Airway clearance techniques for adults receiving extracorporeal membrane oxygenation for severe acute respiratory failure: a scoping review protocol.

INTRODUCTION: Patients receiving extracorporeal membrane oxygenation (ECMO) for severe acute respiratory failure (SARF) often experience significant challenges with airway clearance due to disease severity, ultra-protective ventilation strategies and suppression of mucociliary and cough mechanisms. Extremely low tidal volumes and minimal flow rates further hinder secretion mobilisation. Despite increasing global use of ECMO, there is currently no synthesis of evidence describing airway clearance practices, their physiological rationale or outcomes in this population.This scoping review aims to explore the extent and nature of evidence on airway clearance interventions in invasively ventilated adult patients receiving ECMO for SARF. Specific objectives include mapping the types of interventions described and specific parameters, their intended physiological effects, reported outcomes and safety considerations. METHODS AND ANALYSIS: This scoping review will be conducted in accordance with the Joanna Briggs Institute methodology and reported using Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines. A comprehensive search will be undertaken across Embase, Ovid Emcare, Ovid Medline, CINAHL and grey literature sources including TRIP and Google Scholar. Eligible studies will include original data on airway clearance interventions in adult patients (≥16 years) receiving ECMO for SARF. Studies focused on paediatric populations, extracorporeal carbon dioxide removal, or solely cardiac ECMO will be excluded.Two independent reviewers will screen titles, abstracts and full texts, extract data using a piloted tool and summarise findings using descriptive statistics and narrative synthesis. Basic qualitative content analysis will support mapping of interventions including parameters, their physiological and clinical rationale, and reported outcomes including adverse effects. ETHICS AND DISSEMINATION: As this study involves a review of existing literature and does not include collection of primary data, ethical approval is not required. Findings will be disseminated through publication in a peer-reviewed journal and presentation at relevant academic and professional meetings. The results are expected to highlight variations in practice and provide a foundation for future research aimed at optimising respiratory care and improving outcomes for patients receiving ECMO for SARF. REGISTRATION: osf.io/ptfr7.