[Periodic breathing at high altitude relation to acclimatization and acute mountain sickness].

Periodic breathing (PB) during sleep at an altitude of 5100 m was studied with a pulse oximeter. The subjects were six Japanese who stayed at about 5100 m (group A), nine Japanese who climbed above 7000 m (group B) and eight Sherpase (high landers). Among Japanese subjects, PB was observed most often in group A. The sherpas almost never breathed periodically. PB and symptoms of acute mountain sickness correlated positively among Japanese subjects. The cycle time of PB did not differ among the three groups. PB may be related to acclimatization.