Respiratory strength training in individuals with Amyotrophic Lateral Sclerosis: a systematic review with meta-analysis

Background Respiratory muscle rehabilitation is essential for individuals with Amyotrophic Lateral Sclerosis (ALS).Objective To investigate the effects of respiratory strength training in individuals with ALS.Methods Searches were conducted in MEDLINE, CINAHL, Lilacs, and PEDro, investigating respiratory strength training in ALS patients. The outcomes of interest were respiratory strength, pulmonary function, and functional status of individuals with ALS.Results Respiratory strength training significantly improvement maximum inspiratory pressure of 13.4cmH2O (95%CI 4.3to22.5; I2=0%; p=0.004), maximum expiratory pressure of 35.2cmH2O (95%CI 15.9 to 54.7; I2=0%; p<0.001), and peak expiratory flow of 1.3 L/s (95%CI 0.4 to 2.3;I2=0%; p=0.006), in favor of the experimental group. For forced vital capacity (1.1% of predicted; 95%CI −5.7 to 7.9; I2=0%;p=0.75), peak inspiratory flow (−0.7 L/s; 95%CI −1.5 to 0.1; I2=0%;p=0.07), and functionality (2.4 points; 95%CI −2.9 to 7.8; I2=0%; p=0.38), no significant differences were found.Conclusion Respiratory strength training can significantly contribute to improving inspiratory and expiratory muscle strength, as well as peak expiratory flow in ALS patients. However, the effects on other variables remain uncertain. However, the small number of studies with small samples, and studies with insufficient data for inclusion in the meta-analysis compromises the robustness of the conclusions, with low quality of the evidence.