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ABSTRACT Bronshteyn V, Hendriksen SM, Lee SJ, Logue C. Surviving cardiac arrest after carbon monoxide poisoning treated with hyperbaric oxygen therapy. Undersea Hyperb Med. 2024 First Quarter; 51(1):37-40. Carbon monoxide (CO) and cyanide poisoning are frequent causes of morbidity and mortality in cases of house and industrial fires. The 14th edition of guidelines from the Undersea and Hyperbaric Medical Society does not recommend hyperbaric oxygen (HBO2) treatment in those patients who have suffered a cardiac arrest and had to receive cardiopulmonary resuscitation [1]. In this paper, we describe the case of a 31-year-old patient who received HBO2 treatment in the setting of cardiac arrest and survived. Keywords: carbon monoxide; cardiac arrest; cyanide; hyperbaric medicine; hyperbaric oxygen; hyperbaric oxygen therapy DOI:10.22462/577

ABSTRACT Sack RA, Pikkel YY, Leitner Shemy O, Ramon Y, Ullmann Y, Zeltzer AA. Transcutaneous oximetry values in chronic ulcer patients during Hyperbaric treatment at 1.4 ATA compared to 2 ATA. Undersea Hyperb Med. 2024 First Quarter; 51(1):1-5. Chronic wounds have a significant impact on a patient’s quality of life. Different pathologies, such as poor blood supply and tissue breakdown, may lead to inadequate oxygenation of the wound. Hyperbaric oxygen (HBO2) is a widely used treatment for an increasing number of medical practices. A new so-called “hyperbaric treatment” trend has emerged. The use of low-pressure, soft-sided, or inflatable chambers represents a growing trend in hyperbaric medicine. Used in professional settings as well as directly marketed to individuals for home use, they are promoted as equivalent to clinical hyperbaric treatments provided in medical centers. However, these chambers are pressurized to 1.3 atmospheres absolute (ATA) on either air or with an oxygen concentrator, both generate oxygen partial pressures well below those used in approved hyperbaric centers for UHMS-approved indications. A total of 130 consecutive patients with chronic ulcers where tested. TcPO2 was measured near the ulcer area while the patient was breathing 100% O2 at 1.4 ATA for five and 10 minutes. The average ..

ABSTRACT Liu A, Hou X, Nie J, Wen Q, Pan Z. Decompression sickness followed by diabetic ketoacidosis and sepsis shock: an unusual case report. Undersea Hyperb Med. 2024 First Quarter; 51(1):41-46. Decompression sickness (DCS) is caused by abrupt changes in extracorporeal pressure with varying severity. Symptoms range from mild musculoskeletal pain to severe organ dysfunction and death, especially among patients with chronic underlying disease. Here, we report an unusual case of a 49-year- old man who experienced DCS after a dive to a depth of 38 meters. The patient’s symptoms progressed, starting with mild physical discomfort that progressed to disturbance of consciousness on the second morning. During hospitalization, we identified that in addition to DCS, he had also developed diabetic ketoacidosis, septic shock, and rhabdomyolysis. After carefully balancing the benefits and risks, we decided to provide supportive treatment to sustain vital signs, including ventilation support, sugar- reducing therapy, fluid replacement, and anti-infection medications. We then administered delayed hyperbaric oxygen (HBO2) when his condition was stable. Ultimately, the patient recovered without any sequelae. This is the first case report of a diver suffering from DCS followed by diabetic ketoacidosis and septic shock. We have learned that when DCS and other critical illnesses are ..

ABSTRACT Keeler JM, Hess HW, Tourula E, Chapman RF, Johnson BD, Schlader ZJ. Relation between resting spleen volume and apnea-induced increases in hemoglobin mass. Undersea Hyperb Med. 2024 First Quarter; 51(1):59-69. Introduction: Indigenous populations renowned for apneic diving have comparatively large spleen volumes. It has been proposed that a larger spleen translates to heightened apnea-induced splenic contraction and elevations in circulating hemoglobin mass (Hbmass), which, in theory, improves O2 carrying and/or CO2/pH buffering capacities. However, the relation between resting spleen volume and apnea- induced increases in Hbmass is unknown. Therefore, we tested the hypothesis that resting spleen volume is positively related to apnea-induced increases in total Hbmass. Methods: Fourteen healthy adults (six women; 29 ± 5 years) completed a two-minute carbon monoxide rebreathe procedure to measure pre-apneas Hbmass and blood volume. Spleen length, width, and thickness were measured pre-and post-five maximal apneas via ultrasound. Spleen volume was calculated via the Pilström equation (test-retest CV:2 ± 2%). Hemoglobin concentration ([Hb]; g/dl) and hematocrit (%) were measured pre- and post-apneas via capillary blood samples. Post-apneas Hbmass was estimated as post-apnea [Hb] x pre-apnea blood volume. Data are presented as mean ± SD. Results: Spleen volume decreased from pre- (247 ± 95 mL) to post- (200 ..

