RT Journal Article
SR Electronic
T1 Transcutaneous PCO2-based dead space ventilation is highly accurate to discriminate COPD patients from healthy controls at submaximal exercise
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 2560
DO 10.1183/13993003.congress-2020.2560
VO 56
IS suppl 64
A1 Thibault Leprat
A1 Fabrice Ivanes
A1 Marchand-Adam Sylvain
A1 Laurent Plantier
YR 2020
UL http://erj.ersjournals.com/content/56/suppl_64/2560.abstract
AB Background: Increased physiological dead space ventilation (Vd/Vt) at exercise reflects impairment of pulmonary gas exchange and is a sensitive marker of cardio-respiratory disease. At present, Vd/Vt is typically not measured during routine cardiopulmonary exercise testing (CPET) because its calculation requires PaCO2, and thus arterial puncture. Instead, dead space ventilation is indirectly evaluated as a determinant of the ventilation (VE)/VCO2 slope, which also depends on the PaCO2 setpoint. We hypothesized that Vd/Vt calculations based on transcutaneous PCO2 (PtcCO2) measurement had better diagnostic characteristics than the VE/VCO2 slope for the discrimination of healthy subjects from patients with COPD, a common disease with impaired pulmonary gas exchange.Methods: Nineteen healthy Controls and 24 COPD patients underwent CPET with monitoring of PtcCO2. Areas under receiver operating characteristics curves (AUC) were calculated to assess diagnostic accuracy of CPET measurements for the discrimination of COPD and Controls.Results: The AUC for PtcCO2-based Vd/V at VT1 (0.977) was significantly higher than for the VE/VCO2 slope (0.660), SpO2 at peak exercise (0.913), decrease in inspiratory capacity (0.719), and ventilatory reserve (0.708). At a threshold of 0.24, the sensitivity and specificity of PtcCO2-based Vd/Vt were 100% and 84%, respectively.Conclusions: PtcCO2-based Vd/Vt was the most accurate measurement to discriminate healthy controls from subjects with chronic lung disease associated with altered pulmonary gas exchange, ie COPD. Non-invasive monitoring of PtcCO2 may be highly useful for routine CPET.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 2560.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).