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tion Evidence-based strategies to prevent

ventilator-associated pneumonia By Amy Shay, MS, RN, CNS

12 American Nurse Today Volume 10, Number 9 www.AmericanNurseToday.com

Defined as pneumonia thatdevelops within 48 of endo-tracheal intubation, venti-

lator-associated pneumonia(VAP) is the most common hospi-tal-acquired infection in criticalcare units. It leads to longer in-tensive-care stays, increased me-chanical ventilation time, greatermortality, and higher costs.

Although VAP incidence in theUnited States has declined to 0.0to 4.4 cases per 1,000 patientdays, it remains a concern. Pre-vention strategies focus on threecausative mechanisms—bacterialcolonization of the respiratoryand upper GI tracts, aspirationof contaminated secretions, andcontamined respiratory equip-ment. Understanding evidence-based strategies can help you re-duce your patients’ VAP risk.

Recognized evidence-basedstrategies Several professional organiza-tions have developed or endorsedevidence-based guidelines forVAP prevention. Here are four ofthe most commonly recommend-ed strategies.

Use an endotracheal tubewith a lumen for continuoussuction of subglotticsecretions.

Contaminated secretions poolabove the endotracheal tube cuffand migrate into the lungs evenwith a properly inflated cuff.Continuous removal of these se-cretions by suctioning reduces as-piration risk. Endotracheal tubeswith a continuous subglottic suc-tion lumen are linked to re-duced VAP rates and decreased

duration of mechanical ventila-tion in patients who need morethan 48 hours of ventilation.

Keep the head of the bedelevated 30 to 45 degrees.

Unless medically contraindicated,keep the head of the bed elevatedfor patients with a high aspira-tion risk, including those who areon mechanical ventilation orhave an enteral feeding tube.Supine positioning is linked tohigher bacterial counts in aspirat-ed secretions than semirecumbentpositioning. Use the bed’s angle-indication device to ensure an ac-curate elevation angle; nurses’ es-timates of the angle have beenshown to be inaccurate.

Commit to an oral careprotocol using chlorhexidine.

Within 48 hours of hospitaliza-tion, the oral flora of critically illpatients changes to include poten-tial respiratory pathogens rarelyfound in healthy persons. The en-dotracheal tube provides a migra-tion route for organisms to travelto the lungs. Oral hygiene proto-cols with chlorhexidine help com-bat colonization of the respiratory

tract and reduce dental plaque(which acts as a bacterial reser-voir). Although chlorhexidine0.12% solution is the most com-monly used concentration, no firm consensus exists for themost effective concentration. Thestrongest evidence for chlorhexi-dine has been reported in the car-diac surgery population, althoughmany hospitals regularly use it fornoncardiac surgical patients.

Change the ventilator circuitonly when visibly soiled.

Studies evaluating contaminatedventilator circuits show thatchanging circuits more oftendoesn’t reduce pneumonia inci-dence. In fact, changing circuitsless often may reduce exposureto infectious aerosols. Before pa-tient repositioning, drain thecondensation in circuits awayfrom the patient. For details ondisinfecting and sterilizing respi-ratory equipment, visit www.cdc.gov/mmwr/preview/mmwrhtml/rr5303a1.htm.

Other best practices The practices described below arerecommended for VAP by at leastone professional organization,although they’re not cited as of-ten as the above interventions.

Use NIPPV to avoid intubation or reintubation.

Noninvasive positive pressureventilation (NIPPV) can be a use-ful alternative to mechanical ven-tilation. It has been particularlyeffective in avoiding the need forintubation in patients who are inthe acute phase of chronic ob-

This multifacetedhospital-acquired

infection calls for amultidirectional

solution. —

structive pulmonary disease orheart-failure exacerbation. NIPPValso can be used during weaningto shorten duration of intubation(unless contraindicated).

Use effective weaning strategies to reduce mechanical ventilation days.

Because VAP risk rises 1% to 3%every day the patient remains onmechanical ventilation, effectivestrategies to promote weaningcan indirectly lower the risk.Nurse- or therapist-driven wean-ing protocols that include dailyassessment for readiness to weanlead to shorter mechanical venti-lation periods.

