Effect of transcutaneous electrode temperature on accuracy and precision of carbon dioxide and oxygen measurements in the preterm infants

Abstract

BACKGROUND: High electrode temperature during transcutaneous monitoring is associated with skin burns in extremely premature infants. We evaluated the accuracy and precision of CO2 and O2 measurements using lower transcutaneous electrode temperatures below 42°C. METHODS: We enrolled 20 neonates. Two transcutaneous monitors were placed simultaneously on each neonate, with one electrode maintained at 42°C and the other randomized to temperatures of 38, 39, 40, 41, and 42°C. Arterial blood was collected twice at each temperature. RESULTS: At the time of arterial blood sampling, values for transcutaneously measured partial pressure of CO2 (PtcCO2) were not significantly different among test temperatures. There was no evidence of skin burning at any temperature. For PtcCO2, Bland-Altman analyses of all test temperatures versus 42°C showed good precision and low bias. Transcutaneously measured partial pressure of O2 (PtcO2) values trended arterial values but had large negative bias. CONCLUSION: Transcutaneous electrode temperatures as low as 38°C allow an assessment of PtcCO2 as accurate as that with electrodes at 42°C.