Analysis of mean transcutaneous capnography in consecutive patients undergoing polysomnography

Abstract

Transcutaneous capnography is a noninvasive method useful for analysis of the behavioral tendency of transcutaneous CO 2 pressure (PtcCO 2 ) in patients undergoing polysomnography, to evaluate respiratory sleep disorders. Objective: Determine normative PtcCO 2 values in normal patients undergoing polysomnography. Method: One hundred seventy-nine patients who underwent polysomnography with simultaneous PtcCO 2 measurement were assessed by means of a transcutaneous capnograph (TCM4 series from Radiomiter). Results: The group classified as normal (N=53) presented a apnea/hypopnea index (AHI) ,5 events/per hour of sleep and their age groups varied between 7 and 76 years of age. Conclusion: Global mean values of PtcCO 2 in the normal group had a Gaussian distribution that varied between 33.1 and 50.0 mmHg (SD 4,363). Such findings allowed the establishment of normative PtcCO 2 values for normal individuals.