Oral hygiene care for critically ill patients to prevent ventilator-associated pneumonia

Review question

To assess the effects of oral hygiene care on the incidence of ventilator-associated pneumonia (VAP) in critically ill patients receiving mechanical ventilation in intensive care units (ICUs) in hospitals (excluding the use of antibiotics). The aim was to summarise all the available appropriate research in order to facilitate the provision of evidence-based care for these vulnerable patients.

Trials were grouped into four main comparisons.

1. Chlorhexidine antiseptic mouthrinse or gel compared to placebo (treatment without the active ingredient chlorhexidine) or usual care, (with or without toothbrushing).
2. Toothbrushing compared with no toothbrushing, (with or without chlorhexidine).
3. Powered compared with manual toothbrushing.
4. Oral care with other solutions.

Background

Critically ill people, who may be unconscious or sedated while they are treated in intensive care units often need to have machines to help them breathe (ventilators). The use of these machines for more than 48 hours may result in VAP. VAP is a potentially serious complication in these patients who are already critically ill.

Keeping the teeth and the mouth clean, preventing the build-up of plaque on the teeth, or secretions in the mouth may help reduce the risk of developing VAP. Oral hygiene care, using a mouthrinse, gel, toothbrush, or combination, together with aspiration of secretions may reduce the risk of VAP in these patients.

Study characteristics

This review of existing studies was carried out by the Cochrane Oral Health Group and the evidence is current up to 14 January 2013.

Thirty-five separate research studies were included but only a minority (14%) of the studies were well conducted and described.

All of the studies took place in intensive care units in hospitals. In total there were 5374 participants randomly allocated to treatment. Participants were critically ill and required assistance from nursing staff for their oral hygiene care. In three of the included studies participants were children and in the remaining studies only adults participated. Participants had been hospitalised as medical, surgical or trauma patients. In 13 studies it was not clear which of these three categories the participants belonged to.

Key results

Effective oral hygiene care is important for ventilated patients in intensive care. We found evidence that chlorhexidine either as a mouthrinse or a gel reduces the odds of VAP in adults by about 40%. So for example for every 15 people on ventilators in intensive care, the use of oral hygiene care including chlorhexidine will prevent one person developing VAP. However, we found no evidence that chlorhexidine makes a difference to the numbers of patients who die in ICU, to the number of days of mechanical ventilation or the number of days in ICU.

The three studies of children (aged birth to 15 years) showed no evidence of a difference in VAP between the use of chlorhexidine mouthrinse or gel and placebo in children.

Four studies showed no evidence of a difference between toothbrushing (with or without chlorhexidine) and oral care without toothbrushing (with or without chlorhexidine) in the risk of developing VAP. Two studies showed some evidence of a reduction in VAP with povidone iodine antiseptic mouthrinse.

There was not enough research information available to provide evidence of the effects of other mouth care rinses such as water, saline or triclosan.

Only two of the included studies reported any adverse effects of the interventions (mild oral irritation (one study) and unpleasant taste (both chlorhexidine and placebo)), four studies reported that there were no adverse effects and the remaining studies do not mention adverse effects in the reports.

Quality of the evidence

The evidence presented is of moderate quality. Only 14% of the studies were well conducted and described.

Authors' conclusions: 

Effective OHC is important for ventilated patients in intensive care. OHC that includes either chlorhexidine mouthwash or gel is associated with a 40% reduction in the odds of developing ventilator-associated pneumonia in critically ill adults. However, there is no evidence of a difference in the outcomes of mortality, duration of mechanical ventilation or duration of ICU stay. There is no evidence that OHC including both CHX and toothbrushing is different from OHC with CHX alone, and some weak evidence to suggest that povidone iodine mouthrinse is more effective than saline in reducing VAP. There is insufficient evidence to determine whether powered toothbrushing or other oral care solutions are effective in reducing VAP.

Read the full abstract...
Background: 

Ventilator-associated pneumonia (VAP) is defined as pneumonia developing in persons who have received mechanical ventilation for at least 48 hours. VAP is a potentially serious complication in these patients who are already critically ill. Oral hygiene care (OHC), using either a mouthrinse, gel, toothbrush, or combination, together with aspiration of secretions may reduce the risk of VAP in these patients.

Objectives: 

To assess the effects of OHC on the incidence of VAP in critically ill patients receiving mechanical ventilation in intensive care units (ICUs) in hospitals.

