Analysis of mean transcutaneous capnography in consecutive patients undergoing polysomnography

Análise da capnografia transcutânea média em indivíduos consecutivamente submetidos à polissonografia

Abstract

Transcutaneous capnography is a noninvasive method useful for analysis of the behavioral tendency of transcutaneous CO₂ pressure (PtcCO₂) in patients undergoing polysomnography, to evaluate respiratory sleep disorders.

Objective  Determine normative PtcCO₂ values in normal patients undergoing polysomnography.

Method  One hundred seventy-nine patients who underwent polysomnography with simultaneous PtcCO₂ 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 PtcCO₂ 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 PtcCO₂ values for normal individuals.

polysomonography; transcutaneous capnography; CO₂ pressure