ABSTRACT Öçbe M, Sümen SG, Altun BD, Dumlu A. Barodontalgia during hyperbaric oxygen therapy of an 8-year-old male: A case report. Undersea Hyperb Med. 2024 First Quarter; 51(1):47-51. Barodontalgia, barometric pressure-induced dental pain, may occur during hyperbaric oxygen (HBO2) therapy due to pressure changes. This case report presents an 8-year-old male patient with barodontalgia. The patient declared a severe toothache during HBO2 therapy. The diving medicine specialist referred the patient to the dental clinician immediately. On clinical examination, the pain was thought to be caused by caries lesions of the deciduous teeth in the left maxillary molar region. Tooth extraction was suggested. After extraction, the patient continued hyperbaric oxygen therapy sessions without any pain. The patient was recommended for an intraoral and radiographic examination session one week after the extraction. In conclusion, caries lesions and faulty restorations should be examined before hyperbaric oxygen therapy sessions. Even though barodontalgia is a rare phenomenon, dental examination is essential to avoid these kinds of pain-related complications. All carious lesions and defective restorations must be treated, if necessary. Removal of faulty restorations and management of inflammation as part of the treatment is suggested before exposure to pressure changes. Keywords: barodontalgia; dental pain; diving medicine; hyperbaric oxygen ..

ABSTRACT Gall RA, Rahimi RR. Arterial Gas Embolism in Breath-Hold Diver. Undersea Hyperb Med. 2024 First Quarter; 51(1):93-95. An arterial gas embolism (AGE) is a potentially fatal complication of scuba diving that is related to insufficient exhalation during ascent. During breath-hold diving, an arterial gas embolism is unlikely because the volume of gas in the lungs generally cannot exceed the volume at the beginning of the dive. However, if a diver breathes from a gas source at any time during the dive, they are at risk for an AGE or other pulmonary overinflation syndromes (POIS). In this case report, a breath-hold diver suffered a suspected AGE due to rapidly ascending without exhalation following breathing from an air pocket at approximately 40 feet. Keywords: arterial gas embolism (AGE); breath-hold diving; freediving; pulmonary barotrauma; pulmonary overinflation syndrome (POIS) DOI:10.22464/624

ABSTRACT Jacoby H, Camporesi E, Ross S, Sucandy I, Bosco G, Syblis C, Crespo K, Rosemurgy A. Outcomes after pancreaticoduodenectomy with or without preoperative hyperbaric oxygen therapy. Undersea Hyperb Med. 2024 First Quarter; 51(1):7-15. Background: Hyperbaric oxygen (HBO2) therapy is an alternative method against the deleterious effects of ischemic/reperfusion (I/R) injury and its inflammatory response. This study assessed the effect of preoperative HBO2 on patients undergoing pancreaticoduodenectomy. Study design: Patients were randomized via a computer-generated algorithm. Patients in the HBO2 cohort received two sessions of HBO2 the evening before and the morning of surgery. Measurements of inflammatory mediators and self-assessed pain scales were determined pre-and postoperatively. In addition, perioperative variables and long-term survival were collected and analyzed. Data are presented as median (mean ± SD). Results: 33 patients were included; 17 received preoperative HBO2, and 16 did not. There were no intraoperative or postoperative statistical differences between patients with or without preoperative HBO2. Erythrocyte sedimentation rate (ESR), IL-6, and IL-10 increased slightly before returning to normal, while TGF-alpha decreased before increasing. However, there were no differences with or without HBO2. At postoperative day 30, the pain level measured with VAS score (Visual Analog Score) was lower after HBO2 (1 ± 1.3 vs. 3 ..

