Characteristics of cardiopulmonary exercise test in tracheobronchial tuberculosis patients with central airway stenosis

Abstract

BackgroundA typical symptom of central airway stenosis is progressive dyspnea. The exercise capacity and relationship between pulmonary function testing (PFT) and central airway stenosis have not been reported. ObjectivesTo investigate, for the first time, the impact of central airway stenosis due to tracheobronchial tuberculosis (TBTB) on exercise capacity in adults. MethodsFifty-one patients diagnosed with TBTB and 51 healthy, non-smoking adults (controls) were studied. All participants underwent a maximal cardiopulmonary exercise test (CPET) after completing PFT. ResultsAll participants completed the PFT and CPET. Significant differences existed between the two groups with respect to PFT parameters. At rest, no significant differences were detected between the two groups with respect to oxygen uptake (VO2), vital volume (VT), minute ventilation (VE), end-tidal carbon dioxide (PetCO2), and oxygen pulse (SPO2). Compared to controls, TBTB patients had lower peak work rate [WR, 100 (83,119) vs. 112 (95,146)], VO2 at maximal exercise (1309.51±323.83 vs. 1522.17±451.15), anaerobic threshold (905.8 ± 219.84 vs. 1024.72±296.27), maximal O2 pulse (8.02±1.61 vs. 9.26±2.36), and breath reserve [BR, 25 (15,42) vs. 49.5(39.4,61.3)]. The change in PetCO2 values at rest and maximal exercise was lower than in controls (P<0.05). However, no difference in VE/carbon dioxide production (VCO2)@AT were demonstrated between the two groups. The correlations between the degree of stenosis, PFT parameters, and VO2 peak were significant. RV/TLC%pred was a good predictor of exercise limitation in these patients. ConclusionThe maximal exercise capacity and PFT parameters of TBTB patients with central airway stenosis were impaired. Impaired exercise capacity correlated with the degree of central airway stenosis.