes of O₂ breathing. The incidence of IA DCS was zero for all three protocols (total exposures overall were 24,616 and most of these fit Protocol 2). There were no reported oxygen toxicity events for IAs.

Kot, et. al. describes a case report of IA DCS on a 2.5 ATA treatment protocol. According to Polish regulations, this profile (6 minutes compression, 70 minutes at pressure, and 6 minutes decompression) requires no oxygen breathing by the IA. The IA decompression schedules are determined by the same regulations for commercial diving operations. The authors conclude that any hyperbaric exposure is an operational risk for DCS.

Pougnet, et. al. performed a multi-center questionnaire review of DCS risk among IAs. The response rate of the survey was n=73. The time covered was approximately 10 years exposure for each respondent. Each respondent had approximately 200 hyperbaric exposures. The study reports 2 cutaneous DCS cases and 3 cases of DCS. By person, there was a 6.8% risk of DCS, but by exposures, the risk was 0.062%.

Perdrizet (2012), in a commentary paper for UHM Journal discusses limitations on reporting and true risk for IAs during hyperbaric exposure. While this paper does not address the question at hand it is well worth reading for a perspective into overall risk.

Clarke (2017) summarizes the existing literature regarding healthcare worker risk for DCS. We highly recommend this paper for your review. Clarke discusses risk of IA DCS and mitigation interventions by multiple institutions. Almost all of these have IA exposures at 2.36 ATA or higher (and/or in a mixed bag of pressures per IA over time). He discusses IA risk mitigation procedures at various institutions in the world.

There is a section (pg. 517) where 2 ATA exposure is discussed. The nitrogen risk (less than 120 minutes total treatment time) presents a smaller inert gas load. However, he does not address repetitive treatments in the same day. He concludes that adding a 10–20-minute period of oxygen breathing would be a conservative intervention.

One of the senior physicians in the UHMS Safety Committee shared personal information that may not have been published formally. During research for traumatic brain injury (TBI) and HBOT, one IA had been exposed to 2 ATA (at sea level) for 60 minutes (total treatment time) for 4 times in one day. This IA developed DCS and was treated. Using this case as a warning, they initiated O₂ breathing by the IA during the treatment profile.

Oxygen toxicity:

Of all the papers reviewed, there were no reports of oxygen toxicity among inside attendants.

Summary:

While there is available data that may be used to answer the question presented, there will be no clear consensus. We recommend conservative protection for the IA in a hyperbaric environment.

Oxygen is used at many facilities as a safety measure for inside attendants in multiplace chambers. This is done most often at the end of the treatment profile and during decompression. This practice has been called “zero time” as the nitrogen clock essentially stops when breathing oxygen at pressure. Since this practice is not scientifically validated, the use of oxygen should be considered an adjunct and not a sole mechanism to stop the bottom time. Some hyperbaric units continue to use the USN air diving tables as written and as if the IA was breathing air for the entire time, regardless of oxygen use or not. We raise this as an example of inadequate science for IA Oxygen breathing during hyperbaric exposure. In the examples given to answer this question, each unit has somewhat different solutions to the problem of IA DCS due to hyperbaric treatment pressures.

We have demonstrated that the use of oxygen breathing by the IA has shown to be an effective tool in lowering the risk of decompression sickness. We recommend that the unit apply the data presented with the needs of the individual clinic. There is no “one size fits all” solution for this question.

It is important to note that the USN tables are written for the Navy diver subjected to in-water exposures and cases of DCS within these tables are to be expected. The tables are not written for the IA in a hyperbaric air environment, noting that the IA may not be as physically fit as a Navy diver. We do not recommend “pushing” tables to the limits. We suggest always staying well below the limits set in the tables for the hyperbaric IA.

