Number 1

2022 UHMS Annual Scientific Meeting Abstracts and Author Index 10.22462/01.02.2022.9

Background and Purpose: Following carbon monoxide (CO) poisoning, altered mental status is an important predictor of poor neurological prognosis, including delayed neurological sequelae (DNS). However, it is difficult to interview CO-poisoned patients accurately about exposure intervals and loss of consciousness (LOC). Thus, we investigated whether DNS can be predicted using objective factors such as laboratory results and brain imaging in patients suffering CO poisoning with altered mental status. Methods: This was a prospective observational study involving all CO-poisoned patients who visited the university hospital emergency department (ED) in Bucheon, South Korea, between January 2019 and April 2020. All were registered in the CO registry. We excluded patients who were under 18 years of age, had no change in mental status, were lost to follow-up, had neurological deficits persisting at discharge from the ED, and/or were transferred from another hospital 24 hours after exposure. Results: A total of 21 (25.3%) of 82 patients had DNS with a median onset of 21 (12 to 30) days. Creatinine kinase (CK) (odds ratio 1.0002, 95% confidence interval 2.734-105.231) and brain imaging (odds ratio 3.206, 95% confidence interval 1.008-10.199) were independent prognostic factors of DNS. Conclusions: A high level of serum CK and abnormal brain-imaging results were significant ..

Subcutaneous and mediastinal emphysema are known complications of liposuction and body sculpting procedures. Treatment options are limited, and recovery is often prolonged. We discuss a case of severe subcutaneous and mediastinal emphysema after a skin-tightening procedure involving helium gas. The patient received one treatment of hyperbaric oxygen and was followed until symptom resolution. We review the known literature on hyperbaric oxygen therapy as a treatment for subcutaneous emphysema. 10.22462/01.02.2022.7

Background: Chemotherapy-induced neuropathic pain (CINP) is intractable, and spinal cannabinoid receptors (CBRs) are potential therapeutic targets for CINP. Previous studies demonstrated that hyperbaric oxygen (HBO2) may contribute in alleviating specific peripheral neuropathic pain. However, neither CINP nor CBR have been clarified. We hypothesized that HBO2 is capable of alleviating CINP, and the effect could be explained by the activation of spinal CBRs. Methods: A series of paclitaxel-induced CINP models were established on male Sprague-Dawley rats. Then HBO2 treatment was administered for seven consecutive days at 2.5 atmospheres absolute. Two groups were treated with AM251 (an antagonist of CBR type-1, CBR1) or AM630 (an antagonist of CBR type-2, CBR2) respectively 30 minutes before each HBO2 treatment. The mechanical withdrawal threshold was assessed before, during and at two weeks after HBO2 treatment. Lumbar spinal cords were collected for Western blot analysis of CBR1, CBR2, GFAP and CD11b, and ELISA analysis of proinflammatory cytokines IL-1β and TNF-α. Results: A mechanical allodynia was successfully exhibited and the spinal GFAP, CD11b, IL-1β and TNF-α significantly increased after the modeling, and these effects could be further reversed by HBO2 treatment, which could be blocked by AM630, other than AM251. Conclusions: HBO2 treatment can alleviate paclitaxel-induced neuropathic pain, and ..

Hyperbaric oxygen therapy is an existing and approved treatment to address multiple medical conditions, including decompression sickness, air or gas embolism, carbon monoxide poisoning, and profound blood loss when transfusion cannot be accomplished. However, recent efforts have emerged to promote hyperbaric oxygen therapy for other purposes. The most controversial applications have been utilizing this therapy as a treatment for mild traumatic brain injury and post-traumatic stress disorder. As evidence accumulates and the debate continues about whether published studies have satisfied the threshold of clinical significance, a common issue is raised regarding current clinical practices and health insurance coverage as allowed or recommended by the Department of Defense and other federal agencies. This review describes the current federal policies regarding medical insurance issues for providers and clinical practice guidelines as they pertain to alternative uses of hyperbaric oxygen therapy. First, the current policies are explored for what is reimbursable under federal insurance as approved clinical or research usages. Second, these policies are compared to the clinical practice guidelines to determine what might be clinical best practice versus exploratory research. Third, the evidence from government reports is reviewed as supporting documentation for these positions. As such, the current discussion addresses what can ..

