Transcutaneous oxygen monitoring beyond the neonatal period

Transcutaneous O2 (PtcO2) tensions were compared with PaO2 measurements in 57 infants and children (age range 2 wk to 15.5 yr) using electrode temperatures of 43 degrees and 44 degrees C. At both temperatures, the relationships between PtcO2 and PaO2 were linear over the whole range of data (PaO2 39.75 to 120 torr) although mean PtcO2/PaO2 fell from 44 degrees to 43 degrees C. Skin stripping by repeated applications of adhesive tape immediately before electrode placement did not improve these relationships. In an additional 20 children with a mean age of 2.4 yr (range 0.08 to 15.85) who were being investigated for sleep-disordered breathing, the mean PaO2/PtcO2 ratio of 1.22 at 44 degrees C was used as a correction factor during air calibration for PtcO2. This resulted in a mean PtcO2/PaO2 of 0.99 (range 0.83 to 1.15) provided blood flow is not impaired. Extending the monitoring period from 4 to 8 h between site changes did not result in any burns or persisting erythema. In hemodynamically stable infants and children, and at electrode temperatures of 44 degrees C and 43 degrees C, PtcO2 is linearly related to PaO2 over a wide range of PaO2 values. At an electrode temperature of 44 degrees C, PtcO2 can be arterialized effectively by allowing for transepidermal O2 loss during air calibration; at this electrode temperature, intervals between site changes can be extended safely up to 8 h.