Sharon Dickinson MSN, RN, CNS BC
Clinical Nurse Specialist
University of Michigan
Ann Arbor, Michigan, USA

Christy Ann Zalewski, MPH
Infection Control Practitioner
University of Michigan
Ann Arbor, Michigan, USA

The role of oral hygiene in maintaining the health and well-being of patients in the intensive care unit (ICU) is indisputable.(1) Oral care is a simple and effective strategy to reduce ventilator-associated pneumonia (VAP) in patients requiring mechanical ventilation. Colonization of the aerodigestive tract and aspiration of contaminated secretions into the lower airway are the two primary pathogenic processes of endemic VAP.(2)

Dental plaque can be a major reservoir of infection by respiratory pathogens in ICU patients.(3) Pharmacological plaque control with chlorhexidine oral rinse is effective and also decreases oropharyngeal colonization by aerobic pathogens in ventilated patients.(4)

Dentists have used chlorhexidine since 1959 for reducing dental plaque, for treating gingivitis, and for use in patients who cannot brush their own teeth. Mechanical tooth cleaning, such as tooth brushing and vigorous suctioning, are also important approaches to reduce oral bacteria and thereby reduce bacterial colonization of the aerodigestive tract.

Oral care practices in ICUs are not consistent or standardized. A recent survey of oral care practices in 59 European ICUs documented that oral care practices were carried out once daily in 20%, twice daily in 31%, and three times daily in 37% of patients. Oral care consisted primarily of mouth washes (55%) performed with chlorhexidine (61%). In contrast, only 41% used manual toothbrushes for oral care, and electric toothbrushes were never used.(5) A survey of oral care practices in U.S. ICUs had similar findings.(6) The frequency of oral hygiene for intubated patients is controversial. 

A recent Centers for Disease Control and Prevention (CDC) survey of 1,200 nurses documented that half had an oral care protocol in their hospital for the prevention of VAP.(7) Nurses in hospitals with a protocol reported improved compliance with hand washing and maintenance of bed elevation. They also were more likely to provide oral care regularly, and were more familiar with rates of VAP and the organisms involved than those working in hospitals without such protocols.

Consistent efforts to improve oral care in the ICU are critically important.(8) Reinforcing proper oral care in educational programs, allowing sufficient time to provide oral care, and developing standardized protocols for oral care in intubated patients are all necessary components (see Tables 1 and 2). Implementing an evidence-based practice education program on the role of oral care in VAP prevention was associated with improved and more frequent oral care and a significant reduction in the incidence of VAP at the University of Michigan Hospitals and Health Centers (see Figure 1).(9)

Other recent studies have confirmed the University of Michigan’s experience: topical chlorhexidine for the prevention of VAP is effective.Chlorhexidine (CHX) gluconate 0.12% oral rinse was first demonstrated to reduce the incidence of total nosocomial respiratory infections by 69% in patients undergoing cardiac surgery (n=353). A mortality reduction in the CHX-treated group also was noted.(10) Another single-center prospective cohort study documented that CHX was effective in reducing the incidence and associated mortality of VAP in surgical ICU patients.(11) Another study compared CHX to Listerine® (McNeil-PPC, Inc., Morris Plains, NJ) in 561 cardiac surgery patients and demonstrated a 71% reduction in VAP in patients intubated for >24 hours.(12)

A prospective, randomized, double-blind, placebo-controlled multicenter trial (n=385) in patients requiring mechanical ventilation for 48 hours or more randomized patients to placebo, CHX 2% every six hours, or CHX 2%-colistin 2% every six hours. Topical oral decontamination with CHX or CHX and colistin reduced the incidence of VAP.(13) Decontamination of the nasopharynx and oropharynx with CHX significantly reduced nosocomial infections after cardiac surgery in a randomized trial that concluded that for the prevention of one nosocomial infection, 16 patients needed to be treated with CHX.(14)

Two recent meta-analyses regarding the efficacy of topical chlorhexidine for prevention of VAP concluded that oral decontamination of mechanically ventilated adults using antiseptics is associated with a lower risk of VAP (relative risk and 95% confidence interval 0.74 [0.56-0.96]15 and 0.61 [0.45-0.82],(16) respectively). Limitations clearly have been delineated in these studies, including different patient populations studied (cardiac, surgical and medical), duration of mechanical ventilation, concentration of CHX used, timing and method for CHX application, and lack of standardized definition of VAP.(17)

