Ask a new question
You don't have permission, please login or register

Treatment / Protocol

We are updating our HBO policies and I would appreciate your opinion on how to decompress the 2 following situations...
Published: 14 June 2015

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)?
Published: 12 July 2015

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 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. 

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, 13th edition, Weaver, Best Publishing.
  2. CGA G 4.3: 2015 Commodity Specification for Oxygen, 6th 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.
Published: 26 July 2015

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

pdfUHM_41-6_Altitude_deco_tables_for_IAs.pdf

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

pdfAbsolute 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.
Published: 04 August 2015

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?
Published: 14 January 2016

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
  1. Schwartz, H.J.C., Curley, M.D. (1986). Transdermal scopolamine in the hyperbaric environment [Abstract]. Retrieved from: http://archive.rubicon-foundation.org/3528
  2. 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.
  1. 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.
  1. 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.
  1. 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
  1. 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: 17 May 2016

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: 20 April 2016

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, 13th 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?
Published: 21 December 2016

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.

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

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

pdfDecompression 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: 02 February 2017

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:

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?
Published: 04 June 2018

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

Responder

Primary actions

Subsequent actions

Chamber Operator






  • Notify Attending practitioner:
  • Determine leak source and correct if possible

 

  • If leak is fixed, continue treatment
  • If leak is major decompress the chamber as directed by the practitioner
  • Put the chamber out of service until repaired. 

Attending Practitioner



  • Supervise patient care, evaluations
  • Determine if transfer to another chamber / facility is required
  • Chart as required



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?
Published: 22 May 2018

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 7th 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 4th 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?
Published: 08 February 2018

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.
Published: 03 April 2017

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.
Published: 12 June 2018

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
Published: 30 October 2016

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.

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.?
Published: 14 September 2020

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