Central Sleep Apnea at High Altitude

Figure

High number of central events, comprising apneas and hypopneas, per hour of PAP therapy use (AHI, apnea–hypopnea index, violet bars) during a trip to Peru (altitude profile, black line). Fluctuations in AHI with increasing altitude due to unstable ventilatory control, progressive acclimatization, and varying wakefulness despite consistently good therapy adherence (data source: AHI from the ResMed AirView telemonitoring platform).

During a telemedicine consultation, telemonitoring of a positive airway pressure (PAP) device in a 60-year-old patient with obstructive sleep apnea revealed an unexplained episode of new-onset central apneas and hypopneas. Central respiratory events of this kind are not unusual during treatment initiation but are rare after long-term use. The patient reported traveling to Peru and spending nights at altitudes of up to 4000 m.Accordingly, telemonitoring documented the altitude-dependent occurrence of up to 45 central respiratory events per hour of therapy use. This physiological phenomenon occurs due to a hyperventilatory response to the reduced oxygen partial pressure at altitude. Hyperventilation leads to reduced respiratory drive secondary to decreased carbon dioxide levels in the blood. Even the general population is affected, but particularly those with sleep apnea, who may experience impaired sleep quality and reduced daytime performance. In individuals with cardiac or pulmonary comorbidities, existing nocturnal hypoxemia may worsen. The use of azetazolamide can reduce the occurrence of central respiratory events at high altitude.

Dr. rer. nat. Torsten Eggert, Prof. Dr. med. Christoph Schöbel, Dr. med. Dirk Westhölter, Zentrum für interdisziplinäre Telemedizin und Telecare, Universitätsmedizin Essen, [e-mail]

Conflict of interest statement: CS received honoraria for consultancy from Inspire, Lilly, ResMed, SomnoMed, and ZOLL. He is a board member of the GermanSociety of Sleep Research and Sleep Medicine (Deutsche Gesellschaft für Schlafforschung und Schlafmedizin) and the German Society of Telemedicine (Deutsche Gesellschaft für Telemedizin). The remaining authors declare that no conflict of interest exists.

Translated from the original German by Christine Rye.

Cite this as: Eggert T, Schöbel C, Westhölter D: Central sleep apnea at high altitude. Dtsch Arztebl Int 2026; 123: 195b. DOI: 10.3238/arztebl.m2025.0217