Central Sleep Apnea at High Altitude: From Pathophysiology to Treatment.
At elevations above roughly 2500 m, susceptible individuals manifest central sleep apnea due to high-altitude periodic breathing (high-altitude central sleep apnea [HA-CSA]) characterized by a typical periodic breathing pattern. Mechanistically, HA-CSA develops when sleep-related decreases in respiratory drive, triggered by hypocapnia, resulting from hypoxia-induced hyperventilation, interact with increased loop gain during non-rapid eye movement sleep. Clinically, severity is mitigated by descent or supplemental oxygen. Pharmacologic strategies such as acetazolamide are effective, and sleep quality may improve with judicious hypnotic use independent of CSA severity. This article integrates the description of HA-CSA mechanisms, clinical expression, ethnic and chronic-exposure perspectives, and management strategies.