John: Cochrane has several systematic reviews about the management of patients in intensive care units, covering a wide range of interventions, and the update of one of these in October 2016 brought together the latest evidence on the effects of oral hygiene care. Helen Worthington, one of the authors on the review and Co-ordinating Editor of the Cochrane Oral Health Group at the University of Manchester in the UK tells us more.

Helen: Many patients in intensive care units in hospital need mechanical ventilation because their ability to breathe unassisted is impaired by trauma, a medical condition or recent surgery. One of the complications that may develop is ventilator-associated pneumonia, which is generally defined as a pneumonia developing in a patient who has received mechanical ventilation for at least 48 hours. The incidence of ventilator associated pneumonia in these patients has been found to be as high as 52% in some studies.
We also know that oral health deteriorates following admission to a critical care unit. Dental plaque may accumulate more quickly in these patients because of the increased likelihood of dry mouth, and the presence of the ventilation tube which makes oral care more difficult. These critically ill patients are dependent on hospital staff to meet their needs for nutrition and hygiene, including oral hygiene, and it’s important to know how best to deliver this.
With that in mind, our review evaluates all oral hygiene care interventions, used in patients on ventilators in intensive care units, apart from antibiotics, to determine the effects on the development of ventilator associated pneumonia. Secondary outcomes included mortality and any reported adverse events of the interventions.
We included 38 trials, with over 6,000 patients in total in the review. The two main comparisons were oral hygiene using a chlorhexidine mouth wash or gel compared to placebo or usual care, and oral hygiene with toothbrushing compared to oral hygiene without it.
There was high quality evidence, based on 18 trials, that chlorhexidine rinse or gel as part of oral hygiene care reduced the risk of ventilator associated pneumonia from about 25% to 19%. There was no evidence of a difference in the proportion of deaths between using chlorhexidine or not using it and, in the two trials that were the only ones to present information on adverse effects, these were reported to be mild with similar numbers in both groups.
The evidence on toothbrushing (with or without antiseptics) is weaker. We found that the effect on ventilator associated pneumonia is uncertain, based on low quality evidence from 5 trials, and there was no evidence of a difference in death with and without toothbrushing.
In summary, oral hygiene care including chlorhexidine mouthwash or gel reduces the risk of developing ventilator-associated pneumonia in critically ill patients. However, we found no evidence of a difference in mortality. There is no evidence that oral hygiene care including toothbrushing is different from oral hygiene care without it for preventing ventilator–associated pneumonia, but we’d like to see further research into this. There is also insufficient evidence to determine whether any of the interventions evaluated in the studies are associated with adverse effects.

John: Thanks Helen. If you would like to find out more about these two main comparisons from the Cochrane Review, and the other interventions studied in the 38 trials, just go to Cochrane Library dot com and search ‘mechanical ventilation and oral health’.