Comparing the Accuracy of Mini-BAL to Bronchoscopic BAL in the Diagnosis of Pneumonia Among Ventilated Patients: A Systematic Literature Review

Background: Despite its widespread use, there are no direct studies comparing mini-bronchoalveolar lavage (mini-BAL) to bronchoscopic bronchoalveolar lavage (BAL) for diagnosing pneumonia in ventilated patients. The aim of this study was to perform a systematic review of studies comparing ventilated patients undergoing both bronchoscopic BAL and mini-BAL, to determine the mini-BAL's diagnostic accuracy. Methods: We conducted a systematic review searching the databases PubMed (MEDLINE), EMBASE, Cochrane Library, Scopus, and clinicaltrials.gov from inception until January 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Search terms included variations on “pneumonia,” “critical illness,” and “mini-bronchoalveolar lavage.” Article screening and data extraction were performed independently by 2 reviewers. Results: Our search yielded 4296 abstracts. This was narrowed to 6 studies in which each patient underwent both mini-BAL and bronchoscopic BAL in succession. Included patients had a mean APACHE II score of 20.02 ± 3.81 and 15.95 ± 11.46 ventilator days. The sensitivity of the mini-BAL for diagnosis of pneumonia was 0.90 (95% confidence interval [CI]: 0.778-1.000) and the specificity was 0.827 (95% CI: 0.716-0.938). Limitations included inconsistency in volume of saline instilled and heterogeneity in included patients Conclusion: This study is the first to compile data from multiple publications directly comparing the mini-BAL to bronchoscopic BAL for diagnosing pneumonia in ventilated patients. Our data demonstrate a high degree of both sensitivity and specificity of mini-BAL for the diagnosis of pneumonia in ventilated patients and indicate that mini-BAL could be considered as an acceptable alternative diagnostic study.