Comparative Evaluation of the Role of Nonbronchoscopic and Bronchoscopic Techniques of Distal Airway Sampling for the Diagnosis of Ventilator-Associated Pneumonia

BACKGROUND: The diagnosis of ventilator-associated pneumonia (VAP) remains a challenge, with clinicians mainly relying on clinical, radiological, and bacteriologic strategies to manage patients with VAP. AIMS: To compare the results of non-bronchoscopic and bronchoscopic techniques of distal airway sampling for the diagnosis of VAP. SETTINGS AND DESIGN: This was a single-center prospective diagnostic accuracy study done in the 14-bedded intensive care unit of a tertiary care referral hospital. MATERIALS AND METHODS: Patients aged ≥18 years, on mechanical ventilation for ≥48 h, and with clinical suspicion of VAP (fever, leukocytosis, and increased tracheal secretions) either on admission or during their stay were included. Every patient underwent both procedures for sample collection, first non-bronchoscopic protected bronchoalveolar lavage (NP-BAL) and then bronchoscopic BAL (B-BAL). Clinical Pulmonary Infection Score (CPIS) was calculated for each patient and the collected samples were evaluated in laboratory using standard microbiological techniques. STATISTICAL ANALYSIS USED: The sensitivity, specificity, positive predictive value, and negative predictive value of NP-BAL and B-BAL for the diagnosis of VAP were calculated taking CPIS score of >6 as index test for the diagnosis of VAP. RESULTS: Sixty patients were included in the study. Both NP-BAL and B-BAL had concordance with the CPIS at 69.1%. The concordance between NP-BAL and B-BAL was better at 67.6% with a kappa coefficient of 0.064 (P = −0.593). The yield and sensitivity of NP-BAL were comparable to that of B-BAL. CONCLUSIONS: The blind NP-BAL is an equally effective method of airway sampling and could be a better alternative to replace more invasive B-BAL for microbiologic diagnosis of VAP.