Safety and harms of bronchoalveolar lavage for acute respiratory failure: A systematic review and meta-analysis

BackgroundThis review aimed to investigate whether bronchoalveolar lavage (BAL) is safe in patients with severe acute respiratory failure (ARF).MethodsWe searched the MEDLINE, CENTRAL, and other databases up to June 2, 2021 for studies that examined BAL for severe ARF. We included all cohort studies and randomized or non-randomized trials, while we excluded case-control studies, case reports, and case series. We evaluated the quality of the evidence using the Grading of Recommendations, Assessment, Development, and Evaluation approach.ResultsWe included 17 studies (1085 patients) in the meta-analysis. The integrated frequency of death was 0.000% (95% confidence interval [CI]: 0.000–0.045%, I² = 0.0%). The pooled risk of severe complications of respiratory system, cardiovascular system, and major bleeding was 1.32% (95% CI: 0.000–4.41%, I² = 84.8%), 0.040% (95% CI: 0.000–0.71%, I² = 9.3%), and 0.000% (95% CI: 0.000–0.27%, I² = 0.0%), respectively. In the subgroup analysis with mechanical ventilation during BAL, there were few severe complications of the respiratory system (3/717 patients in 13 studies) and almost no heterogeneity (I² = 0.0%).ConclusionsOur study suggests that severe complications of BAL for severe ARF are probably rare, particularly in patients receiving mechanical ventilation. After considering the risks and benefits, it would be worthwhile to consider performing BAL in patients with severe ARF of unknown etiology to pursue its cause.Trial registrationThe protocol was registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000040600).