Detailed below are multiple patient care practices thought to reduce ventilator-associated pneumonia (VAP). Although several of these interventions have been independently shown to significantly reduce VAP rates, clinical experience suggests that using several of these interventions together can maximize VAP rate reductions.

• Head of the bed elevation
• CASS (continuous aspiration of subglottic secretions)
• Oral care
• Oral antiseptics
• Reduction in ventilator circuit changes
• Sedation interruption/extubation readiness assessments
• Stress ulcer prophylaxis

Head of the Bed Elevation

Description: Also known as semirecumbent positioning, this method is typically defined as raising the head of the bed to an angle of 30-45 degrees. This intervention is thought to reduce VAP by decreasing aspiration.

Evidence: One randomized controlled trial found a three-fold reduction in the VAP rate of patients managed in the semirecumbent position.¹ Additionally, several studies have found that head of the bed elevation reduces aspiration of enteral feeding solution compared with supine positioning.^2,3

Cost: None

Continuous Aspiration of Subglottic Secretions (CASS)

Description: Continuous aspiration of subglottic secretions is done with a specialized endotracheal tube with a separate dorsal lumen. CASS removes oral and/or gastric secretions from the subglottic space, preventing micro-aspiration that could lead to VAP.

Evidence: Four randomized clinical studies in patients expected to be intubated >72 hours found reductions in VAP rates of up to 59%.^4-7 A meta-analysis of these studies found that CASS reduces VAP by nearly half, reduces ICU length of stay by 3 days, reduces duration of mechanical ventilation by 2 days and delays the onset of VAP by 6.9 days.⁸ A fifth study in post-cardiac patients intubated an average of 1.5 days did not find a significant reduction in VAP.⁹

Cost: $13 - $15 per intubated patient

Oral Care

Description: Oral care protocols vary, but typically oral care is performed every two to four hours and includes swabbing and/or brushing the teeth and oral cavity, suctioning oral secretions, applying mouth moisturizer and/or treating with oral chlorhexidine rinse (see “Oral Antiseptics”).

Evidence: One nonrandomized study found a 63% reduction in VAP rates compared with historical control subjects.¹⁰

Cost: Varies depending on protocols and products used; typically $15-$30 per day. Significant labor costs.

Oral Antiseptics

Description: Oral chlorhexidine rinse or other topical antiseptics are applied 2-3 times daily to the oral cavity to control colonization of the oropharynx.

Evidence: An initial study in cardiac surgery patients found a reduction in overall respiratory tract infections,¹¹ but the results could not be confirmed in later studies. As a result, most guidelines limit use of chlorhexidine rinse to cardiac surgery patients. A recent double-blind, randomized trial found 65% VAP risk reduction with chlorhexidine paste and 55% VAP risk reduction with combined chlorhexidine-colistin paste.¹²

Cost: Minimal product cost, some labor cost

Reduction in Ventilator Circuit Changes

Description: Most guidelines now recommend changing ventilator circuits only when they are visibly soiled or malfunctioning, rather than based on duration of use.

Evidence: Several observational and randomized studies have found no correlation between frequency of ventilator circuit changes and rates of nosocomial pneumonia.

Cost: Cost savings compared to regular circuit replacement

Sedation Interruption/Extubation Readiness Assessments and Weaning Protocols

Description: These interventions are intended to reduce duration of mechanical ventilation and the associated risk for VAP. Sedation "vacations" involve daily lightening of sedation to assess neurological readiness for ventilator weaning and extubation. An alternative is assessing patients for ventilator weaning readiness when they meet specific criteria as determined in weaning protocols. Sedation lightening is often a component of ventilator weaning protocols.

Evidence: Several studies have found an association between duration of mechanical ventilation and development of VAP, so strategies that reduce the duration of mechanical ventilation should reduce VAP. One randomized study found that daily interruption of sedation reduced the duration of mechanical ventilation from 7.3 days to 4.8 days, with an associated reduction in complications.¹³

Cost: No direct costs; significant labor costs for assessments

Stress Ulcer Prophylaxis

Description: Preferential use of histamine type-2 (H₂) antagonists vs. sucralfate to prevent stress ulcers is controversial. Both H₂ antagonists and antacids have been identified as risk factors for VAP because they decrease intragastric acidity, which can result in greater colonization of pathogenic bacteria. Sucralfate does not decrease gastric acidity or significantly increase gastric volume, but it appears less effective in reducing gastric bleeding. The American Thoracic Society guidelines state: “If stress ulcer prophylaxis is indicated, the risks and benefits of each regimen should be weighed before prescribing either H₂ blockers or sucralfate.

