Abstract
BACKGROUND: Airway clearance is a vital aspect of respiratory care in patients with severe acute respiratory failure receiving veno-venous extracorporeal membrane oxygenation (VV-ECMO). These patients often receive high levels of sedation alongside ultra-lung protective invasive mechanical ventilation, which, while reducing ventilator-induced lung injury, significantly impairs physiological mechanisms essential for secretion clearance, such as expiratory flow bias, mucociliary transport, and effective cough. OBJECTIVES: This commentary explores the multifaceted challenges to airway clearance in the VV-ECMO population, evaluating current physiotherapeutic interventions, and identifying critical areas for future research. DISCUSSION: Ultra-lung protective ventilation settings reduce airflow and expiratory shear forces necessary for secretion mobilisation. Concurrent sedation and neuromuscular blockade suppress cough reflexes and promote secretion stasis, while reduced airflow impairs the two-phase gas-liquid flow critical for airway hygiene. Additionally, increased secretion viscosity and altered lung mechanics further limit clearance. Current physiotherapy strategies such as suctioning, hyperinflation, cough augmentation, and manual techniques are often adapted from non-ECMO settings and lack validation in this population. Diagnostic challenges, such as reduced auscultation efficacy, highlight the growing importance of tools like lung ultrasound. Pharmacological adjuncts, including mucolytics and saline lavage, are used despite limited supporting evidence. CONCLUSION: Airway clearance in patients receiving VV-ECMO is hampered by a convergence of physiological, mechanical, and clinical factors. Existing literature remains scarce and largely extrapolated from conventional invasive mechanical ventilation populations. There is an urgent need for targeted research to define evidence-based interventions tailored to the unique pathophysiology of this complex group.