Respectfully,

The UHMS HBO₂ Safety Committee

REFERENCES:

1. Bell, J., Thombs, P. A., Davison, W. J., & Weaver, L. K. (2014). Decompression tables for inside chamber attendants working at altitude. Undersea & Hyperbaric Medicine: Journal of the Undersea and Hyperbaric Medical Society, Inc, 41(6), 505-513. LINK
2. Clarke, R. (2017). Health care worker decompression sickness: incidence, risk and mitigation. Undersea & Hyperbaric Medicine: Journal of The Undersea and Hyperbaric Medical Society, Inc, 44(6), 509-519.
3. Johnson-Arbor, K. (2012). Type II decompression sickness in a hyperbaric inside attendant. Undersea & Hyperbaric Medicine, 39(5), 915.
4. Kot, J., Lenkiewicz, E., Lizak, E., Góralczyk, P., & Chreptowicz, U. (2021). Spinal cord decompression sickness in an inside attendant after a standard hyperbaric oxygen treatment session. Diving and Hyperbaric Medicine, 51(1), 103.
5. Naval Sea Systems Command. (2016). US Navy Diving Manual (7th ed.). United States Navy Publication.
6. Pougnet, R., Pougnet, L., Lucas, D., Henckes, A., Loddé, B., & Dewitte, J. D. (2018). Health effects of hyperbaric exposure on chamber attendants: a literature review. International Maritime Health, 69(1), 58-62.
7. Perdrizet, G. A. (2012). Type II DCS in an inside hyperbaric attendant: commentary. Undersea & Hyperbaric Medicine, 39(5), 869.
8. UHMS HBO2 Safety Committee response to MEDFAQ, Accessed 2/28/2023, Originally published 2/2/2017.
9. Witucki, P., Duchnick, J., Neuman, T., & Grover, I. (2013). Incidence of DCS and oxygen toxicity in chamber attendants: a 28-year experience. Undersea & Hyperbaric Medicine: Journal of the Undersea and Hyperbaric Medical Society, Inc, 40(4), 345-350.
10. Workman, W. T., & Wood, J. S. (2020). Hyperbaric Facility Safety: A Practical Guide (2nd ed.). Best Publishing Company.
11. Zwart B. (1998) The “Nobendem” air/nitrox decompression profile calculator: a physiologic model extension based on the U.S. Navy standard air decompression tables. LINK

DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet.  If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility.  Information provided on this forum is for general educational purposes only.  It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.

I work with monoplace chamber and am curious to know what the consensus is on whether or not to use alcohol prep pads for capillary finger stick procedures with in the same room as the chamber prior to placeing patient in for treatment? I understand the risk of alcohol inside the chamber but my medical director and I can not come up with a standard procedural policy as to why or why not we can or could not perform the test with in the chamber room. Can some one provide the resource location or science s

Posted 4/26/2023

Q:
I work with monoplace chamber and am curious to know what the consensus is on whether or not to use alcohol prep pads for capillary finger stick procedures within the same room as the chamber prior to placing patient in for treatment? I understand the risk of alcohol inside the chamber, but my medical director and I cannot come up with a standard procedural policy as to why or why not we can or could not perform the test within the chamber room. Can someone provide the resource location or science stating the possibility of a 2x2 70% alcohol prep pad used on a single digit a few feet from the chamber may or may not have a potential risk of vapor contamination or contribute to a fire hazard? Thank you in advance.

A:

Thank you for your question. The UHMS HBO₂ Safety Committee can provide information to assist you in answering your question, but the ultimate responsibility for these types of questions rests with the Hyperbaric Medical Director (HMD) and Hyperbaric Safety Director (HSD) of your facility.

In the case of 70% isopropyl alcohol pads, this Committee recommends that there is thoughtful control over these items to ensure that they do not end up making their way into the chamber, as alcohol is prohibited in the Class B (monoplace) per NFPA 99 (2021):

14.3.1.6.2.3 Flammable liquids, gases, or vapors shall not be permitted inside any Class B chamber.

We are not aware of any code that would prohibit the use of alcohol prep pads in the room housing the chamber(s). However, this Committee recommends that the facility develops specific processes to this effect, and that pre-treatment safety checks are performed to ensure that the pads are always accounted for prior to commencement of treatments. The medical and safety directors for the facility have the responsibility to develop and enact policies and procedures for hyperbaric operations. It would be wise to consult with the local infection control, laboratory, and risk management teams as you decide the safe and proper practice for your facility.

