Ventilator-associated pneumonia (VAP) is the most frequent infection among patients hospitalized in intensive care units, maintaining a high morbidity and mortality. The global incidence of VAP ranges from 8 to 28%. Early-onset VAP is mainly caused by community pathogens with a favorable pattern of antibiotic sensitivity, whereas late-onset VAP is often caused by multidrug-resistant pathogens, mainly methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter spp. and enteric Gram-negative bacilli. The diagnosis of VAP remains difficult to confirm, lacking both microbiological analysis and radiological signs of high specificity. The Clinical Infection Pulmonary Score has been proposed to overcome the difficulties related to the diagnosis, but is not applicable to all patient categories. A continuous evaluation of the antimicrobial therapeutic options, along with their pharmacodynamic and pharmacokinetic profiles, is mandatory to create therapeutic protocols and reduce VAP-related mortality
