the bacteremia may be from a source other than the lung infection. Prevention Prevention of VAP involves limiting exposure to resistant bacteria, discontinuing mechanical ventilation as soon as possible, and a variety of strategies to limit infection while intubated. Resistant bacteria are spread in much the same ways as any communicable disease. Proper hand washing, sterile technique for invasive procedures, and isolation of individuals with known resistant organisms are all mandatory for effective infection control. A variety of aggressive weaning protocols to limit the amount of time a person spends intubated have been proposed. One important aspect is limiting the amount of sedation that a ventilated person receives. Weak evidence suggests that raising the head of the bed to at least 30 degrees may help prevent VAP, however further research is required to understand the risks associated with this. Antiseptic mouthwashes (in particular associated with toothbrushing) such as chlorhexidine may also reduce the risk of VAP, although the evidence is mainly restricted to those who have undergone cardiac surgery. American and Canadian guidelines strongly recommend the use of subglottic secretion drainage (SSD). Special tracheal tubes with an incorporated suction lumen as the EVAC tracheal tube form Covidien / Mallinckrodt can be used for that reason. New cuff technology based on polyurethane material in combination with subglottic drainage (SealGuard Evac tracheal tube from Covidien / Mallinckrodt) showed significant delay in early and late onset of VAP. There is little evidence that the use of silver-coated endotracheal tubes reduces the incidence of VAP in the first ten days of ventilation. There is tentative evidence that the use of probiotics may reduced the likelihood of getting VAP, however it is unclear if probiotics affect ICU or in-hospital death. Treatment Treatment of VAP should be matched to known causative bacteria. However, when VAP is first suspected, the bacteria causing infection is typically not known and broad-spectrum antibiotics are given (empiric therapy) until the particular bacterium and its sensitivities are determined. Empiric antibiotics should take into account both the risk factors a particular individual has for resistant bacteria as well as the local prevalence of resistant microorganisms. If a person has previously had episodes of pneumonia, information may be available about prior causative bacteria. The choice of initial therapy is therefore entirely dependent on knowledge of local flora and will vary from hospital to hospital. Treatment of VAP with a single antibiotic has been reported