Effect of Positive Expiratory Pressure Therapy on Lung Volumes and Health Outcomes in Adults with Chest Trauma: A Systematic Review and Meta-Analysis

Abstract

Objective: The purposes of this study were to evaluate the effect of positive expiratory pressure (PEP) therapy on lung volumes and health outcomes in adults with chest trauma and to investigate any adverse effects and optimal dosages leading to the greatest positive impact on lung volumes and recovery. Methods: Data sources were MEDLINE/PubMed, Embase, Cochrane Library, Physiotherapy Evidence Database, CINAHL, Open Access Thesis/Dissertations, EBSCO Open Dissertations, and OpenSIGLE/Open Grey. Randomized controlled trials investigating PEP therapy compared with usual care or other physical therapist interventions were included. Participants were >18 years old and who were admitted to the hospital with any form of chest trauma, including lung or cardiac surgery, blunt chest trauma, and rib fractures. Methodological quality was assessed using the Physiotherapy Evidence Database Scale, and the level of evidence was downgraded using the Grading of Recommendations Assessment, Development and Evaluation approach. Results: Eleven studies involving 661 participants met inclusion eligibility. There was very low-level evidence that PEP improved forced vital capacity (standardized mean difference =-0.50; 95% CI =-0.79 to-0.21), forced expiratory volume in 1 second (standardized mean difference =-0.38; 95% CI =-0.62 to-0.13), and reduced the incidence of pneumonia (relative risk = 0.16; 95% CI = 0.03 to 0.85). Respiratory muscle strength also significantly improved in all 3 studies reporting this outcome. There was very low-level evidence that PEP did not improve other lung function measures, arterial blood gases, atelectasis, or hospital length of stay. Both PEP devices and dosages varied among the studies, and no adverse events were reported. Conclusion: PEP therapy is a safe intervention with very low-level evidence showing improvements in forced vital capacity, forced expiratory volume in 1 second, respiratory muscle strength, and incidence of pneumonia. It does not improve arterial blood gases, atelectasis, or hospital length of stay. Because the evidence is very low level, more rigorous physiological and dose-response studies are required to understand the true impact of PEP on the lungs after chest trauma. Impact: There is currently no strong evidence for physical therapists to routinely use PEP devices following chest trauma. However, there is no evidence of adverse events; therefore, in specific clinical situations, PEP therapy may be considered.