Pneumonie associée à la ventilation mécanique

Ventilator-associated pneumonia (VAP) is the most common hospital-acquired infection in the intensive care unit. Its onset occurs, by definition, after more than 48 hours of non-invasive or invasive mechanical ventilation. Mortality of patients developing VAP is high (20%) and VAP prolongs the duration of mechanical ventilation and intensive care unit length of stay. The most common bacteria are Enterobacteriaceae, Pseudomonas aeruginosa, and Staphylococcus aureus. The infection is polymicrobial in one third of the cases and bacteria are commonly resistant to antibiotics, particularly if the duration of mechanical ventilation is prolonged over 5 days. Diagnosis of VAP is difficult because clinical signs are not specific nor sensitive and microbiological documentation remains essential in this setting. Broad-spectrum empiric antimicrobial therapy must be started as soon as possible after microbiological sampling, in particular in the presence of severity signs or in patients at risk, and secondarily adapted to definite microbiological results. The choice of the initial antimicrobial therapy must consider risk factors of bacterial resistance or non-fermenting GNB-related infection. The recommended duration of the antimicrobial treatment is 7 days, with some exceptions. Prevention is based on standardized protocols including various measures. In this concern, the selective digestive decontamination has been deemed efficient in environments with low prevalence of multidrug resistant bacteria.