Bloch, Konrad E., Tsogyal D. Latshang, and Silvia Ulrich. Patients with
obstructive sleep apnea at altitude. High Alt Med Biol 16:110-116, 2015.--Obstructive
sleep apnea (OSA) is highly prevalent in the general population, in particular in men and women of older age. In OSA patients sleeping near sea level, the
apneas/hypopneas associated with intermittent
hypoxemia are predominantly due to upper airway collapse. When OSA patients stay at altitudes above 1600 m, corresponding to that of many tourist destinations, hypobaric
hypoxia promotes frequent
central apneas in addition to obstructive events, resulting in combined intermittent and sustained
hypoxia. This induces strong sympathetic activation with elevated heart rate,
cardiac arrhythmia, and systemic
hypertension. There are concerns that these changes expose susceptible OSA patients, in particular those with advanced age and co-morbidities, to an excessive risk of cardiovascular and other adverse events during a stay at altitude. Based on data from randomized trials, it seems advisable for OSA patients to use
continuous positive airway pressure treatment with computer controlled mask pressure adjustment (autoCPAP) in combination with
acetazolamide during an altitude sojourn. If CPAP
therapy is not feasible,
acetazolamide alone is better than no treatment at all, as it improves oxygenation and
sleep apnea and prevents excessive blood pressure rises of OSA patients at altitude.