Monitoring of the Cerebral Tissue Oxygenation and Perfusion in the Adapting Climber During Sleep in High Altitude

Under sea level conditions humans breath between 10 and 12 times per minute. The breathing cycle in high altitude is accelerated. If the conscious breathing control vanishes during sleep a periodic breathing with alternating episodes of hyperventilation and apnea is the result. This circumstance causes repetitive arousals that do not allow a normal sleep pattern. The associated adverse effects are fatigue, slow or failed acclimatization, weakening of the immune system, lack of motivation and the disability to make rational decisions. Sleep deprivation is a common reason for the abortion of a trip, accidents and severe forms of Acute Mountain Sickness (AMS).