The validity of the transcutaneous oxygen tension method in adults

The transcutaneous oxygen tension (tcPo2) in five healthy subjects and in seven patients was monitored continuously by the technique of Huch, Huch, and Lübbers. The inspired oxygen concentration was varied between 15 and 100%. Once stable tcPo2 recordings were obtained, blood samples were drawn via an indwelling arterial catheter for oxygen tension (Pao2) determination. A comparison between the Pao2 and the tcPo2 values is illustrated graphically. There was a small difference between these values in the healthy subjects, which was attributed to variations in the skin from subject to subject. In the patients, a circulatory factor may have added to differences in the absolute levels. The coefficient of correlation between Pao2 and tcPo2 was in all cases higher than 0.98. In healthy persons, Pao2 may be predicted from tcPo2. In patients, any change in Pao2, due to deterioration or improvement, is manifested in the tcPo2 curve. If one or two arterial blood measurements are performed, low as well as high Pao2 values may be predicted from tcPo2 in patients without gross circulatory impairment.