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Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-44123

Nussbaumer-Ochsner, Y; Schuepfer, N; Ulrich, S; Bloch, K E (2010). Exacerbation of sleep apnoea by frequent central events in patients with the obstructive sleep apnoea syndrome at altitude: a randomised trial. Thorax, 65(5):429-435.



BACKGROUND Many patients with the obstructive sleep apnoea syndrome (OSA) travel to the mountains for recreational and professional activities while temporarily discontinuing continuous positive airway pressure (CPAP) treatment. A study was undertaken to evaluate the hypothesis that altitude would aggravate their hypoxaemia, sleep-related breathing disturbances and impair daytime performance. METHODS Thirty-four patients with OSA of median age 62 years (IQR 57-65), median apnoea/hypopnoea index (AHI) 47.5 events/h (IQR 32.4-72.8), residing at <600 m were enrolled. A crossover trial randomised for the sequence of altitude exposure was carried out: patients spent 1 day in Zurich (490 m) and 4 days in the Swiss Alps at 1860 m and 2590 m (2 days each) during which continuous positive airway pressure was discontinued. Daily evaluations included polysomnography, symptom questionnaires, physical examination and driving simulator tests. RESULTS Polysomnography revealed median oxygen saturations at 490 m and in the first and second nights at 1860 and 2590 m, respectively, of 94%, 90%, 90%, 86% and 87% (p<0.01 between altitudes). Corresponding median AHI were 47.5, 85.1, 74.6, 90.0 and 90.9 events/h (p<0.01 between altitudes) with ratios of central to obstructive events of 0.1, 0.8, 1.0, 1.9 and 1.9 (p<0.01 between altitudes). Tracking performance during simulated driving was significantly impaired at 2590 m compared with 490 m. Systolic blood pressure and cardiac arrhythmias were increased at altitude. CONCLUSIONS Altitude exposure in untreated patients with OSA aggravates hypoxaemia, increases sleep-related breathing disturbances due to frequent central apnoeas/hypopnoeas, impairs driving simulator performance and induces cardiovascular stress. These findings have implications for counselling and treating patients with OSA planning to travel to high altitude. ClinicalTrials.gov identifier NCT00514826.

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > University Hospital Zurich > Clinic and Policlinic for Internal Medicine
04 Faculty of Medicine > Center for Integrative Human Physiology
04 Faculty of Medicine > University Hospital Zurich > Clinic for Pneumology
DDC:570 Life sciences; biology
610 Medicine & health
Deposited On:01 Feb 2011 15:47
Last Modified:27 Nov 2013 23:39
Publisher:BMJ Publishing Group
Publisher DOI:10.1136/thx.2009.125849
PubMed ID:20435865
Citations:Web of Science®. Times Cited: 16
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Scopus®. Citation Count: 19

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