Correlation of arterial and transcutaneous po2s following wet and dry calibration techniques: a comparison study

Transcutaneous oxygen monitoring has gained wide acceptance in many clinical settings in recent years as a technique that provides a reliable, noninvasive method of assessing serial Po2 changes. With the evolution of electrodes and the proliferation of brands, a question has arisen regarding the accuracy of various calibration techniques. In this study we compared the performance of the transcutaneous Po2 monitor (Radiometer Model TCM-1), using two common calibration techniques. During one year of use we applied a wet calibration technique suggested by the manufacturer of our system. With this calibration method, the correlation coefficient for simultaneous arterial and transcutaneous Po2 measurements was 0.91. During a second year we used a much simpler, less costly dry gas technique. The results of simultaneous arterial and transcutaneous Po2 measurements revealed no statistically or clinically significant difference in the performance of the electrode. We conclude that a simple dry gas method of calibrating the transcutaneous Po2 electrode may safely be substituted for the more expensive and cumbersome wet method.