Bronchoscopic bronchoalveolar lavage. Before starting BAL, all patients were pre-oxygenated with 100% oxygen for 5-10 minutes. The site for bronchoscopic BAL was chosen according to the x-ay appearance. BAL was thus performed in an area of localized pulmonary infiltration if present. In case the chest x-ray showed diffuse disease or no specific area with infiltrate, BAL was performed in the area with most inflammation or with purulent secretions. If no inflammation or purulent secretions were seen during bronchoscopy, BAL was performed in the right lower or middle lobe. All bronchoscopic lavages were obtained with Olympus BF type XP40 bronchoscope (Olympus Optical Co. Japan) with outer diameter of 2.8mm and a suction channel of 1.2mm size. Endotracheal suction was done just prior to introduction of bronchoscope. Lignocaine spray was avoided as local anesthetic during the procedure. BAL was performed via the endotracheal tube using a swivel adapter. In infants with 4.5 or less endotracheal tube size, an appropriate size laryngeal airway mask was used for bronchoscopic lavage (24). Under visual control, the bronchoscope was advanced in the direction of the chosen segment until a wedged position was achieved. Lavage was carried out using 4 aliquots of sterile saline (depending on weight of the patient)