Peripheral muscle strength training in bed-bound patients with COPD receiving mechanical ventilation: effect of electrical stimulation

Abstract

Study objective: To compare the effects of active limb mobilization (ALM) with or without electrical stimulation (ES) on muscle strength, respiratory rate (RR), heart rate, oxygen saturation, and time needed to transfer from bed to chair in two groups of patients with COPD.

Design: Randomized, controlled study.

Setting: Respiratory high-dependency care unit.

Patients: Twenty-four bed-bound patients with chronic hypercapnic respiratory failure due to COPD who were receiving mechanical ventilation, with marked peripheral muscle hypotonia and atrophy.

Methods: Patients were randomly assigned either to ALM alone or to ALM plus ES (ALM/ES). ES was applied using square-wave alternate, symmetric, and compensated impulses for 30 min bid. The duration of treatment was 28 days for all patients.

Results: Muscle strength improved significantly in the overall group of patients (from 1.75 +/- 0.73 to 3.44 +/- 0.65, p < 0.05). Comparing the change (end minus beginning) of the analyzed variables, ALM/ES significantly improved muscle strength (2.16 +/- 1.02 vs 1.25 +/- 0.75, p = 0.02) and RR (- 1.91 +/- 1.72 vs 0.41 +/- 1.88, p = 0.004), and decreased the number of days needed to transfer from bed to chair (10.75 +/- 2.41 days vs 14.33 +/- 2.53 days, p = 0.001).

Conclusion: In bed-bound patients with COPD receiving mechanical ventilation, with marked peripheral muscle hypotonia and atrophy, application of ES in addition to classical ALM significantly improved muscle strength and decreased the number of days needed to transfer from bed to chair.