A more recent randomized controlled trial, presented as an abstract during the Society of Critical Care Medicine’s 36^th Critical Care Congress, assigned intubated ICU patients to one of four treatments: usual care, tooth brushing three times daily, CHX twice daily, or tooth brushing and CHX combined. CHX significantly reduced VAP (24.4% vs. 52.4%, p=0.0093) compared with tooth brushing alone.(18)

The CDC’s Guideline for Preventing Healthcare-Associated Pneumonia recommends CHX use only during the perioperative period for adult patients undergoing cardiac surgery; routine use in other critically ill populations is not recommended. (19) The Evidence-Based Clinical Practice Guideline for the Prevention of Ventilator-Associated Pneumonia by the Canadian Critical Care Trials Group and the Canadian Critical Care Society(20) did not provide recommendations regarding oral care and topical CHX for prevention of VAP. Given the results of these recent studies, updates to these two documents and the American Association of Critical- Care Nurses (AACN) guidelines may be necessary.

The method of application of CHX for VAP prevention is also critical. Complete cleansing of the mouth and oropharynx must be done before application of CHX. Avoiding brushing or the use of mouthwashes for at least two hours after the CHX application is advisable. CHX creates a film that adheres and remains on the teeth to provide antibacterial activity. Prolonged use can stain both natural and artificial teeth. Discoloration can be removed during the next dental cleaning and does not usually occur unless use exceeds several weeks. Caregivers should explain the reason for CHX to patients and families.

Additional studies are in progress to investigate the potential efficacy of CHX spray and gel for VAP reduction. Further studies are needed to discern the optimal methods (foam swabs, toothbrushes and mechanical toothbrushes) to reduce bacterial colonization of the oropharynx and remove dental plaque in ICU patients at risk for nosocomial infection.

The Bottom Line
Prior to 2005, the University of Michigan Hospitals and Health Centers made several attempts to decrease VAP (elevating head of bed, gastrointestinal prophylaxis, and extensive staff education) without success. Although the AACN guidelines(21) did not support the use of oral CHX, in 2005 the University of Michigan instituted a standardized protocol for oral care and topical CHX in all intubated patients (see Table 2). The initial education involved presentation of the protocol to all nursing staff, followed by reinforcement through nursing newsletters and during break sessions. These measures resulted in a significant reduction in the VAP rate. The rates periodically are sent to staff to highlight the impact of the protocol. To maintain and further reduce the VAP rate, the University of Michigan Hospitals and Medical Centers standardized the protocol so that it no longer requires a physician order, thus promoting optimal compliance. The provision of oral hygiene is necessary in all critically ill patients. Every hospital should implement a VAP prevention protocol that includes an oral care component.



Table 1.The BRUSHED Assessment Model for standardized oral assessment.
B BLEEDING?
   (Gums, mucosa, coagulation, status?)
R REDNESS?
   (Gum margins, tongue? Antibiotic stomatitis?)
U ULCERATION?
   (Size, shape, herpetic? Infected?)
S SALIVA?
   (Xerostomia, hypersalivation, characteristics?)
H HALITOSIS?
    (Character? Acidotic? Infected?)
E EXTERNAL FACTORS?
   (Angular chelitis? Endotracheal tapes?)
D DEBRIS?
   (Visible plaque? Foreign particles?)

Hayes J, Jones C. A collaborative approach to oral care during
critical illness. Dent Health (London). 1995;34:6.

Table 2. University of Michigan Surgical ICU Oral Care Protocol
Preparation
• Gather oral care supplies.
• Wash hands and don gloves.
Technique
• Suction oropharyngeal and retropharyngeal secretions.
• Using a soft toothbrush and toothpaste, brush the patient’s
teeth, gums and tongue.
• Rinse mouth and suction.
• Pour 15 mL chlorhexidine gluconate into medication cup.
• Rigorously apply all 15 mL of solution to the buccal,
pharyngeal, gingival, tongue, and tooth surfaces for 30
seconds.
• Suction excess.
• With a gloved finger, apply mouth moisturizer.
• Remove gloves and wash hands.

References