Randomized Crossover Study of Lung Expansion Therapy Using Negative Pressure and Positive Pressure in Bronchiectasis

Background: For patients with bronchiectasis, the mechanical mobilization of secretion constitutes a key therapeutic approach. However, the effectiveness of lung expansion therapy to mobilize secretion in bronchiectasis patients has not been investigated extensively. This study compares patients' exercise tolerance and physical assessment outcomes after secretion clearance using intermittent positive pressure breathing (IPPB) or negative pressure ventilation (NPV) as adjuncts to postural drainage. Methods: This prospective, randomized crossover study examined the data for 18 stable outpatients with bronchiectasis. The outcomes were compared for four treatment sessions of either IPPB or NPV, used as adjuncts to postural drainage. The short-term outcomes involved pulmonary functions and a six-minute walk test (6MWT). We also assessed pulmonary functions and physical clinical signs as immediate treatment effects. Results: Patients' forced vital capacity (FVC), forced expiratory volume in the first second (FEV 1), and cough efficacy did not change significantly after individual postural drainage sessions using either IPPB or NPV. However, a reduction in the use of accessory muscles was noted after NPV; patients with low baseline FVC might benefit particularly from this reduction (r = 0.699, p <0.05). No significant differences between two techniques were found for the patient's walking distance. However, the pulse rate after 6MWT was significantly (p <0.05) lower in the NPV group. Conclusion: NPV may provide as an effective adjunct to postural drainage as IPPB in weekly lung expansion therapy for outpatients with bronchiectasis. The benefits of NPV might include a reduction in the use of accessory muscles during lung expansion.