Transcutaneous PO2 monitoring during a Himalayan ascent.

Transcutaneous PO2 (PtcO2) measurements were taken daily on seven subjects during two nine day ascents of the Himalayas to an altitude of 4,579 meters. Five of the subjects lived in areas under 450 meters (Group I), while two subjects lived at an altitude of 3,100 meters (Group II). The PtcO2 values decreased with increasing altitude. The Group II subjects had PtcO2 values greater than the Group I subjects and the difference became greater with increasing altitude. The linear regression lines of PtcO2/pbO2 to Group I during ascent and decent were lower than the regression line for Group II (PbO2 is the barometric oxygen partial pressure). The regression line for Group I data during the second half of the trek approached the data for Group II. We conclude that acclimatization to high altitude is possibly associated with increasing peripheral tissue oxygenation as assessed by PtcO2 values.