Six Percent Oxygen Enrichment of Room Air at Simulated 5000 m Altitude Improves Neuropsychological Function

Cognitive and motor function are known to deteriorate with the hypoxia accompanying high altitude, posing a substantial challenge to the efficient operation of high altitude industrial and scientific projects. To evaluate the effectiveness of enriching room air oxygen by 6% at 5000 m altitude in ameliorating such deficits, 24 unacclimatized subjects (16 males, 8 females; mean age 37.8, range 20 to 47) underwent neuropsychological testing in a specially designed facility at 3800 m that can simulate an ambient 5000 m atmosphere and 6% enrichment at 5000 m. Each subject was tested in both conditions in a randomized, double-blinded fashion. The 2-h test battery of 16 tasks assessed various aspects of motor and cognitive performance. Compared with simulated breathing air at 5000 m, oxygen enrichment resulted in higher arterial oxygen saturations (93.0 vs. 81.6%), quicker reaction times, improved hand-eye coordination, and more positive sense of well-being (on 6 of 16 scales), each significant at the p < 0.05 level. Other aspects of neuropsychological function were not significantly improved by 6% additional oxygen.