Improvement in Quadriceps Strength and Dyspnea in Daily Tasks After 1 Month of Electrical Stimulation in Severely Deconditioned and Malnourished COPD

Abstract

Low body weight in COPD patients is associated with worsening dyspnea, reduced leg strength, and poor prognosis. Classical rehabilitation strategies are then limited by reduced exercise tolerance. Thus, we proposed to evaluate whether electrostimulation (ES) was a beneficial technique in the rehabilitation programs for severely deconditioned COPD patients after an acute exacerbation. Randomized, controlled study. Pulmonary rehabilitation center. Seventeen patients with severe COPD (mean [ +/- SD] FEV(1), 30 +/- 3% predicted) and low body mass index (BMI) [18 +/- 2.5 kg/m(2)]. Patients were randomly assigned either to usual rehabilitation (UR) alone or to a UR-plus-ES program for 4 weeks. Quadriceps muscle strength, total muscle mass (MM), exercise capacity, and health-related quality of life were measured before and after rehabilitation. The training with ES plus UR induced a significant twofold improvement in the mean number of maximal voluntary contraction (MVC) compared to UR alone (97 +/- 71 vs 36 +/- 34 contractions, respectively; p = 0.03) and resulted in a more significant improvement in dyspnea when performing daily tasks (decrease in the dyspnea domain score of the 28-item Maugeri Foundation Respiratory Failure questionnaire, -1.7 +/- 1.0 vs -0.2 +/- 1.2 points, respectively; p = 0.05). There was also a significant increase in walking distance (63 +/- 40 m; p = 0.01) and BMI (0.6 +/- 0.5 kg/m(2); p = 0.02) after training in the ES + UR group. A significant relationship was found between changes in MVC and changes in MM after training in the ES + UR group (r = 0.94; p = 0.03). The combination of ES and UR was associated with greater improvement in quadriceps strength and dyspnea during the performance of daily tasks than UR alone in severely disabled COPD patients with low BMI. In this population, ES has been revealed as a useful procedure, complementing the usual pulmonary rehabilitation.