VAP is directly linked to the aspiration of colonized secretions.
The oropharyngeal colonizing flora is often the source of the causative organisms of VAP.([FOOTNOTE=Garrouste-Orgeas M, Chevret S, Arlet G, et al. Oropharyngeal or gastric colonization and nosocomial pneumonia in adult intensive care unit patients. A prospective study based on genomic DNA analysis. Am J Respir Crit Care Med. 1997;156(5):1647-1655. [ View Abstract ]],[ANCHOR=],[LINK=])
Interventions that reduce oropharyngeal colonization reduce the incidence of VAP.([FOOTNOTE=Chlebicki MP, Safdar N. Topical chlorhexidine for prevention of ventilator-associated pneumonia: a meta-analysis. Crit Care Med. 2007;35(2):595-602. [ View Abstract ]],[ANCHOR=],[LINK=])
The sequence of colonization in patients undergoing mechanical ventilation is the oropharynx (36 h), the stomach (36-60 h), the lower respiratory tract (60-84 h) and thereafter the endotracheal tube (60-96 h)([FOOTNOTE=Feldman C, Kassel M, Cantrell J, et al. The presence and sequence of endotracheal tube colonization in patients undergoing mechanical ventilation. Eur Respir J. 1999;13(3):546-551. [ View Abstract ]],[ANCHOR=],[LINK=])
While microaspiration of contaminated secretion is the primary pathway for VAP, biofilm on the endotracheal tube may play a role in maintaining the infection.([FOOTNOTE=Deem S, Treggiari MM. New endotracheal tubes designed to prevent ventilator-associated pneumonia: do they make a difference? Respir Care. 2010;55(8):1046-1055. [ View Abstract ]],[ANCHOR=],[LINK=])
Bibliography of VAP Evidence
View a list of studies used on this site.
VAP Fact Sheet
Learn more about VAP and guidelines for its prevention.
The major source of infection may be contaminated oropharyngeal secretions that leak through folds of the inflated ETT cuff.([FOOTNOTE=Cardenosa Cendrero JA, Sole-Violan J, Bordes Benitez A, et al. Role of different routes of tracheal colonization in the development of pneumonia in patients receiving mechanical ventilation. Chest. 1999;116(2):462-470. [ View Abstract ]],[ANCHOR=],[LINK=]),([FOOTNOTE=Blunt MC, Young PJ, Patil A, Haddock A. Gel lubrication of the tracheal tube cuff reduces pulmonary aspiration. Anesthesiology. 2001;95(2):377-381. [ View Abstract ]],[ANCHOR=],[LINK=])
Microaspiration occurs in virtually 100 percent of inflated high-volume, low-pressure ETT cuffs.6
Microaspiration is reduced but still present in the semirecumbent position compared to the supine position.([FOOTNOTE=Orozco-Levi M, Torres A, Ferrer M, et al. Semirecumbent position protects from pulmonary aspiration but not completely from gastroesophageal reflux in mechanically ventilated patients. Am J Respir Crit Care Med. 1995;152(4 Pt 1):1387-1390. [ View Abstract ]],[ANCHOR=],[LINK=])