Diving medical officers as hospitalists: a case of arterial gas embolism following a routine GI procedure.

Arterial gas embolism is a well-described and frequently seen injury encountered in both civilian and military diving operations. It is becoming increasingly reported and potentially increasingly more common in the hospital environment as a complication of more frequent gastroenterology procedures. We present a case of a 49-year-old, active-duty female who developed significant left-sided neurological deficits manifesting as diffuse left-sided weakness, subjective confusion, and severe headache following esophagogastroduodenoscopy. With increased clinical suspicion for arterial gas embolism, the patient was evaluated by the hyperbaric medicine team at our facility and subsequently treated to near-resolution of symptoms by multiple hyperbaric oxygen treatments. This case highlights the importance of considering this rare complication during or following common invasive procedures. Furthermore, the unique training and experience of physicians with expertise in diving medicine and their ability to recognize these types of injury in the hospital setting highlights the importance of continued training in these fields within Military Medicine in addition to civilian Undersea and Hyperbaric Medicine fellowships.

Chronic decompression illness cognitive dysfunction improved with hyperbaric oxygen: a case report.

Introduction: Altitude chamber exposures are used for training to allow aircrew to experience their hypoxia and pressure effect symptoms. Decompression illness (DCI) can occur subsequent to altitude chamber training or in operational aircraft when the cabin altitude is at least 18,000 feet. Definitive emergent treatment is hyperbaric oxygen (HBO2) to decrease bubble size, dissipate excess nitrogen, hyperoxygenate tissue and reduce inflammation. Case report: A 27-year-old female underwent altitude chamber training to 25,000 feet. She developed tingling in both legs and left arm, headache, dizziness, malaise, then difficulty talking. She underwent two HBO2 treatments. Over the next 12 months, she had paresthesia, decreased memory and cognitive function similar to symptoms seen following traumatic brain injury. She was referred 14 months after the event for evaluation. Using pre-deployment Automated Neuropsychological Assessment Metrics (ANAM) and serial tests over 58 HBO2 treatments, the patient demonstrated near-return to her pre-deployment test scores.. Discussion: The reason for HBO2 treatment was based on previous experience with chronic traumatic brain injury subjects where HBO2 improved outcome. The patient's chronic neurological symptoms mimicked chronic TBI. The patient was unique in that baseline cognitive tests existed that could be used to monitor her changes during the treatment series.

Increased circulating stem cells and better cognitive performance in traumatic brain injury subjects following hyperbaric oxygen therapy.

Traumatic brain injury (TBI) may cause persistent cognitive dysfunction. A pilot clinical study was performed to determine if hyperbaric oxygen (HBO2) treatment improves cognitive performance. It was hypothesized that stem cells, mobilized by HBO2 treatment, are recruited to repair damaged neuronal tissue. This hypothesis was tested by measuring the relative abundance of stem cells in peripheral blood and cognitive performance during this clinical trial. The subject population consisted of 28 subjects with persistent cognitive impairment caused by mild to moderate TBI suffered during military deployment to Iraq or Afghanistan. Fluorescence-activated cell sorting (FACS) analysis was performed for stem cell markers in peripheral blood and correlated with variables resulting from standard tests of cognitive performance and post-traumatic stress disorder: ImPACT, BrainCheckers and PCL-M test results. HBO2 treatment correlated with stem cell mobilization as well as increased cognitive performance. Together these results support the hypothesis that stem cell mobilization may be required for cognitive improvement in this population.

Cognitive function in a traumatic brain injury hyperbaric oxygen randomized trial.

OBJECTIVE: Determine changes in cognition and post-traumatic stress disorder (PTSD) symptoms in subjects with traumatic brain injury (TBI) exposed to 2.4 atmospheres absolute (atm abs) breathing 100% oxygen vs. sham (1.3 atm-abs air). METHODS: Fifty randomized subjects completed a total of 30 exposures. A concussion history was taken, then baseline, post-series, and six-week follow-up immediate post-concussion assessment and cognitive testing, Brain-checkers and PTSD Checklist for Military (PCL-M) tests were administered. RESULTS: No statistically significant differences between groups were noted, but both groups improved. Subgroups analyses, based on concussion history and individual test components, showed improvement in the treatment group vs. the sham. These subgroups included the number of concussive events, time from event to consent, loss of consciousness, visual memory, processing, go--no go, and simple reaction time. CONCLUSION: There was no statistically significant difference between a sham and 2.4 atm abs hyperbaric oxygen (HBO2) in cognitive scores from ImPACT and Brain-checkers or composite scores in the PCL-M; however both groups showed improvement. Subgroups with favorable response to treatment are identified. Future studies evaluating HBO2 should consider concussion histories or focus on validating subgroup response to determine HBO2 as a potential adjunctive treatment for persistent symptoms following TBI.