Protected specimen brush or bronchoalveolar lavage to diagnose bacterial nosocomial pneumonia in ventilated adults: A meta-analysis

Objective: We conducted a meta-analysis by using summary receiver operating characteristic curves to compare the diagnostic value for bacterial nosoco mial pneumonia of the following: a) quantitative culture (colony-forming un its per milliliter or CFU/mL) of respiratory secretions collected with a br onchoscopic protected specimen brush (PSB); b) quantitative culture of a br onchoscopic bronchoalveolar lavage (BAL); and c) the percentage of infected cells (lc) in BAL. Data Sources: All studies published in the English or the French language, through January 1, 1995, on the evaluation of PSB or BAL for the diagnosis of pneumonia were considered for analysis, The relevant literature was iden tified through computer and reference searching and by experts in the field . Study Selection: A study was included if at least two of three independent readers regarded its purpose as the evaluation of CFU-PSB, CFU-BAL, or IC-B AL for the diagnosis in human beings of bacterial nosocomial pneumonia in v entilated adults and if the study was prospective and published in a peer-r eviewed journal, Data Extraction: Three readers reviewed all published articles and decided whether to include each study; consensus was defined as agreement by at lea st two readers. The authors of each original article included in the meta-a nalysis were asked to complete a questionnaire in which they were asked to check and to correct the data extracted by one of the independent readers. Data Synthesis: Summary receiver operating characteristic curves were used to compare the efficacy of three diagnostic tests. Eighteen studies an CFU- PSB (795 patients) were included, as well as 11 studies on CFU-BAL (435 pat ients) and 11 on IC-BAL (766 patients). The accuracy of these tests was not different, However, it seems that administration of previous antibiotics m arkedly decreased accuracy of CFU-PSB (p = .0002) but not the accuracy of C FU-BAL and that of IC-BAL. Conclusion: Both PSB and BAL are reliable to diagnose bacterial nosocomial pneumonia, Because CFU-BAL and IC-BAL seemed more resistant to the effects of antibiotics, we recommend BAL rather than PSB if the patient is already receiving antibiotics.