Middle-ear barotrauma after hyperbaric oxygen therapy: a five-year retrospective analysis on 2,610 patients.

Introduction: Hyperbaric oxygen (HBO2) therapy is the use of oxygen or gas mixtures at a pressure above atmospheric pressure for therapeutic purposes. This treatment is used in numerous pathological processes. Its main side effect is middle ear barotrauma (MEB), which represents a great concern for iatrogenic HBO2 therapy. The aim of this work is to describe this adverse event in order to highlight clinical elements that can contribute to its prevention and management. Methods: We conducted a five-year retrospective study from January 2013 to December 2017, where 2,610 patients were selected, in the Hyperbaric Medicine Centre, Sainte- Marguerite Hospital of Marseille, France. Results: 262 patients experienced MEB after HBO2, representing a prevalence of 10.04% and incidence of 0.587%. Their average age was 55 ± 19 years. Women were more affected than men. We have not highlighted a seasonality to this condition. Risk factors were: age older than 55 years, female gender, ear, nose and throat history (cancer, radiotherapy, infections or allergies, malformations or benign tumors), general history (smoking, obstructive breathing disorders, thyroid disorders and obesity), HBO2-approved indications of sudden deafness and delayed wound healing, and altered tympanic mobility on initial examination. Although the benign stages of Haines-Harris classification were the most encountered in our study, MEB was responsible for premature discontinuation of HBO2. Conclusion: MEB is a common condition responsible for many premature discontinuations of HBO2. Its origin is multifactorial, associating non-modifiable and modifiable factors. Better management of this affection will further contribute to making HBO2 a low-risk treatment.

Medical kit for single-handed offshore yacht races.

BACKGROUND: The medical kit is the basis of medical support in maritime environment; it is defined by international or national regulations and guidelines. For offshore races, rules and recommendations are proposed by national or international sailing federations. Sailing and racing offshore alone presents specificities that sometimes make it difficult to apply the usual recommendations. The epidemiology of single-handed offshore race is dominated by traumatic risks. Medical events are relatively rare because competitors are high-level athletes, generally young and subject to complete medical assessments. The scarcity of available scientific data makes it necessary to choose appropriate methods for developing recommendations. The purpose of this work is to propose a medical kit adapted and applicable to these situations. MATERIALS AND METHODS: The method used was that of "Professional recommendations by formal consensus of experts" derived from the Rand/UCLA method. After a critical analysis of the literature, a panel of 19 experts having expertise in medicine in maritime environment was gathered from various medical specialties (cardiologist, internist, intensivist and emergency physician, ear-nose-throat physician and general practitioner) and from varied medical activities. They had not declared any direct conflict of interest. RESULTS: A medical kit proposal has been developed. The choice of drugs was based on the analysis of the epidemiology of medical events observed during the last offshore races. The experts' choice was to reduce the quantity of medication and medical devices in order to limit the risk of confusion of medicines and dosages. Drugs with significant side effects or requiring third party monitoring have been removed. Medical devices designed to do an intervention impossible to perform on oneself have also been eliminated. CONCLUSIONS: Solo sailing remains a marginal maritime activity with specific risks. The development of single-handed races requires an adaptation of medical support through the development of a specific medical kit and adapted training. The formalised consensus of experts seems to be an appropriate method for developing recommendations in the field of maritime medicine.

Preparation and medical follow-up for a single-handed transatlantic rowing race.

BACKGROUND: A single-handed transatlantic rowing race was organised between Senegal and French Guyana (2600 nautical miles). During the race, rowers adjust their lifestyle to maintain an optimal level of performance. Nutrition, circadian rhythm disturbance, psychological state, pain and other medical problems impact on physical abilities and increase the occurrence of accidents. We surveyed the prevalence of medical complications during this race and the preparation that we could suggest for this kind of activity. MATERIALS AND METHODS: This is a descriptive, retrospective case series study. Follow-up consisted of sending out a questionnaire and performing individual interviews. RESULTS: A total of 23 participants including 1 woman and 22 men; mean age of 46.5 years (range: 35-59) entered the race. The race lasted for 39 to 52 days with participants rowing between 10 and 12 h/day. Nine participants dropped out. Energy intake was 4500 to 6000 kcal/day and fluid intake was 4 to 5.5 L/day. Mean weight loss was 13.3 kg. The resting period was 6 ± 1 h/24 h divided into 1.5 to 2 h periods essentially during darkness. A total of 92% of the racers required medical care for dermatological problems; other conditions requiring medical care were: tendinitis in 10 cases, diarrhoea in 4, moderate to severe seasickness in 4, hallucinations in 3, panic attacks in 2, burns in 2, and disembarkation syndrome ("land sickness") lasting from 45 min to 6 h in 13. CONCLUSIONS: Physiological and psychological impact of this type of event is still unclear. The most common medical problems are dermatological, rheumatological complications and minor trauma. Medical and psychological preparation should be offered to candidates for these competitions.

Ischaemia-modified albumin during experimental apnoea.

Ischaemia-modified albumin (IMA) is a marker of the release of reactive oxygen species (ROS) during hypoxaemia. In elite divers, breath-hold induces ROS production. Our aim was to evaluate the kinetics of IMA serum levels during apnea. Twenty breath-hold divers were instructed to perform a submaximal static breath-hold. Twenty non-diver subjects served as controls. Blood samples were collected at rest, every minute, at the end of breath-hold, and 10 min after recovery. The IMA level increased after 1 min of breath-hold (p < 0.003) and remained high until recovery. Divers were separated into 2 groups: subjects who held their breath for less than 4 min (G-4) and those who held it for more than 4 min (G+4). After 3 min of apnoea, the increase of IMA was higher in the G-4 group than in the G+4 group (p < 0.008). However, at the end of apnoea, the IMA level did not differ between groups. If IMA level was globally correlated with the apnoea duration, it is interesting to note that the higher IMA level was not found in the best divers. Similarly, if arterial blood oxygen saturation (SpO2) was globally inversely correlated with apnoea duration, the lowest SpO2 at the end of breath-hold was not found in the divers that performed the best apnoea. We concluded that these divers save their oxygen. The IMA level provides a useful measure of resistance to hypoxaemia.