Emergency PaO2 estimates in one minute with a transcutaneous oxygen sensor

Blood was applied directly to the electrode surface of a transcutaneous oxygen sensor (PtcO2) and the oxygen tension value obtained was compared to oxygen tension value from a conventional blood gas machine. Three hundred and seventeen blood samples were analyzed at four PtcO2 electrode temperatures: 37, 40, 42, and 45 degrees C. A linear regression of PO2 vs. PtcO2 blood drop (PbdO2) produced correlation coefficients (r) from 0.99 to 0.93 and standard errors from 3.2 to 4.7 torr at these temperatures. The mean time for stabilization was 51 sec. The PO2 ranged from 4--150 torr. The authors conclude that an accurate PO2 of blood can be obtained within 1 min by placing a drop of blood on the surface of a PtcO2 electrode.