Transcutaneous measurement of carbon dioxide tension during extended monitoring: Evaluation of accuracy and stability, and an algorithm for correcting calibration drift

Abstract

BACKGROUND: When polysomnography is indicated in a patient with a presumed sleep disorder, continuous monitoring of arterial carbon dioxide tension (PaCO2) is desirable, especially if nocturnal hypoventilation is suspected. Transcutaneous CO2 monitors (PtcCO2) provide a noninvasive correlate of PaCO 2, but their accuracy and stability over extended monitoring have been considered inadequate for the diagnosis of hypoventilation. We examined the stability and accuracy of PtcCO measurements and the performance of a previously described linear interpolation technique designed to correct for calibration drift. METHODS: We compared the PtcCO values from 2 TINA TCM-3 monitors to PaCO values from ar..