The Impact of COVID-19 on the Response to Hypoxia

Louis, Alexandre, Charlotte Pröpper, Yann Savina, Corentin Tanne, Guy Duperrex, Paul Robach, Pascal Zellner, Stéphane Doutreleau, Jean-Michel Boulet, Alain Frey, Fabien Pillard, Cristina Pistea, Mathias Poussel, Thomas Thuet, Jean-Paul Richalet, and François Lecoq-Jammes. The impact of COVID-19 on the response to hypoxia. High Alt Med Biol. 24:321-328, 2023. Background: Severe high-altitude illness (SHAI) and coronavirus disease 2019 (COVID-19), while differing in most aspects of pathophysiology, both involve respiratory capacity. We examined the long-term impact of COVID-19 on response to hypoxia in individuals free of symptoms but having tested positive during the pandemic. The need for recommendations for such individuals planning a stay at high altitude are discussed. Methods: This multicenter study recruited participants from the multiSHAI cohort, all of whom had previously undergone a hypoxic exercise test. These participants were classified into two groups depending on whether they had since suffered mild-to-moderate COVID-19 (COVID+) or not (Control) and then asked to retake the test. Primary outcomes were: desaturation induced by hypoxia at exercise (ΔSpE), hypoxic cardiac response at exercise, hypoxic ventilatory response at exercise, and SHAI risk score. Results: A total of 68 participants retook the test, 36 classified in the COVID+ group. Analyses of primary outcomes showed no significant differences between groups. However, the COVID+ group showed significantly increased ventilation (VE) parameters during both hypoxic (p = 0.003) and normoxic exercise (p = 0.007). However, only the VE/oxygen consumption relationship during hypoxic exercise was significantly different. Conclusion: This study demonstrates no negative impact of COVID-19 on response to hypoxia as evaluated by the Richalet test. Clinical Trial Registration: NTC number: NCT05167357.

Medical mountain rescue in the Mont-Blanc massif

Because of its peculiar geographic location beneath Mont-Blanc, the Chamonix Hospital plays an important role in the management of mountaineering- and skiing-related traumatic injuries. The authors, thanks to the study of 5200 mountain rescue medical reports, set out to explain the different aspects of this activity: epidemiology, specific equipment, care in the field, reception and primary survey, dispatching, common therapeutic attitudes, progress, and results. In the dangerous environment of the high mountains, emphasis is put on the physicians' experience, allowing an early evacuation in the best conditions to the hospital. Diagnosis at the scene of the accident is very basic, and the initial treatment is based on immobilization, analgesia, and sedating. In the case of resuscitation, only the vital maneuvers are performed; these actions are carried on during the short flight and improved in the crash rooms. Finally, different specific pathologies are mentioned, including cold- or heat-related injuries, exhaustion, lightning strikes, and mountain sickness.