Transcutaneous PCO2 for Exercise Gas Exchange Efficiency in Chronic Obstructive Pulmonary Disease.

Transcutaneous PCO2 for Exercise Gas Exchange Efficiency in Chronic Obstructive Pulmonary Disease. COPD. 2021 Jan 17;:1-14 Authors: Cao M, Stringer WW, Corey S, Orogian A, Cao R, Calmelat R, Lin F, Casaburi R, Rossiter HB, Porszasz J Abstract Gas exchange inefficiency and dynamic hyperinflation contributes to exercise limitation in chronic obstructive pulmonary disease (COPD). It is also characterized by an elevated fraction of physiological dead space (VD/VT). Noninvasive methods for accurate VD/VT assessment during exercise in patients are lacking. The current study sought to compare transcutaneous PCO2 (TcPCO2) with the gold standard-arterial PCO2 (PaCO2)-and other available methods (end tidal CO2 and the Jones equation) for estimating VD/VT during incremental exercise in COPD. Ten COPD patients completed a symptom limited incremental cycle exercise. TcPCO2 was measured by a heated electrode on the ear-lobe. Radial artery blood was collected at rest, during unloaded cycling (UL) and every minute during exercise and recovery. Ventilation and gas exchange were measured breath-by-breath. Bland-Altman analysis examined agreement of PCO2 and VD/VT calculated using PaCO2, TcPCO2, end-tidal PCO2 (PETCO2) and estimated PaCO2 by the Jones equation (PaCO2-Jones). Lin's Concordance Correlation Coefficient (CCC) was assessed. 114 measurements were obtained from the 10 COPD subjects. The bias between TcPCO2 and PaCO2 was 0.86 mmHg with upper...
Source: COPD: Journal of Chronic Obstructive Pulmonary Disease - Category: Respiratory Medicine Tags: COPD Source Type: research