Clinical utility of bronchoalveolar lavage in immunocompromised patients with pulmonary infiltrates: impact on diagnostic yield and management

Abstract Background Pulmonary infiltrates in immunocompromised patients are associated with high morbidity and mortality, and accurate diagnosis is often challenging due to overlapping infectious and non‐infectious aetiologies. Flexible bronchoscopy with bronchoalveolar lavage (BAL) is widely used, but its contemporary real‐world clinical utility across heterogeneous immunocompromised populations remains uncertain. Aims To retrospectively evaluate the clinical utility of inpatient flexible bronchoscopy with BAL in immunocompromised adults presenting with new pulmonary infiltrates at a tertiary referral centre. Methods Retrospective cohort study conducted at a Victorian tertiary centre including immunocompromised adults who underwent inpatient flexible bronchoscopy for new CT‐confirmed pulmonary infiltrates between January 2022 and December 2024. The primary outcomes were diagnostic yield and the proportion of procedures resulting in a change in clinical management. Results Sixty‐two patients were included (mean age 60.3 ± 16.9 years; 38.7% female). Patients with underlying haematological malignancy accounted for 59.7% of cases, and 83.9% were receiving empiric antibiotic therapy prior to bronchoscopy. Overall diagnostic yield was 43.5% (27/62). Bronchoscopy resulted in a change in clinical management in 64.5% of cases (40/62), most commonly initiation of targeted antimicrobial therapy (47.5%). The median interval from imaging to bronchoscopy was 4.5 days. Procedural complications were uncommon and limited (4.8%). Patients with haematological malignancy had higher odds of fungal infection (OR 6.81, 95% CI 1.33–68.54; P = 0.009) and mortality at 12 months (51.4% vs 20.0%; OR 4.22, CI 1.17–17.16, P = 0.017) compared to non‐haematological causes of immunocompromise. Conclusion In immunocompromised inpatients with pulmonary infiltrates, bronchoscopy with BAL was associated with frequent changes in clinical management and a low rate of procedure‐related complications. These observational findings support its use in appropriately selected patients, while prospective studies are needed to determine its effect on patient‐centred outcomes.