Evidence-based practice: use of the ventilator bundle to prevent ventilator-associated pneumonia

American Journal of Critical Care, Jan, 2007 by Arlene F. Tolentino-DelosReyes, Susan D Ruppert, Shyang-Yun Pamela K. Shiao

* PURPOSE To examine critical care nurses' knowledge about the use of the ventilator bundle to prevent ventilator-associated pneumonia.

* METHOD Published reports were reviewed for current evidence on the use of the ventilator bundle to prevent ventilator-associated pneumonia, and education sessions were held to present the findings to 61 nurses in coronary care and surgical intensive care units. Changes in the nurses' knowledge were evaluated by using a 10-item test, given both before and after the sessions. Changes in the nurses 'practices related to ventilator-associated pneumonia, including elevation of the head of the bed to 30[degrees] to 45[degrees] were observed in 99 intubated patients.

* RESULTS After the education sessions, the nurses performed better on 8 of the 10 items tested (P from .03 to <.001). The areas of most significant improvement were elevation of the head of the bed (P < .001), charting of the elevation of the head of the bed (P = .009), oral care (P = .009), checking of the nasogastric tube for residual volume (P = .008), washing of hands before contact with patients (P <.001), and limiting the wearing of rings (P < .001) and nail polish (P = .04). Even after the education sessions, the nurses' compliance with hand-washing recommendations before contact with patients was low, though statistically some improvement was apparent. Contraindications to elevation of the head of the bed did not appear to affect the nurses 'practices (P = .38).

* CONCLUSION Education sessions designed to inform nurses about the ventilator bundle and its use to prevent ventilator-associated pneumonia have a significant effect on participants' knowledge and subsequent clinical practice.

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Ventilator-associated pneumonia (VAP) is an important safety issue in critically ill patients and in patients receiving mechanical ventilation. The American Association of Critical-Care Nurses (AACN) recommended steps for reducing the incidence of VAP; these steps are based on the best-practice guidelines for patients receiving mechanical ventilation. Called the "ventilator bundle," these steps incorporate the following guidelines from the Centers for Disease Control and Prevention (CDC) for preventing nosocomial pneumonia (1,2):

* elevation of the head of the bed (HOB) to 30[degrees] to 45[degrees] unless medically contraindicated,

* continuous removal of subglottic secretions,

* change of ventilator circuit no more often than every 48 hours, and

* washing of hands before and after contact with each patient.

These steps are considered feasible, safe, and cost effective for preventing VAP.

The CDC has not offered any recommendations about oral care or about how often to check the residual volume in nasogastric tubes. Nor has it suggested modifications in tube feeding procedures to prevent VAP, such as suspending feedings while patients are being repositioned or turning patients supine before commencing feedings. Research is still needed to ascertain at what level gastric residual volume increases aspiration risk and at what level feedings should be withheld. More research is needed on oral care and on procedures for checking residual volume in nasogastric tubes.

Current best practices for patients at risk of VAP can be established by conducting systematic literature reviews on the ventilator bundle and factors related to VAP and by communicating evidence-based findings through education sessions. Supported by current research and scientific evidence, this clinical project was aimed at examining critical care nurses' knowledge of the ventilator bundle and its applications for preventing VAP.

Current Evidence About the Ventilator Bundle and VAP

Most published studies have focused on the relationship between HOB elevation and the incidence of VAP. Table 1 presents current evidence on the prevention of VAE with respect to HOB elevation, hand washing, and oral care. A significant relationship between HOB elevation to 30[degrees] to 45[degrees] and a reduced incidence of VAP has been reported. (3,5,9)

Factors affecting the incidence of VAP include early, low back-rest elevation and severity of illness; backrest elevation alone has no relationship to the Clinical Pulmonary Infection Score. (6) In addition, high acuity levels with higher scores on the Acute Physiology and Chronic Health Evaluation II were directly associated with development of VAP, (3,4,6) and patients with VAP had higher mortality rates. (4) In a replication study, (8) the mean observed HOB position was 23[degrees] for intubated patients and 38[degrees] for nonintubated patients (P < .001). Kollef et al (5) reported that patients transported out of the intensive care unit (ICU) are at greater risk for development of VAE

Other researchers explored the barriers to using HOB elevation as a method of preventing VAP (14) and examined the relationship between VAP, days of mechanical ventilation, and ICU days, and thus hospital cost. (13) These researchers concluded with a recommendation that the HOB be elevated to 30[degrees] to 45[degrees] in patients receiving mechanical ventilation unless doing so is medically contraindicated. Babcock et al (10) reported a decrease in the rate of VAP after an educational intervention (from 8.75 cases per 1000 ventilator days before to 4.74 cases per 1000 ventilator days after; P<.001). Results of other studies (11,12) confirmed that staff education decreased the incidence of VAP (46% to 57.6%, P values from <.001 to .02).