Diagnostic Utility of Bronchoalveolar Lavage in Immunocompromised Patients with Lung Infiltrates

Introduction: Lung infections are associated with a high mortality rate in immunocompromised patients. Achieving an accurate and rapid diagnosis is vital to help guide management, and thus improve survival.

Objective: To establish the diagnostic yield, clinical value, and safety of bronchoscopy with bronchoalveolar lavage (BAL) in immunocompromised adult patients with pulmonary infiltrates.

Methods: This retrospective study included all immunocompromised adult patients who underwent bronchoscopy with BAL for investigation of radiologically confirmed pulmonary infiltrates at a tertiary care hospital between January 01, 2014, and June 30, 2021. Clinically significant findings of BAL were defined as a positive microbiological result of a potential pathogen determined using routine culture, acid-fast bacilli smear, mycobacterial culture, tuberculosis PCR, fungal culture, Aspergillus antigen, and multiplex PCR panel and/or positive cytology.

Results: A total of 103 unique patients were included (mean ± SD age: 44.5 ± 14.1 years), of which the majority were male (60.2%). The BAL diagnostic yield was 52.4% (95% CI: 42.6-62.2%). In the multiple logistic regression model, positive BAL was predicted by symptom of sputum (aOR 4.01, 95% CI: 1.27-12.70, P = 0.018). Almost half of the procedures (43.7%, 95% CI: 33.9-53.4%) resulted in a change in the management plan, with positive BAL findings more than twice as likely to result in a change (OR 2.39, 95% CI: 1.07-5.33, P = 0.033). Only three (2.9%) procedures resulted in complications and required ventilator support and/or oxygen escalation.

Conclusions: BAL is a safe clinical tool that can be useful in impacting clinical management in a significant proportion of immunocompromised patients with pulmonary infiltrates.