Risk Factors for Acute Exacerbation Following Bronchoalveolar Lavage in Patients with Suspected Idiopathic Pulmonary Fibrosis: A Retrospective Cohort Study

Introduction: Bronchoalveolar lavage (BAL) is useful for diagnosing diffuse lung disease and excluding other conditions. However, acute exacerbations (AEs) are recognized as important complications of BAL in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to identify risk factors for BAL-induced AEs in patients with IPF. Material and methods: We retrospectively analyzed the data of 155 patients with suspected IPF who had undergone BAL between January 2013 and December 2018. BAL-related AE was defined as the development of AE within 30 days after the procedure. We compared clinical features and parameters between patients with AE (AE group) and without AE (non-AE group). We also reviewed the relevant reported literature. Results: Among the 155 patients, 5 (3.2%) developed AE within 30 days after BAL. The average duration from BAL to AE onset was 7.8 days (2–16 days). Results from the univariate analysis revealed PaO2 < 75 mm Hg (p = 0.036), neutrophil content in BAL ≥ 7% (p = 0.0061), %DLCO < 50% (p = 0.019), Gender-Age-Physiology (GAP) stage III (p = 0.034), and BAL recovery rates < 30% (p < 0.001) as significant risk factors for post-BAL AE. All five patients who developed AE recovered and were discharged. Conclusions: Disease severity, high neutrophil levels in BAL, and poor BAL recovery rates may be risk factors for BAL-induced AEs.