Additional emerging strategiescoordinate sedation cessationwith spontaneous breathing tri-als and include early mobilityand delirium assessment to pro-mote freedom from the ventila-tor. The American Association ofCritical-Care Nurses (AACN) in-troduced the evidence-basedABCDE bundle as an organiza-tional approach to coordinatingthese complex multidisciplinaryweaning efforts. ABCDE standsfor Awakening and BreathingCoordination, Delirium Monitor-ing and Management, and EarlyMobility.

Avoid nasotracheal intubation.

Nasal obstruction with an endo-tracheal tube (or feeding tube)can prevent clearing of sinusdrainage, leading to hospital-ac-quired sinusitis and aspiration ofcontaminated secretions. Whenpossible, avoid nasotracheal in-tubation.

Potentially effectivestrategies Silver-coated endotracheal tubesand kinetic beds aren’t recom-mended by any organization,but some supporting evidencesuggests these strategies may beeffective.

Use silver-coated endotracheal tubes.

Soon after intubation, endotra-cheal-tube surfaces become coat-ed with a bacterial biofilm. Sil-ver-coated tubes provide antibac-terial properties and discouragebacterial adherence, leading todelayed colonization and de-layed VAP. Expert opinions onsilver-coated endotracheal tubesvary, ranging from “suitable foruse” to “additional studies areneeded” to “generally not recom-mended.”

Use kinetic beds.

One meta-analysis found thatcontinuous lateral rotation viathe kinetic bed led to reduced VAPrates. However, VAP preventionguidelines rarely include this in-tervention. The kinetic bed re-mains “generally not recom-mended” by The Society forHealthcare Epidemiology ofAmerica, while the Institute forClinical Systems Improvementstates the bed is “not recommend-ed for routine use.” Rationales fornot using the bed include lack ofpositive impact on death ratesand ventilation duration; also,

this bed isn’t available in somehealthcare organizations.

Multifaceted problem,multidirectional solution VAP is a multifaceted problem thatcalls for a multidirectional solu-tion. Successful VAP preventionstrategies require interdisciplinarycooperation, education, and moni-toring of guideline adherence. Thecomplexity of prevention interven-tions can make protocol compli-ance challenging; healthcare facil-ities may want to group small setsof evidence-based interventions to-gether for easier implementation.Bundling interventions has beenshown to promote changes inhealthcare professionals’ practiceswhile providing a useful frame-work for measuring and reportingcompliance. (See Nursing practicesthat help prevent VAP.)

For resources on implementingVAP prevention and ventilatorweaning strategies, visit the AACNwebsite (www.aacn.org). �

Visit www.AmericanNurseToday.com/

Archives.aspx for a list of selected references.

Amy Shay is an assistant professor of clinical at theUniversity of Cincinnati College of Nursing inCincinnati, Ohio, and is on the nursing staff at MiamiValley Hospital in Dayton, Ohio.

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www.AmericanNurseToday.com September 2015 American Nurse Today 13

Nursing practices that help prevent VAP Several basic nursing practices contribute to successful efforts to preventventilator-associated pneumonia (VAP).

Practice proper hand hygiene.The Association for Professionals in Infection Control and Epidemiology and theCenters for Disease Control and Prevention (CDC) remind practitioners thatadhering to hand hygiene protocol is essential to prevent transmission ofbacteria when caring for mechanically ventilated patients. CDC recommendswearing gloves when handling respiratory secretions and for contact withobjects contaminated by respiratory secretions.

Verify feeding-tube placement and take steps to prevent aspiration.Routinely verify proper feeding-tube placement. To help prevent aspirationassociated with enteral feedings, monitor gastric residual volume and assess forsigns and symptoms of gastric overdistention.

Routinely verify endotracheal tube cuff pressure.Measure endotracheal tube cuff pressure directly; maintain pressure between 20and 25 cm H2O. Properly inflated cuff pressure helps prevent microaspiration,VAP, and tracheal injury.