The Use of Airway Clearance Devices in the Management of Chronic Obstructive Pulmonary Disease. A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Rationale: Sputum retention in chronic obstructive pulmonary disease (COPD) is a troubling symptom and can lead to reduced quality of life and increased exacerbations. Airway clearance devices are commonly used in COPD; however, their efficacy is unclear and is inconsistent among cohorts.Objectives: This study aims to systematically review the evidence to determine the impact of airway clearance devices in patients with COPD.Methods: Databases for systematic reviews and published evidence were searched. Studies were included if they were randomized and compared an airway clearance device to usual care or control. Studies were required to report at least one of the following: exacerbations, sputum volume, hospitalizations, and health-related quality of life. Data were extracted and assessed for risk of bias, and outcomes were synthesized using RevMan.Results: Eighteen studies with available data were eligible for this review, totaling 855 participants. Airway clearance devices demonstrated significant improvements in sputum volume (-1.07 ml; -0.37 to -1.77). There were significant improvements in the rate of exacerbation frequency at 6 months (rate ratio, 0.50; 95% confidence interval, 0.30-0.83; P < 0.01). No significant improvement was noted for the Saint George's Respiratory Questionnaire (0.30; -1.56 to -3.41; P = 0.10) in stable patients. There was an improvement of -5.73 (-7.30 to -4.15) for the COPD Assessment Test and -1.72 (-2.85 to -0.59) for the Breathlessness Cough and Sputum Score (P < 0.01).Conclusions: Airway clearance devices can improve exacerbation frequency, sputum clearance, and symptoms in stable COPD. The evidence included in this review was predominantly low- to moderate-grade evidence.