High Prevalence of Non-Responders Based on Quadriceps Force after Pulmonary Rehabilitation in COPD

Abstract

Pulmonary rehabilitation (PR) in patients with COPD improves quality of life, dyspnea, and exercise tolerance. However, 30 to 50% of patients are “non-responders” (NRs) according to considered variables. Surprisingly, peripheral muscle force is never taken into account to attest the efficacy of PR, despite its major importance. Thus, we aimed to estimate the prevalence of force in NRs, their characteristics, and predictors of non-response. In total, 62 COPD patients were included in this retrospective study (May 2019 to December 2020). They underwent inpatient PR, and their quadriceps isometric maximal force (QMVC) was assessed. The PR program followed international guidelines. Patients with a QMVC increase <7.5 N·m were classified as an NR. COPD patients showed a mean improvement in QMVC after PR (10.08 ± 12.97 N·m; p < 0.001). However, 50% of patients were NRs. NRs had lower pre-PR values for body mass, height, body mass index, PaO2, and QMVC. Non-response can be predicted by low QMVC, high PaCO2, and gender (when male). This model has a sensitivity of 74% and specificity of 81%. The study highlights the considerable number of NRs and potential risk factors for non-response. To systematize the effects, it may be interesting to implement blood gas correction and/or optimize the programs to enhance peripheral and central effects.

Safety and Efficacy of Pulmonary Rehabilitation for Long COVID Patients Experiencing Long-Lasting Symptoms

“…However, at the individual level, upon initiation of the program, the majority of the symptomatic patients had significantly increased muscle strength, as 53% exhibited an increase greater than the MCID. This prevalence of patient responses regarding muscle strength (i.e., 53%) is consistent with the study by Desachy et al, who reported a 50% response rate to QMVC at the end of a PR program in patients with chronic obstructive pulmonary disease [83]. The heterogeneity of responses to muscle strength is an important issue of current PR programs, as seen here for long COVID patients, and it highlights the importance of analyzing individual responses to conclude regarding PR (in)effectiveness and to consider care tailored to each patient.…”

“…This issue has been described, and a specific questionnaire, such as the DePaul Symptom Questionnaire-Post-Exertional Malaise, should be used to assess the prevalence of this symptom [82]. Concerning the relatively high prevalence of respiratory symptoms [23,82,83], this may be linked to an orientation bias of patients by prescribers. Indeed, the program was carried out in a center recognized nationally for its expertise in the management of chronic respiratory diseases, and thus, it is likely that long COVID patients with a high prevalence of respiratory disorders were preferentially referred to this center.…”