Agreement Between Quantitative Cultures of Postintubation Tracheal Aspiration and Plugged Telescoping Catheter, Protected Specimen Brush, or BAL for the Diagnosis of Nosocomial Pneumonia

Background The diagnosis of ventilator-associated pneumonia relies on protected specimen brush (PSB), BAL, and plugged telescoping catheter (PTC) procedures. In the particular setting of nosocomial pneumonia (NP) occurring in non-mechanically ventilated patients, no consensus exists on their use. When mechanical ventilation (MV) becomes mandatory, postintubation tracheal aspiration (PITA) could be a simple, fast, and cheap diagnostic tool. Our aim was to compare the diagnostic accuracy of PITA to that of PSB, BAL, or PTC in patients requiring MV for suspected NP. Methods Patients with a prior hospital stay of ≥ 48 h who required MV for suspicion of NP were prospectively enrolled in the study. PITA was performed by sterile suction. Within 2 h, pulmonary samples were obtained by PSB, BAL, or blinded PTC, which are referred to hereafter as "reference methods" (RMs). The definite diagnosis of NP was made using a composite item of clinical, radiologic, and bacteriologic ( ie , blood or pleural fluid cultures) patterns. The agreement between the quantitative microbiological results obtained with PITA and those of the RMs was assessed by the κ-statistic. The sensitivity, specificity, and positive and negative likelihood ratios of PITA and RMs were calculated taking the definite diagnosis of NP as the reference. Results There were 44 cases (63.8%) of confirmed NP. The κ-statistic was 0.71. The sensitivity, specificity, and positive and negative likelihood ratios were 77%, 84%, 4.80, and 0.27, respectively, for PITA, and 75%, 88%, 6.25, and 0.28, respectively, for RMs. Conclusions PITA may be a reliable alternative to RMs in the particular setting of NP in newly mechanically ventilated patients.