Cerebral oxygenation in lowlanders with COPD spending a night at 2590m

Objective There are concerns that altitude travel may induce cerebral hypoxia, in particular in patients with preexisting lung disease and during sleep. Therefore, we investigated cerebral tissue oxygenation (CTO) by near-infrared spectroscopy in lowlanders with COPD spending one night at 2590 m. Methods 37 COPD patients living below 800m (mean±SD age 62.4±12.3y, FEV 1 61±16 %pred.) underwent sleep studies including pulse oximetry (SpO2) and prefrontal CTO recordings at 490m and in the first night after arrival at 2590m. Results During the night at 2590m, SpO2 and CTO were decreased and unstable due to apneas/hypopneas compared to 490m. These changes were less pronounced in CTO than in SpO2 (table). Conclusions Lowlanders with COPD travelling to 2590m experience persistent arterial hypoxemia and cerebral tissue deoxygenation due to reduced barometric pressure and high altitude periodic breathing. The decreases in CTO are less pronounced than those of SpO2 possibly due to cerebrovascular autoregulation. Grant: Swiss National Science Foundation, Lung League Zurich