Proposed Topic (Most preferred): :
Research and Innovations (new projects / technology / innovations / service models)
Authors (including presenting author) :
Lau CW(1), Leung SY(2), Wah SH(1), Yip CW(1), Wong WY(1), Chan KS(1)
Affiliation :
(1) Department of Medicine, Haven of Hope Hospital (2) Department of Physiotherapy, Haven of Hope Hospital
Introduction :
Early commencement of rehabilitation might counteract the loss of muscle strength due to a chronic obstructive pulmonary disease acute exacerbation (COPDAE). Blood flow restriction resistance exercise (BFR-RE) using a low intensity of training load has demonstrated muscle strength gain in varieties of clinical populations. This trial aimed at studying the efficacy and acceptability of BFR-RE in patients with post-COPDAE which was not reported before.
Objectives :
The current study was to evaluate the hypothesis that low-load resistance training with BFR demonstrates more muscle strength gain, better functional improvement and similar acceptability/feasibility than conventional low-load resistance training without BFR in patients with post-COPDAE. The primary outcome of the study was to compare the change of localized muscle strength of knee extension of the dominant leg with or without blood flow restriction (BFR) on the same low-load resistance exercise training in the conventional in-patient pulmonary rehabilitation program. The secondary outcomes of the study were to investigate any functional improvement, any change of systemic muscle strength, any change of health-related quality of life, any difference of unplanned readmission rate for acute exacerbation within 1 month after current discharge, and the acceptability of BFR-RE.
Methodology :
A prospective, assessor blinded, randomized controlled study with 2-week in-patient rehabilitation program with BFR-RE was compared to a matched program with resistance exercise without BFR in patients with post-COPDAE. The primary outcome of the study was to compare the change of localized muscle strength in term of maximal voluntary isometric contraction (MVIC) of knee extension of the dominant leg with or without blood flow restriction (BFR) on the same low-load resistance exercise training in the conventional in-patient pulmonary rehabilitation program. The secondary outcomes of the study were to investigate any functional improvement in term of Short Physical Performance Battery (SPPB), 6-min walk test (6MWT), any change of systemic muscle strength in term of hand grip strength, any change of health-related quality of life in term of self-administered Chinese version of COPD assessment test (CAT) and any difference of unplanned readmission rate for acute exacerbation within 1 month after current discharge with additional BFR to resistance exercise in in-patient pulmonary rehabilitation program. The acceptability of BFR-RE was explored in the study in term of “Pain score” before, immediate and 5-min post exercise measured by visual analog scale (0 to 10). Participants’ acceptance was self-rated by a “5-point Likert categorical scale” after the whole program. Drop-out rate and reasons of drop-out were assessed to determine the feasibility of BFR-RE.
Result & Outcome :
Forty-Five post-COPDAE patients (mean age = 76 ± 10, mean FEV1%=49% ± 24%) were analyzed. After training, BFR-RE group and control group demonstrated a statistically significant median muscle strength gain of 20 (Interquartile range (IQR) 3 to 38) Newton(N) and 12 (IQR -9 to 30) N respectively. BFR-RE group showed a significant change in SPPB scores, but not in 6MWT distance and HGS after training. Between groups did not have statistically significant different in all primary and secondary outcomes, though with similar acceptability. Drop-out rate due to training-related discomfort in BFR-RE group was 3.7%. BFR-RE is feasible and acceptable in patients with post-COPDAE. A 2-week inpatient pulmonary rehabilitation with BFR-RE improved muscle strength of knee extensors, but not a greater extent than the same rehabilitation program with resistance exercise without BFR. Further studies could be considered with a longer training duration and progression of resistance load. [ClinicalTrials.gov Identifier: NCT04448236].
