Usefulness of the Transcutaneous Po2 Monitor During Exercise Testing in Adults

The usefulness of the transcutaneous Po2 monitor for monitoring during stress testing was evaluated. Seventy-five simultaneous recordings of arterial and transcutaneous Po2 were made on 11 patients with chronic obstructive pulmonary disease while they were undergoing treadmill exercise testing. All arterial blood samples were drawn from an indwelling brachial arterial line and analyzed in duplicate. The range of arterial Po2 measured was 50 to 145 mm Hg. The correlation coefficient (relationship between arterial and transcutaneous Po2) was .96 and the slope of the best fit line was 1.047 (Y = 1.047 x -7.2). The transcutaneous Po2 was an average of 5.99 +/- 4.76 mm Hg below the arterial Po2 in the entire group. The mean difference in transcutaneous and arterial Po2 was greater at low Po2 level, than at high levels. We found the electrode easy to maintain and calibrate, with a low frequency of malfunction. This instrument provides a safe, simple, and reliable noninvasive method for recording serial changes in Po2 during exercise testing.