Pneumothorax During Mechanical Ventilation in Patients With Amyotrophic Lateral Sclerosis: Incidence, Risk Factors, and Impact on Survival

ABSTRACT Introduction/Aims Pneumothorax is a complication of mechanical ventilation (MV) in patients with amyotrophic lateral sclerosis (ALS); however, its clinical features and risk factors are not well defined. This study aimed to characterize the incidence, risk factors, and prognostic impact of pneumothorax in patients with ALS undergoing MV. Methods We retrospectively analyzed clinical data from patients with ALS admitted to our center between 2014 and 2024. Patient demographics and baseline characteristics, pneumothorax occurrence, MV details, chest computed tomography (CT) findings, and survival outcomes were reviewed. We analyzed independent risk factors for pneumothorax and evaluated cumulative incidence and survival. Results Among the 131 patients with ALS, 95 underwent MV, 19 of whom developed pneumothorax. Only low body mass index (BMI) (< 18.5 kg/m 2 ; p = 0.015) was identified as an independent risk factor. The cumulative incidence rates of pneumothorax at 1, 3, 5, and 10 years after MV initiation were 4.5%, 13.4%, 24.3%, and 32.0%, respectively. The median post‐pneumothorax survival was 16 months (95% confidence interval CI: 6–67), with no significant difference in overall survival from the time of initiation of MV between patients with and without pneumothorax ( p = 0.88). Discussion This study identified low BMI as a potential risk factor for pneumothorax in ALS patients receiving MV. However, given the limited sample size, these findings should be interpreted with caution. Larger, multicenter studies are warranted to validate this association and to further elucidate long‐term pulmonary effects and preventive strategies.