Nasal negative pressure oscillatory therapy versus oscillatory positive expiratory pressure for airway clearance in patients with acute exacerbations of bronchiectasis (NNPO-BE): a multicentre, randomised, crossover non-inferiority trial protocol.

Background: Airway clearance techniques (ACTs) are a cornerstone of bronchiectasis management, particularly during acute exacerbations characterized by mucus retention and impaired mucociliary clearance. However, conventional ACTs are frequently limited by patient tolerance, reliance on skilled personnel and variable adherence in real-world settings. Nasal negative pressure oscillatory airway clearance represents a novel, non-invasive strategy designed to enhance expiratory flow bias and promote mobilization of airway secretions. Objectives: To assess whether nasal negative pressure oscillatory (NNPO) airway clearance is non-inferior to standard airway clearance therapy, with oscillatory positive expiratory pressure (OPEP) used as the conventional comparator, in hospitalized patients with acute exacerbations of bronchiectasis. Methods: This is a prospective, multicenter, randomized crossover trial conducted across four tertiary hospitals in China. Eligible participants will receive NNPO and OPEP therapy in random order over four consecutive days. The primary outcome is sputum wet weight collected during and within 30 min after each treatment session. Secondary outcomes include lung function, peripheral oxygen saturation, patient-reported efficacy and comfort, and adverse events. Conclusion: This trial will evaluate the short-term efficacy and safety of nasal negative pressure oscillatory airway clearance compared with conventional airway clearance therapy in hospitalized patients with acute exacerbations of bronchiectasis, providing evidence to inform clinical decision-making in acute management. Systematic review registration: ChiCTR2500105694 PID: 266607, https://www.chictr.org.cn/bin/project/edit?pid=266607.