The Diagnostic Utility of Bronchoscopic Biopsy and Tissue Culture in Lower Respiratory Infections

Abstract

Our objectives were (a) to determine if routinely sending bronchoscopic biopsy (BB) for histopathology (HP) and tissue culture (CUL) increases the diagnostic yield over that obtained by bronchoalveolar lavage (BAD) and protected specimen brush (PSB), (b) to identify subsets of patients who benefit from BB (CUL), and (c) to assess the morbidity associated with BB for suspected lower respiratory infection. We used a prospective design in a single tertiary care center. Our study patients were consecutive (N = 45) inpatients or outpatients with presumed lower respiratory infection in whom a BAL. PSB, and BB were planned as the standard of care. BAL, PSB, and BB specimens were obtained from each patient by flexible bronchoscopy. The initial two BB pieces were sent for BB (CUL) and subsequent specimens (three to six) were sent for routine BB (HP) analysis. Infectious pneumonia was identified in 34 (76%) study patients. Pathogens identified were cytomegalovirus (10), bacterial (10), Pneumocystis carinii (9), mycobacterial (3), fungi (1), and respiratory syncytial virus (1). BB (CUL) solely identified only one additional pathogen. However, BB (HP) provided additional diagnostic information over BAL and PSB in 13 of 45 (29%) patients. The addition of BB (HP) to BAL and PSB significantly increased the yield for making a specific diagnosis (either infectious or noninfectious) compared to BAL and PSB alone (p < 0.004). BB (HP) increased the diagnostic yield among patients with diffuse pulmonary infiltrates (p = 0.03). Pneumothorax (N = 3) and mild bleeding (N = 3) were the complications of biopsy. Our conclusions were as follows: (a) BB (HP) in addition to BAL and PSB significantly increased the likelihood for making a specific diagnosis (infectious or noninfectious) compared to BAL and PSB alone, especially among patients with diffuse pulmonary infiltrates: (b) routine CUL of BB had a limited incremental yield; and (c) sending BB routinely for both CUL and HP may be associated with a slight increase in morbidity.