Search strategy: 

We searched the Cochrane Oral Health Group's Trials Register (to 14 January 2013), CENTRAL (The Cochrane Library 2012, Issue 12), MEDLINE (OVID) (1946 to 14 January 2013), EMBASE (OVID) (1980 to 14 January 2013), LILACS (BIREME) (1982 to 14 January 2013), CINAHL (EBSCO) (1980 to 14 January 2013), Chinese Biomedical Literature Database (1978 to 14 January 2013), China National Knowledge Infrastructure (1994 to 14 January 2013), Wan Fang Database (January 1984 to 14 January 2013), OpenGrey and ClinicalTrials.gov (to 14 January 2013). There were no restrictions regarding language or date of publication.

Selection criteria: 

We included randomised controlled trials (RCTs) evaluating the effects of OHC (mouthrinse, swab, toothbrush or combination) in critically ill patients receiving mechanical ventilation.

Data collection and analysis: 

Two review authors independently assessed all search results, extracted data and undertook risk of bias. We contacted study authors for additional information. Trials with similar interventions and outcomes were pooled reporting odds ratios (OR) for dichotomous outcomes and mean differences (MD) for continuous outcomes using random-effects models unless there were fewer than four studies.

Main results: 

Thirty-five RCTs (5374 participants) were included. Five trials (14%) were assessed at low risk of bias, 17 studies (49%) were at high risk of bias, and 13 studies (37%) were assessed at unclear risk of bias in at least one domain. There were four main comparisons: chlorhexidine (CHX mouthrinse or gel) versus placebo/usual care, toothbrushing versus no toothbrushing, powered versus manual toothbrushing and comparisons of oral care solutions.

There is moderate quality evidence from 17 RCTs (2402 participants, two at high, 11 at unclear and four at low risk of bias) that CHX mouthrinse or gel, as part of OHC, compared to placebo or usual care is associated with a reduction in VAP (OR 0.60, 95% confidence intervals (CI) 0.47 to 0.77, P < 0.001, I2 = 21%). This is equivalent to a number needed to treat (NNT) of 15 (95% CI 10 to 34) indicating that for every 15 ventilated patients in intensive care receiving OHC including chlorhexidine, one outcome of VAP will be prevented. There is no evidence of a difference between CHX and placebo/usual care in the outcomes of mortality (OR 1.10, 95% CI 0.87 to 1.38, P = 0.44, I2 = 2%, 15 RCTs, moderate quality evidence), duration of mechanical ventilation (MD 0.09, 95% CI -0.84 to 1.01 days, P = 0.85, I2 = 24%, six RCTs, moderate quality evidence), or duration of ICU stay (MD 0.21, 95% CI -1.48 to 1.89 days, P = 0.81, I2 = 9%, six RCTs, moderate quality evidence). There was insufficient evidence to determine whether there is a difference between CHX and placebo/usual care in the outcomes of duration of use of systemic antibiotics, oral health indices, microbiological cultures, caregivers preferences or cost. Only three studies reported any adverse effects, and these were mild with similar frequency in CHX and control groups.

From three trials of children aged from 0 to 15 years (342 participants, moderate quality evidence) there is no evidence of a difference between OHC with CHX and placebo for the outcomes of VAP (OR 1.07, 95% CI 0.65 to 1.77, P = 0.79, I2 = 0%), or mortality (OR 0.73, 95% CI 0.41 to 1.30, P = 0.28, I2 = 0%), and insufficient evidence to determine the effect on the outcomes of duration of ventilation, duration of ICU stay, use of systemic antibiotics, plaque index, microbiological cultures or adverse effects, in children.

Based on four RCTs (828 participants, low quality evidence) there is no evidence of a difference between OHC including toothbrushing (± CHX) compared to OHC without toothbrushing (± CHX) for the outcome of VAP (OR 0.69, 95% CI 0.36 to 1.29, P = 0.24 , I2 = 64%) and no evidence of a difference for mortality (OR 0.85, 95% CI 0.62 to 1.16, P = 0.31, I2 = 0%, four RCTs, moderate quality evidence). There is insufficient evidence to determine whether there is a difference due to toothbrushing for the outcomes of duration of mechanical ventilation, duration of ICU stay, use of systemic antibiotics, oral health indices, microbiological cultures, adverse effects, caregivers preferences or cost.

Only one trial compared use of a powered toothbrush with a manual toothbrush providing insufficient evidence to determine the effect on any of the outcomes of this review.

A range of other oral care solutions were compared. There is some weak evidence that povidone iodine mouthrinse is more effective than saline in reducing VAP (OR 0.35, 95% CI 0.19 to 0.65, P = 0.0009, I2 = 53%) (two studies, 206 participants, high risk of bias). Due to the variation in comparisons and outcomes among the trials in this group there is insufficient evidence concerning the effects of other oral care solutions on the outcomes of this review.