On flammable vapors near, but not in the chamber:

Outside of the chamber and before the door closes, it may be possible to determine the relative time for alcohol and vapors to evaporate from the skin, thereby reducing the risk of introduction into the chamber. Many Committee members felt that fire risk in this instance is very negligible. Fire triangle: minimal fuel that evaporates over a short time, normobaric air, no heat source.

On alternative solutions:

Out of an abundance of caution with concern that pads may be inadvertently left in the chamber, some class B chamber facilities have removed all alcohol containing products, choosing to use aqueous-based soaps in dispensers, and Benzalkonium Chloride wipes in place of alcohol prep pads. In addition to this, some facilities chose to remove alcohol-containing caps on IV lines, reverting to “scrub the hub” methods. In the case of alcohol hand dispensers near the chambers, there is a risk of damage to the acrylic surfaces of the chamber if they come into direct contact with alcohol-based sanitizer. However, vapor damage to acrylic is very unlikely (See ASME/PVHO-2 mandatory appendix V, partial list of harmful substances and acceptable products).

Regarding source control of prohibited items:

If your facility chooses to use alcohol prep pads for capillary finger stick procedures within the same room as the chamber prior to treatment, we recommend that the alcohol prep pad is policed as part of a pre-treatment safety checklist to ensure that no prohibited items end up in the chamber. It is prudent to establish a process for maintaining repeatability that is acceptable to the safety director and medical director.

Considerations for Multiplace facilities:

Typically, pre-treatment glucose checks are done within the clinic in a nearby staging area. For glucose checks performed mid-treatment, at least two facilities have used the following process:

1. An unsealed cup containing one sealed alcohol prep pad, a pipette, and a lancet is passed through the medical lock of the multiplace chamber.
2. The sample is drawn into the pipette.
3. The cup and all contents are placed back into the medical lock and sent to the surface.
4. The sample is entered into the glucometer at the surface.

This is shown to be an effective way of bypassing in-chamber glucose tests, as some glucometers are not pressure compatible. The Hyperbaric Medical Director and Hyperbaric Safety Director should consult their infection control, laboratory, and risk management teams prior to instituting this as their process.

Respectfully,

The UHMS HBO2 Safety Committee

REFERENCES:

1. Burman, F. (2019). Risk Assessment Guide for Installation and Operation of Clinical Hyperbaric Facilities (6th ed.). San Antonio, TX: International ATMO, Inc. LINK
2. Undersea and Hyperbaric Medical Society, MEDFAQ Response, “Aerosolized Anti-fungal Spray,” Accessed 4/24/2024, LINK
3. Undersea and Hyperbaric Medical Society, MEDFAQ Response, “Protocol Regarding Purell Hand Sanitizer,” Accessed 4/24/2023, LINK
4. Undersea and Hyperbaric Medical Society, MEDFAQ Response, “IV Port Disinfection Caps in the Monoplace or Multiplace Hyperbaric Environment,” Accessed 4/24/2023, LINK
5. Undersea and Hyperbaric Medical Society, MEDFAQ Response, “Use of Alcohol Swabs in the Multiplace Hyperbaric Chamber,” Accessed 4/24/2023, LINK
6. National Fire Protection Agency (NFPA). (2021). “NFPA 99 2021 Edition: Health Care Facilities Code.” Quincy, Massachusetts. LINK
7. Workman, W. T., & Wood, J. S. (2020). Hyperbaric Facility Safety: A Practical Guide (2nd ed.). Best Publishing Company.

 DISCLAIMER

Neither the Undersea and Hyperbaric Medical Society (UHMS) staff nor its members are able to provide medical diagnosis or recommend equipment over the internet. If you have medical concerns about hyperbaric medicine you need to be evaluated by a doctor licensed to practice medicine in your locale, which can provide you professional recommendations for hyperbaric medicine based upon your condition. The responsibility of approving the use of equipment resides with the physician and safety director of the facility. Information provided on this forum is for general educational purposes only. It is not intended to replace the advice of your own health care practitioner and you should not rely upon it as though it were specific medical advice given to you personally.