From 10 to 25 percent of critically ill patients develop pneumonia severe enough to require mechanical ventilation. Colonization of the oropharynx and the stomach with potentially pathogenic organisms precedes the development of ventilator-associated pneumonia in most patients, probably due to microaspiration of oropharyngeal or gastric secretions contaminated with these organisms. Following a systematic review of studies on methods to prevent ventilatory-associated pneumonia, researchers at the University of California, San Francisco-Stanford University Evidence-based Practice Center (EPC) found strong evidence that several hospital practices could help to prevent this serious problem. The EPC is supported by the Agency for Healthcare Research and Quality (contract 290-97-0013).
All eligible patients should be put in a semi-recumbent position to reduce risk for gastroesophageal reflux and aspiration. Sucralfate rather than H2-antagonists should be used to prevent stress ulcers in patients at low to moderate risk for gastrointestinal tract bleeding. H2-antagonists and antacids may increase gastric pathogenic organisms, since these organisms increase with decreasing gastric acidity, and thus increase the risk for ventilator-associated pneumonia. Sucralfate, an alternative prophylactic agent that does not affect gastric pH, may not increase this risk.
Subglottic secretions should be aspirated to prevent their accumulation above the endotracheal tube cuff where they can contribute to the risk of aspiration, particularly in patients requiring more than 3 days of mechanical ventilation. Oscillating beds for surgical patients or patients with neurologic problems can minimize their immobility. This helps, since immobility impairs clearance of bronchopulmonary secretions that increase the risk for ventilator-associated pneumonia. Selective digestive tract decontamination is not recommended because routine use may increase antimicrobial resistance.
For more information, see "Prevention of ventilator-associated pneumonia: An evidence-based systematic review," by Harold R. Collard, M.D., Sanjay Saint, M.D., M.P.H., and Michael A. Matthay, M.D., in the March 2003 Annals of Internal Medicine 138(6), pp. 494-501.
Editor's Note: Copies of AHRQ Evidence Report/Technology Assessment No. 43, Making Health Care Safer: A Critical Analysis of Patient Safety Practices (AHRQ Publication No. 01-E058, full report, and 01-E057, summary), Shojania, K.G., Duncan, B.W., McDonald, K.M., and Wachter, R.M., editors, are available from the AHRQ Publications Clearinghouse.
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