Evidence: One large trial comparing sucralfate with ranitidine found a trend toward lower VAP rates with sucralfate, but a somewhat higher incidence of gastrointestinal bleeding.¹⁴ A multicenter trial of ARDS patients found an association between sucralfate use and increased VAP risk.¹⁵

Cost: Minimal cost, varies by type of medication

1. Drakulovic MB, Torres A, Bauer TT, Nicolas JM et al. Supine body position as a risk factor for nosocomial pneumonia in mechanically ventilated patients: a randomized trial. Lancet. 1999;354:1851-1858.
2. Orozco-Levi M, Torres A, Ferrer M, Piera C, et al. Semirecumbent position protects from pulmonary aspiration but not completely from gastroesophageal reflux in mechanically ventilated patients. American Journal of Respiratory Critical Care Medicine. 1995;152:1387-1390.
3. Torres A, Serra-Batlles J, Ros E, Piera C et al. Pulmonary aspiration of gastric contents in patients receiving mechanical ventilation: the effect of body position. Annals of Internal Medicine. 1992;116:540-543.
4. Smulders K, van der Hoeven H, Weers-Pothoff I, Vandenbroucke-Grauls, C. A randomized clinical trial of intermittent subglottic secretion drainage in patients receiving mechanical ventilation. Chest. 2002;121:858-862.
5. Bo H, He L, Qu J. Influence of the subglottic secretion drainage on the morbidity of ventilator-associated pneumonia in mechanically ventilated patients [in Chinese]. Zhonghua Jie He He Hu Xi Za Zhi. 2000;23:472–474.
6. Valles J, Artigas A, Rello J, et al. Continuous aspiration of subglottic secretions in preventing ventilator-associated pneumonia. Annals of Internal Medicine. 1995;122:179-186.
7. Mahul Ph, Auboyer C, Jospe R, et al. Prevention of nosocomial pneumonia in intubated patients: respective role of mechanical subglottic secretions drainage and stress ulcer prophylaxis. Intensive Care Medicine. 1992;18:20-25.
8. Dezfulian C, Shojania K, Collard H, et al. Subglottic secretion drainage for preventing ventilator-associated pneumonia: a meta-analysis. The American Journal of Medicine. 2005;118,11-18.
9. Kollef MH, Skubas NJ, Sundt TM. A randomized clinical trial of continuous aspiration of subglottic secretions in cardiac surgery patients. Chest. 1999;116:1339-1346.
10. Mori H, Hirasawa H, Oda S, et al. Oral care reduces incidence of ventilator-associated pneumonia in ICU populations. Intensive Care Medicine. 2006;15:1-7.
11. DeRiso AJ II, Ladowski JS, Dillon TA, Justice JW, Peterson AC. Chlorhexidine gluconate 0.12% oral rinse reduces the incidence of total nosocomial respiratory infection and nonprophylactic systemic antibiotic use in patients undergoing heart surgery. Chest. 1996;109:1556–1561.
12. Koeman M, van der Ven A, Hak E, et al. Oral decontamination with chlorhexidine reduces the incidence of ventilator-associated pneumonia: a randomized, placebo-controlled trial. Am J Respir Crit Care Med. 2006;173:1348–1355
13. Schweickert WD, Gehlbach BK, Pohlman AS, et al. Daily interruption of sedative infusions and complications of critical illness in mechanically ventilated patients. Crit Care Med. 2004;32:1272–1276
14. Cook D, Guyatt G, Marshall J, Leasa D, Fuller H, Hall R, Peters S, Rutledge F, Griffith L, McLellan A, et al., Canadian Critical Care Trials Group. A comparison of sucralfate and ranitidine for the prevention of upper gastrointestinal bleeding in patients requiring mechanical ventilation. N Engl J Med. 1998;338:791–797.
15. Prod’hom G, Leuenberger P, Koerfer J, Blum A, et al. Nosocomial pneumonia in mechanically ventilated patients receiving antacid, ranitidine, or sucralfate as prophylaxis for stress ulcer: a randomized controlled trial. Ann Intern Med. 1994;120:653–662.

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