 The reported incidence of ventilator associated pneumonia VAP is 10 to 15 per 1,000 ventilator days. VAP leads to an excess cost exceeding 40,000 per patient and is associated with a crude mortality rate as high as 76. The clinical criteria for the diagnosis of VAP have low specificity and may lead to unnecessary antibiotic use. The Clinical Pulmonary Infection Score CPIS and bronchoscopic approaches lower unnecessary antimicrobial use, antimicrobial resistance, and superinfection compared to the traditional clinical criteria. 