Excess ventilation and ventilatory constraints during exercise in patients with chronic obstructive pulmonary disease

Respir Physiol Neurobiol. 2014 Jun 15;197:9-14. doi: 10.1016/j.resp.2014.03.002. Epub 2014 Mar 19.

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.

Keywords: COPD; Exercise; Ventilatory response.

MeSH terms

  • Adult
  • Aged
  • Carbon Dioxide / metabolism
  • Exercise / physiology*
  • Exercise Test
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pressure
  • Pulmonary Disease, Chronic Obstructive / drug therapy
  • Pulmonary Disease, Chronic Obstructive / physiopathology*
  • Pulmonary Ventilation*
  • Respiratory Function Tests
  • Tidal Volume
  • Total Lung Capacity
  • Vital Capacity

Substances

  • Carbon Dioxide