ABSTRACT Lee D, Yang H, Ju J. Physical and Physiological Predictors Determining the Maximal Static Apnea Diving Time of Male Freedivers. Undersea Hyperb Med. 2024 First Quarter; 51(1):85-92. This study aimed to investigate what factors determine freedivers' maximal static apnea dive time. We correlated some physical/physiological factors with male freedivers’ maximum apnea diving duration. Thirty-six experienced male freedivers participated in this study. The divers participated in two days of the experiments. On the first day, apnea diving time, blood oxygen saturation (SpO2), heart rate (HR), blood pressure (BP), stress index, and blood parameters were measured before, during, and after the apnea diving in the pool. On the second day, body composition, lung capacity, resting and maximal oxygen consumption (VO2max), and the Wingate anaerobic power were measured in the laboratory. The data were analyzed with Pearson’s Correlation using the SPSS 22 program. The correlation coefficient (R) of determination was set at 0.4, and the level of significance was set at p<0.05. There were positive correlations of diving experience, maximum SpO2, and lung capacity with the maximum apnea time R>0.4, P<0.05). There were negative correlations of BMI, body fat percentage, body fat mass, minimum SpO2, stress index, and total cholesterol with the maximum apnea ..

ABSTRACT Clarke RE, Van Meter K. Medical and surgical management of pneumothorax in diving and hyperbaric chambers. Undersea Hyperb Med. 2024 First Quarter; 51(1):17-28. The presence of a pneumothorax within a pressurized chamber represents unique diagnostic and management challenges. This is particularly the case in the medical and geographic remoteness of many chamber locations. Upon commencing chamber decompression, unvented intrapleural air expands. If its initial volume and/or degree of chamber pressure reduction is significant enough, a tension pneumothorax will result. Numerous reports chronicle failure to diagnose and manage in- chamber pneumothorax with resultant morbidity and one fatal outcome. Such cases have occurred in both medically remote and clinically based settings. This paper reviews pneumothorax and tension pneumothorax risk factors and clinical characteristics. It suggests primary medical management using the principle of oxygen-induced inherent unsaturation in concert with titrated chamber decompression designed to prevent intrapleural air expanding faster than it contracts. Should this conservative approach prove unsuccessful, and surgical venting becomes necessary or otherwise immediately indicated, interventional options are reviewed. Keywords: chest tube; inherent unsaturation; pigtail catheter; recompression chamber; saturation decompression; tension pneumothorax; thoracotomy DOI:10.22462/651

ABSTRACT Clarke RE, Van Meter K. Pneumothorax during manned chamber operations: A summary of reported cases. Undersea Hyperb Med. 2024 First Quarter; 51(1):29-35. In-chamber pneumothorax has complicated medically remote professional diving operations, submarine escape training, management of decompression illness, and hospital-based provision of hyperbaric oxygen therapy. Attempts to avoid thoracotomy by combination of high oxygen partial pressure breathing (the concept of inherent unsaturation) and greatly slowed rates of chamber decompression proved successful on several occasions. When this delicate balance designed to prevent the intrapleural gas volume from expanding faster than it contracts proved futile, chest drains were inserted. The presence of pneumothorax was misdiagnosed or missed altogether with disturbing frequency, resulting in wide-ranging clinical consequences. One patient succumbed before the chamber had been fully decompressed. Another was able to ambulate unaided from the chamber before being diagnosed and managed conventionally. In between these two extremes, patients experienced varying degrees of clinical compromise, from respiratory distress to cardiopulmonary arrest, with successful resuscitation. Pneumothorax associated with manned chamber operations is commonly considered to develop while the patient is under pressure and manifests during ascent. However, published reports suggest that many were pre-existing prior to chamber entry. Risk factors included pulmonary barotrauma-induced cerebral arterial gas ..

ABSTRACT Evgenidis SP, Zacharias K, Papadopoulou V, Theunissen S, Balestra C, Karapantsios T. In-field use of I-VED electrical impedance sensor for assessing post-dive decompression stress in humans. Undersea Hyperb Med. 2024 First Quarter; 51(1):71-83. Purpose: Ultrasound imaging is commonly used in decompression research to assess venous gas emboli (VGE) post-dive, with higher loads associated with increased decompression sickness risk. This work examines, for the first time in humans, the performance of a novel electrical impedance spectroscopy technology (I-VED), on possible detection of post-dive bubbles presence and arterial endothelial dysfunction that may be used as markers of decompression stress. Methods: I-VED signals were recorded in scuba divers who performed standardized pool dives before and at set time points after their dives at 35-minute intervals for about two hours. Two distinct frequency components of the obtained signals, Low-Pass Frequency-LPF: 0-0.5 Hz and Band-Pass Frequency-BPF: 0.5-10 Hz, are extracted and respectively compared to VGE presence and known flow-mediated dilation trends for the same dive profile for endothelial dysfunction. Results: Subjects with VGE counts above the median for all subjects were found to have an elevated average LPF compared to subjects with lower VGE counts, although this was not statistically significant (p=0.06), as well as significantly decreased ..