title: Excess ventilation and ventilatory constraints during exercise in patients with chronic obstructive pulmonary disease.
abstract: We assessed the relationship between minute ventilation/carbon dioxide output (VE/VCO2) and ventilatory constraints during an incremental cardiopulmonary exercise testing (CPET) in patients with chronic obstructive pulmonary disease (COPD). Slope and intercept of the VE/VCO2 linear relationship, the ratios of inspiratory capacity/total lung capacity (IC/TLC) and of tidal volume (VT) over vital capacity (VTpeak/VC) and IC (VTpeak/IC) and over forced expiratory volume at 1st second (VTpeak/FEV1) at peak of exercise were measured in 52 COPD patients during a CPET. The difference peak-rest in end-tidal pressure of CO2 (PETCO2) was also measured. VE/VCO2 intercept showed a negative correlation with IC/TLC peak (p<0.01) and a positive one with VTpeak/FEV1 (p<0.01) and with PETCO2 peak-rest (p<0.01). VE/VCO2 slope was negatively related to VTpeak/VC, VTpeak/IC and VTpeak/FEV1 (all correlations p<0.05) and to PETCO2 peak-rest (p<0.01). In COPD, VE/VCO2 slope and intercept provide complementary information on the ventilatory limitation to exercise, as assessed by changes in the end-expiratory lung volume and in tidal volume excursion.
authors.affiliation: Respiratory Disease and Lung Function Unit, Department of Clinical and Experimental Medicine, University of Parma, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Teopompi
authors.affiliation: Respiratory Disease and Lung Function Unit, Department of Clinical and Experimental Medicine, University of Parma, Italy.
authors.forename: Panagiota
authors.initials: P
authors.lastname: Tzani
authors.affiliation: Respiratory Disease and Lung Function Unit, Department of Clinical and Experimental Medicine, University of Parma, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Aiello
authors.affiliation: Respiratory Disease and Lung Function Unit, Department of Clinical and Experimental Medicine, University of Parma, Italy.
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Gioia
authors.affiliation: Respiratory Disease and Lung Function Unit, Department of Clinical and Experimental Medicine, University of Parma, Italy.
authors.forename: Emilio
authors.initials: E
authors.lastname: Marangio
authors.affiliation: Respiratory Disease and Lung Function Unit, Department of Clinical and Experimental Medicine, University of Parma, Italy. Electronic address: chetta@unipr.it.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Chetta
mesh_terms: D000328:Adult; D000368:Aged; D002245:Carbon Dioxide / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011312:Pressure; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000503:physiopathology*; D012123:Pulmonary Ventilation; D012129:Respiratory Function Tests; D013990:Tidal Volume; D014109:Total Lung Capacity; D014797:Vital Capacity
chemical_list: D002245:Carbon Dioxide
keywords: COPD; Exercise; Ventilatory response