The effects of inspiratory muscle training on physical function in critically ill adults: Protocol for a systematic review and meta-analysis

INTRODUCTION: Inspiratory muscle training (IMT) is one possible strategy to ameliorate respiratory muscle weakness due to invasive mechanical ventilation. Recent systematic reviews have focused on respiratory outcomes with minimal attention to physical function. The newest systematic review searched the literature until September 2017 and a recent preliminary search identified 5 new randomized controlled trials focusing on IMT in critical care. As such, a new systematic review is warranted to summarize the current body of evidence and to investigate the effect of IMT on physical function in critical care. MATERIALS AND METHODS: We will search for three main concepts ("critical illness", "inspiratory muscle training", "RCT") across six databases from their inception (MEDLINE, EMBASE, Emcare, AMED, CINAHL, CENTRAL) and ClinicalTrials.gov. Two reviewers will independently screen titles, abstracts, and full texts for eligibility using the Covidence web-based software. Eligible studies must include: (1) adult (≥18 years) patients admitted to the intensive care unit (ICU) who required invasive mechanical ventilation for ≥24 hours, (2) an IMT intervention using a threshold device with the goal of improving inspiratory muscle strength, with or without usual care, and (3) randomized controlled trial design. The primary outcome of interest will be physical function. We will use the Cochrane Risk of Bias Tools (ROB2) and will assess the quality of the evidence using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool. This protocol has been reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA- P) guidelines and is registered with the International Prospective Register of Systematic Reviews (PROSPERO). CONCLUSION: Results will summarize the body of evidence of the effect of IMT on physical function in critically ill patients. We will submit our findings to a peer-reviewed journal and share our results at conferences.