Sepsis is a life-threatening condition for which new therapies are needed. The objective of this literature review was to compile evidence related to the use of hyperbaric oxygen (HBO2) therapy in sepsis. The goal of this analysis was to determine whether human trials are indicated. The study was designed as a narrative review of literature for studies of HBO2 therapy in sepsis. Literature was reviewed to understand potentially beneficial and harmful clinical and physiological effects of HBO2 therapy in animals with sepsis. HBO2 has several physiologic mechanisms which may be beneficial in sepsis, including restoration of mitochondrial function, improved microvascular function and organ perfusion, decreased capillary leak, improved cytokine profile, direct antimicrobial effects, and enhanced antibiotic function. The studies reviewed suggest that HBO2 therapy may be most effective if administered early and in high doses. Animal trials also show that HBO2 may provide protection to the gut mucosa by preventing bacterial translocation in sepsis. HBO2 has a potential to reduce organ failure through novel sepsis mechanisms not used in other therapies. Further human studies should be performed to better elucidate the role of HBO2 in improving sepsis clinical outcomes. 10.22462/01.02.2022.4

A recent rise in snorkeling-related deaths in Hawaii has inspired several bans on full face snorkel masks (FFSMs). However, while there are theories to explain the deaths, little physiological data exists about the way the FFSMs provide gas to an exercising subject. To evaluate the safety of the FFSM concept, this  study was designed to test how use of a full face snorkel mask (FFSM) may be physiologically different than use of a conventional snorkel, and to assess if any of those differences could lead to increased risk for the snorkeler. Ten (10) volunteer human subjects were tested using a variety of commercially available FFSMs, with real-time monitoring of blood oxygen saturation (SpO2), inspired airway pressure, and inspired and expired levels of carbon dioxide and oxygen. Two of the three FFSM design types were shown not to function as advertised, but none of the masks provided physiologically problematic gas supplies to the snorkelers. While this testing yielded no conclusive “smoking gun” to explain the snorkeler deaths, some of the mask models showed patterns of increasing breathing resistance with water intrusion because of a shared design characteristic, and this increased resistance could potentially create elevated levels of respiratory distress to snorkelers ..

Purpose: To identify the most prevalent health conditions among divers during their last year of Navy service. Methods: For this retrospective descriptive study we used data from the Dive Jump Reporting System to identify 4,623 active-duty divers who separated between 2008 and 2018. Medical records, dive histories, and personnel files were merged, linked and analyzed at the individual level. Results: On average, 420 divers separated each year. Among the separating divers, 99% were male, 26% were aged 25 to 29 years old with a mean age of 35 (SD = 9, range 18 to 65). The major medical categories with the highest numbers of divers affected were: musculoskeletal system diseases (prevalence rate (PR) = 515.2 per 1,000 divers/year); nervous system (PR = 411.9); injury and poisonings (PR = 249.8); and mental disorders (PR = 237.3). Of the 50 specific conditions that affected the most divers the top four were joint disorders (PR = 34.5), disorders of refraction and accommodation (PR = 30.1), back disorders (PR = 26.8) and organic sleep disorders (PR = 21.6). Compared to divers with fewer than 29 dives, divers with 49-plus dives were about twice as likely to have diagnoses related to symptoms involving head and neck. Conclusions: ..

High pressure is an environmental characteristic of the deep sea that may exert critical effects on the physiology and mental abilities of divers. In this study we evaluated the performance efficacy and mental ability of four divers during a 300-meter helium-oxygen saturation dive at sea. Spatial memory, 2D/3D mental rotation functioning, grip strength, and hand-eye coordination ability were examined for four divers during the pre-dive, compression, decompression, and post-dive phases. The results showed that both the reaction time and the correct responses for the mental rotation and hand-eye coordination were slightly fluctuated. In addition, there was a significant decline in the grip strength of the left hand. It is concluded that the performance efficacy and mental ability of divers were virtually unaffected during 300-meter helium-oxygen saturation diving at sea. 10.22462/01.02.2022.1