Ventilator Associated Pneumonia: Evolving Definitions and Preventive Strategies

作者：Cristina Mietto, Riccardo Pinciroli, Niti G. Patel, Lorenzo M. Berra · 发表于：Respiratory Care · 年份：2013 · DOI：10.4187/respcare.02380 · 被引用次数：157 · 研究领域：Nosocomial Infections in ICU、Pneumonia and Respiratory Infections、Inhalation and Respiratory Drug Delivery

Ventilator-associated pneumonia (VAP) is one of the most frequent hospital-acquired infections occurring in intubated patients. Because VAP is associated with higher mortality, morbidity, and costs, there is a need to solicit further research for effective preventive measures. VAP has been proposed as an indicator of quality of care. Clinical diagnosis has been criticized to have poor accuracy and reliability. Thus, the Centers for Disease Control and Prevention has introduced a new definition based upon objective and recordable data. Institutions are nowadays reporting a VAP zero rate in surveillance programs, which is in discrepancy with clinical data. This reduction has been highlighted in epidemiological studies, but it can only be attributed to a difference in patient selection, since no additional intervention has been taken to modify pathogenic mechanisms in these studies. The principal determinant of VAP development is the presence of the endotracheal tube (ETT). Contaminated oropharyngeal secretions pool over the ETT cuff and subsequently leak down to the lungs through a hydrostatic gradient. Impairment of mucociliary motility and cough reflex cannot counterbalance with a proper clearance of secretions. Lastly, biofilm develops on the inner ETT surface and acts as a reservoir for microorganism inoculum to the lungs. New preventive strategies are focused on the improvement of secretions drainage and prevention of bacterial colonization. The influence of gravity on muc...