Hypertonic Saline Inhalation for Nontuberculous Mycobacterial Lung Disease

Nontuberculous mycobacterial lung disease (NTM-LD) is a chronic pulmonary infection that frequently progresses despite conservative management. Because prolonged multidrug antibiotic therapy is associated with substantial treatment burden, potential toxicity, and variable effectiveness, additional non-antibiotic treatment strategies are needed, particularly for patients who defer, cannot tolerate, or are not yet indicated for antibiotic treatment. Hypertonic saline inhalation facilitates airway clearance and sputum removal and has been increasingly used as an adjunctive treatment in specialized NTM centers. However, prospective randomized data remain limited, particularly in Asian populations. This multicenter randomized controlled trial investigates whether early initiation of inhaled 3% hypertonic saline improves respiratory symptoms and microbiological outcomes compared with delayed initiation. To ensure treatment safety, all participants undergo a supervised inhalation tolerance assessment before randomization. During this assessment, inhaled salbutamol (Ventolin) premedication is administered, followed by inhalation of 3% hypertonic saline. Participants demonstrating clinically significant intolerance, severe bronchospasm, or other safety concerns are excluded from study treatment. Following successful completion of the tolerance assessment, participants are randomized to one of two groups. The early-initiation group receives inhaled 3% hypertonic saline for 6 months. The delayed-initiation group receives inhaled normal saline during Months 0-3, followed by inhaled 3% hypertonic saline during Months 4-6. The primary randomized comparison is performed at Month 3 between participants receiving hypertonic saline and those receiving normal saline. Additional analyses evaluate within-participant changes in the delayed-initiation arm before and after switching from normal saline to hypertonic saline. Throughout the study, participants continue routine clinical care. Initiation of anti-NTM antibiotic treatment remains at the discretion of the treating physician.