Effort tolerance and effectiveness of pulmonary rehabilitation in COPD patients with varying degrees of dyspnea during ADL

Abstract

Background: Scarce literature has shown relationships between dyspnea during Activity Daily Life (ADL) and pulmonary rehabilitation (PR) outcomes.

Objective: To evaluate how different degrees of dyspnea during ADL affect: a) exercise tolerance and b) response to PR in patients with chronic obstructive pulmonary disease (COPD).

Methods: This is a retrospective cohort study conducted in an Italian network of PR hospitals. Exercise tolerance by Six Minute Walking Distance (6MWD) and dyspnea during ADL by Barthel Dyspnea index (BDi) were evaluated in patients with COPD performing an interdisciplinary in-hospital rehabilitative program.

Results: Data from 1057 patients were analyzed (62.44% men; age: 71.51 ± 9.86 years; forced expiratory volume in the first second %:48.31± 24.76; BDi score: 37.67 ± 20.24; 57.6% with Chronic Respiratory Failure). Participants were stratified into 5 quintiles (Q) from low to extreme dyspnea based on baseline BDi and assessed on the basis of baseline and change of 6MWD. At baseline patients with higher dyspnea presented greater exercise intolerance (range: 405 ± 119 meters for 1stQ to 226 ± 109 meters for 5thQ, p <0.001 between groups). All BDi Qs improved 6MWD after PR (average value 58 ± 91.75 meters) without differences between Qs (p =0.4830). Likewise, the percentage of patients who improved more than MDCI was similar among Qs (mean 66.13%, p=0.059). The percentage of improvement (change/ baseline) ranged from 11.92± 22.19 (1st Q) to 38.2 ± 76.7% (5th Q), P = 0.0007.

Conclusions: the presence of higher dyspnea during ADL in COPD is directly related to exercise intolerance. Patients with different level of dyspnea benefits equally from PR.