Role of cardiopulmonary exercise testing and the criteria used to determine disability in patients with severe chronic obstructive pulmonary disease.

Abstract

The aim of this study was to evaluate the precision and variability with which resting pulmonary function tests (resting PFTs) can be used to predict the capacity in exercise, and the usefulness of the different measurements of pulmonary function in the evaluation of impairment/disability in patients with chronic obstructive pulmonary disease (COPD). We studied 78 patients with stabilized COPD (FEV1 45.1 +/- 17.1%). Of these, 39 suffered severe impairment according to the resting PFTs. Both the group with severe impairment (maximal oxygen consumption [VO2,max]: 16.22 +/- 5 ml/kg/min; maximal minute ventilation [VEmax]: 31.87 +/- 7.1 L/min; maximal heart rate [HRmax]: 133.8 +/- 10.9 beats/min) and the group with nonsevere impairment according to the resting PFTs (VO2max: 22.55 +/- 7.9 ml/kg/min; VEmax: 42.11 +/- 10.9 L/min; HRmax: 138 +/- 13.7 beats/min) showed ventilatory limitation during exercise. FEV1 was the most prevalent criterion for the determination of severe impairment (FEV1 < 40%), and was the variable best correlated to VO2max (r = 0.52 with VO2max as absolute value and r = 0.54 with VO2max expressed as a percentage of the reference value), but the resting PFTs were not predictive of exercise performance including patients with severe COPD. Evaluation of working capacity (based on VO2max) revealed a significant number of inaccurate predictions among the results of the resting PFTs. Sensitivity and specificity analysis were used to compare the different criteria used to evaluate the severity of disability. They reveal that the classification will be different according to the criteria used.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical exercise testing with reference to lung diseases: indications, standardization and interpretation strategies. ERS Task Force on Standardization of Clinical Exercise Testing. European Respiratory Society

“…This is especially true in patients in whom exercise is limited by lung function [3][4][5][6][7][8][9]. This is not only because exertional dyspnoea is not well predicted from pul monary function, but also because many patients with lung disease stop exercising owing to fatigue, chest pain and leg discomfort rather than dyspnoea [3], For these reasons and because measures of health-related quality of life correlate better with exercise tolerance than with either spirometry or oxygenation [9], CPET is a useful tool in the integrated evaluation of common problems such as unexplained dyspnoea on exertion and limita tion of exercise tolerance [39,40].…”

“…CPET is an area of growing interest in pulmonary medicine for three major reasons: 1) its large potential clinical applicability (see section on Indications); 2) the essentially noninvasive nature of the testing; and 3) pro vision of information that cannot be obtained through conventional lung function testing performed at rest [3][4][5][6][7][8][9]. During the past few years, two factors have con tributed to the current level of interest in CPET in pul monary medicine.…”

Increased ventilation with NiIPPV does not necessarily improve exercise capacity in COPD

“…Subjects with chronic obstructive pulmonary disease (COPD) have reduced maximal ventilation at peak exercise [1] and stop exercising despite significant cardiovascular reserve [2]. The application of noninvasive intermittent positivepressure ventilation (NiIPPV) during exercise may increase ventilation, and reduce breathlessness [3], inspiratory effort [3,4] and loading of the inspiratory muscles [5].…”

The haemodynamic response to exercise in chronic obstructive pulmonary disease: assessment by impedance cardiography

“…The haemodynamic response to exercise in chronic obstructive pulmonary disease: assessment by impedance cardiography In most patients with chronic obstructive pulmonary disease (COPD) maximal exercise capacity is diminished, but pulmonary function tests provide a poor prediction of peak exercise oxygen consumption (V 'O 2 ) [1][2][3]. An aberrant haemodynamic response may contribute to the decreased exercise tolerance [4,5].…”