Jean-Paul Richalet, Fabien Pillard1, David LE Moal2, Daniel Rivière1, Philippe Oriol3, Mathias Poussel4, Bruno Chenuel4, Stéphane Doutreleau, Samuel Vergès, Sophie Demanez5, Michel Vergnion5, Jean-Michel Boulet6, Hervé Douard6, Maryse Dupré7, Olivier Mesland7, Romain Remetter8, Evelyne Lonsdorfer-Wolf8, Alain Frey9, Louis Vilcoq9, Anne Nedelec Jaffuel9, David Debeaumont10, Guy Duperrex11, François Lecoq11, Christophe Hédon12, Maurice Hayot12, Guido Giardini13, François J Lhuissier. 1. Université Paul Sabatier III, Faculté de Médecine Purpan, UMR INSERM U1048 Institut des maladies métaboliques et cardiovasculaires, Hôpital Pierre Paul Riquet, Unité de Médecine du Sport, Toulouse, FRANCE. 2. Université Sorbonne Paris Nord, UMR INSERM 1272 Hypoxie et poumon, Bobigny, FRANCE. 3. Institut Régional de Médecine et d'Ingénierie de Sport, Médecine du sport et Myologie, CHU Saint-Etienne, Saint-Etienne, FRANCE. 4. Centre Hospitalier Régional Universitaire de Nancy, Centre Universitaire de Médecine du Sport et Activité Physique Adaptée, Service des Explorations de la Fonction Respiratoire, Université de Lorraine, EA 3450 Développement, Adaptation et Handicap, Nancy, FRANCE. 5. Centre de physiologie de l'effort-CB Move Herve-Julémont, BELGIUM. 6. Hôpital cardiologique, Service maladies coronaires, tests d'effort et readaptation, Pessac, FRANCE. 7. Institut Régional de Médecine du Sport, CHU Nantes, PHU 10, Hôpital Saint Jacques, Nantes, FRANCE. 8. Centre Hospitalier Universitaire de Strasbourg, Service de Physiologie et EFR, Nouvel Hôpital Civil, Strasbourg, FRANCE. 9. Centre Hospitalier Intercommunal Poissy/Saint-Germain, Service Médecine du Sport, Site Saint Germain, Saint-Germain en Laye, FRANCE. 10. Centre Hospitalo-Universitaire de Rouen, Hôpital Charles Nicolle, CIC-CRB 1404, Unité de physiologie respiratoire et de l'exercice, Rouen, FRANCE. 11. Hôpitaux du Pays du Mont Blanc, Consultation de Médecine et Traumatologie du Sport, Montagne, Sallanches, FRANCE. 12. UMR INSERM U1046-CNRS 9214-PhyMedExp, Université de Montpellier, CHU Arnaud de Villeneuve, Montpellier, FRANCE. 13. Ospedale U. Parini-Azienda USL della Valle d'Aosta, Centro di Medicina e Neurologia di Montagna, Aosta, ITALY.
Abstract
PURPOSE: A decision tree based on a clinicophysiological score (severe high-altitude illness (SHAI) score) has been developed to detect subjects susceptible to SHAI. We aimed to validate this decision tree, to rationalize the prescription of acetazolamide (ACZ), and to specify the rule for a progressive acclimatization. METHODS: Data were obtained from 641 subjects in 15 European medical centers before and during a sojourn at high altitude. Depending on the value of the SHAI score, advice was given and ACZ was eventually prescribed. The outcome was the occurrence of SHAI at high altitude as a function of the SHAI score, ACZ prescription, and use and fulfillment of the acclimatization rule. RESULTS: The occurrence of SHAI was 22.6%, similar to what was observed 18 yr before (23.7%), whereas life-threatening forms of SHAI (high-altitude pulmonary and cerebral edema) were less frequent (2.6%-0.8%, P = 0.007). The negative predictive value of the decision tree based was 81%, suggesting that the procedure is efficient to detect subjects who will not suffer from SHAI, therefore limiting the use of ACZ. The maximal daily altitude gain that limits the occurrence of SHAI was established at 400 m. The occurrence of SHAI was reduced from 27% to 12% when the recommendations for ACZ use and 400-m daily altitude gain were respected (P < 0.001). CONCLUSIONS: This multicenter study confirmed the interest of the SHAI score in predicting the individual risk for SHAI. The conditions for an optimized acclimatization (400-m rule) were also specified, and we proposed a rational decision tree for the prescription of ACZ, adapted to each individual tolerance to hypoxia.
PURPOSE: A decision tree based on a clinicophysiological score (severe high-altitude illness (SHAI) score) has been developed to detect subjects susceptible to SHAI. We aimed to validate this decision tree, to rationalize the prescription of acetazolamide (ACZ), and to specify the rule for a progressive acclimatization. METHODS: Data were obtained from 641 subjects in 15 European medical centers before and during a sojourn at high altitude. Depending on the value of the SHAI score, advice was given and ACZ was eventually prescribed. The outcome was the occurrence of SHAI at high altitude as a function of the SHAI score, ACZ prescription, and use and fulfillment of the acclimatization rule. RESULTS: The occurrence of SHAI was 22.6%, similar to what was observed 18 yr before (23.7%), whereas life-threatening forms of SHAI (high-altitude pulmonary and cerebral edema) were less frequent (2.6%-0.8%, P = 0.007). The negative predictive value of the decision tree based was 81%, suggesting that the procedure is efficient to detect subjects who will not suffer from SHAI, therefore limiting the use of ACZ. The maximal daily altitude gain that limits the occurrence of SHAI was established at 400 m. The occurrence of SHAI was reduced from 27% to 12% when the recommendations for ACZ use and 400-m daily altitude gain were respected (P < 0.001). CONCLUSIONS: This multicenter study confirmed the interest of the SHAI score in predicting the individual risk for SHAI. The conditions for an optimized acclimatization (400-m rule) were also specified, and we proposed a rational decision tree for the prescription of ACZ, adapted to each individual tolerance to hypoxia.