CONCLUSIONS The most common organism responsible for VAP in this study was Pseudomonas aeruginosa. Negative ETA culture rules out the diagnosis of VAP. Quantitative cultures of BBS and blind BAL were useful in the diagnosis of VAP at threshold of ≥ 104 cfu / mL and ≥ 103 cfu / mL respectively. The role of BBS should be reevaluated in the future studies since it is cheap, easy to perform, well tolerated by ventilated children and can be repeated easily.