VAP bundles (Table 4-1) are used for prevention. The use of a bundle recognizes that a combination of strategies is more effective than a single strategy for VAP prevention.
Table 4-1Elements Commonly Included in a VAP Prevention Bundle ||Download (.pdf) Table 4-1 Elements Commonly Included in a VAP Prevention Bundle
• Appropriate hand hygiene.
• Precautions based on specific infection.
• Use noninvasive ventilation.
• Head elevated > 30 degrees.
• Routine oral care.
• Use cuff pressure of 20-30 cm H2O.
• Use inline suction catheters.
• Do no routinely change ventilator circuits.
• Remove ventilator circuit condensate away from the patient.
• Use orotracheal instead of nasotracheal intubation.
• Use subglottic suction systems and cuffs that minimize aspiration.
• Rinse nebulizers with sterile water (or saline) between treatments and allow to air dry.
• Deliver aerosolized medications using methods that do not break the circuit.
• Reduce colonization of gastrointestinal tract; peptic ulcer prophylaxis.
• Avoid gastric overdistention.
• Ensure adequate nutrition.
• Perform daily spontaneous awaking trials and spontaneous breathing trials.
• Use positive end-expiratory pressure of at least 5 cm H2O.
• Minimize transports out of the unit for diagnostic studies.
Hand Hygiene and Related Precautions
The basic tenant of infection control is to ensure that organisms are not transferred from one patient to another. This dictates proper hand hygiene before and after all patient contacts. Gloves should be worn during the patient interaction if there is potential for contact with body secretions. Depending on the infectious condition of the patient, additional precautions such as gown, gloves, and/or a mask may be necessary. Reusable equipment must be cleaned and disinfected appropriately before it is used on another patient.
Care of the Artificial Airway
Orotracheal intubation is preferred over nasotracheal intubation. The cuff on the artificial airway should be inflated to 20 to 30 cm H2O during exhalation to minimize aspiration of secretions and to minimize tracheal injury. However, even at this pressure, microaspiration can occur through the longitudinal folds in the cuff. To minimize pooling of secretions above the cuff, deep pharyngeal suctioning should be performed on a regular basis and before movement of the patient. Use of endotracheal tubes with subglottic suction ports may reduce the risk of VAP, but care is necessary to prevent occlusion of the suction port. Concern has been raised about the potential for tracheal injury due to the suction and the potential for laryngeal injury due to the rigidity of the tube. Endotracheal tubes coated with silver and the use of devices that scrape the inside of the tube to remove secretions are also available. Newer tapered cuff designs and cuff material (ultrathin polyurethane) may reduce microaspiration. The cost-effectiveness, however, of these newer tube designs and devices is yet to be determined.
Care of the Ventilator Circuit
Ventilator circuits do not need to be changed on a routine basis. Not breaking the circuit is important so that the interior of the circuit is not contaminated. An important part of this practice is use of inline suction catheters. Inline catheters become part of the circuit and do not need to be changed routinely. Any condensate that accumulates in the circuit should be removed away from the patient and from the circuit aseptically. The type of humidification, whether active or passive, does not affect VAP rates. If aerosolized medications are delivered, a device that remains in the ventilator circuit should be used (spacer for metered-dose inhaler, mesh nebulizer, or T-connector with a valve for jet nebulizers). Reusable nebulizers should be rinsed with sterile water (or saline) between treatments and allowed to air dry.
Important to VAP prevention is oral hygiene. The goal is to reduce the bacterial load in the mouth and pharynx. This includes suctioning of the oropharynx, teeth brushing, and the use of chlorhexidine wash.
Use noninvasive ventilation (NIV) when appropriate to decrease the risk of VAP. NIV reduces the risk of VAP because intubation is avoided.
Minimize the Duration of Mechanical Ventilation
The shorter the time that a patient remains intubated, the lower the risk of VAP. Thus, daily spontaneous awaking trials and spontaneous breathing trials should be used to identify extubation readiness. Re-intubation is also associated with VAP risk, so efforts should be used to minimize extubation failure such as the use of NIV in patients at risk.
Positive End-Expiratory Pressure
The use of positive end-expiratory pressure (PEEP) has been shown to reduce VAP rate. The mechanism is that the positive tracheal pressure inhibits microaspiration past the cuff on the artificial airway.
Avoid Unnecessary Transport
Transport of ventilated patients out of the ICU has been shown to increase the risk of VAP. Thus, patient transports for diagnostic tests should be minimized, and care should be taken to avoid contamination of the airway during transport.
Mechanically ventilated patients should be positioned with the head elevated to more than 30 degrees unless there is a contraindication to this position. This is to avoid reflux of gastric contents into the oropharynx and its subsequent aspiration. Some investigators, however, believe that prone position or lateral Trendelenburg position may be more effective in removing secretions and preventing aspiration.
Management of the Gastrointestinal Tract
Reduction of the bacterial load of the gastrointestinal tract affects the risk of VAP. Peptic ulcer prophylaxis is recommended. Appropriate nutritional support should be maintained, but gastric overdistention should be avoided to reduce the risk of regurgitation. Selective decontamination of the gastrointestinal tract has been used in Europe, but this approach has not been widely adopted elsewhere.