Culturing bronchial washings obtained during bronchoscopy fails to add diagnostic utility to culturing the bronchoalveolar lavage fluid alone

A retrospective analysis was performed to determine whether cultures of bronchial washings (BW) obtained during bronchoscopy added to the diagnostic efficiency of cultures of bronchoalveolar lavage fluid (BAL) alone. Results of BW and BAL cultures submitted from 268 patients over a 7-month period were compared. The isolation of an organism from the BW but not from the BAL occurred in only 17.4% of cases. Moreover, the vast majority of those organisms consisted of yeasts or molds of questionable clinical significance that did not prompt a change in antimicrobial therapy. Culturing the BAL specimen alone would have resulted in an efficiency of 97.0% (95% confidence interval 94.2-98.7%) for the isolation of clinically relevant pathogens identified from bronchoscopic specimens. These results suggest that the submission of BW obtained during the BAL procedure for culture evaluation not only fails to add diagnostic value, but may also result in unnecessary laboratory evaluations and provide misleading information to clinicians.