The Diagnostic Utility of Bronchoalveolar Lavage in Pulmonary Infections: Study from a tertiary care hospital in Oman.

Objectives: Bronchoalveolar lavage (BAL) is an important diagnostic tool. Despite advancements in microbiological strategies, BAL's yield remains inconsistent. Hence, this study aimed to evaluate the yield of BAL in terms of microbial detection and correlate these results with computed tomography (CT) findings and antimicrobial usage duration before bronchoscopy.

Methods: This retrospective cohort study included all adult patients who underwent bronchoscopy with BAL at Sultan Qaboos University Hospital, Muscat, Oman, from January 2021 to December 2022.

Results: A total of 203 patients underwent bronchoscopy. The primary indication for bronchoscopy was lung infiltrates in patients with haematological malignancies (49.3%). The overall BAL yield was 58.1%. All immunocompromised patients with a halo sign on CT scans had negative BAL galactomannan (GM) results (P = 0.559). In immunocompromised patients, there was a higher prevalence of negative BAL cultures with antibiotics usage, regardless of its usage duration, with rates of 72.7% and 71.4% for durations of 1-5 days and 6-10 days, respectively (P = 0.004). Similarly, there was increasing negative BAL GM in immunocompromised patients with longer antifungal usage durations (94.1% for 1-5 days compared to 100% for 6-10 days; P = 0.610). The BAL yield was higher when more than 1 lobe was lavaged bilaterally (25.4%).

Conclusion: This study revealed a BAL diagnostic yield of 58.1%, aligning with existing literature. Performing BAL on both lungs may enhance this yield. No correlation was found between the CT findings and BAL GM results. The study highlights the importance of early BAL intervention before antimicrobial usage.