Ventilator-associated pneumonia: Does toothbrushing with chlorhexidine reduce risk?


It has been reported that between 6-52% of ventilated patients develop ventilator-associated pneumonia with an attributable mortality of 10%. The oral cavity is a potential reservoir for infection and studies and reviews have demonstrated benefit from oral hygiene measures for ventilated patients.

The aim of this review was to assess the effect of toothbrushing and chlorhexidine on the incidence of ventilator-associated pneumonia in patients on mechanical ventilation


Searches were conducted in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Web of Science and Scopus databases with no language restrictions. Randomised controlled trials (RCTs) comparing chlorhexidine and toothbrushing verses chlorhexidine alone were considered. Outcome measures included incidence of ventilator-associated pneumonia (VAP), ICU mortality, length of stay and duration of mechanical ventilation. Two reviewers reviewed the titles and abstract, selected studies and extracted data. Risk of bias was assessed using the Cochrane domains-based tool. Random effects meta-analyses were conducted, and relative risks (RR) and weighted mean differences (WMDs) 95% confidence intervals (CIs) calculated.


  • 7 RCTs published between 2009 and 2020 involving a total of 1424 patients were included.
  • 6 RCTS (1332 patients) reported on VAP with 69 cases in the chlorhexidine (CHX) and toothbrushing group compared with 104 cases in the CHX group.
  • Meta-analysis showed a significant reduction in cases of VAP, duration of mechanical ventilation and length of stay in the CHX and toothbrushing group compared with CHX alone (see table).
Outcome No of studies  
VAP 6 RR = 0.67 (95%CI: 0.50 to 0.88)
ICU mortality 5 RR = 0.88 (95%CI: 0.73 to 1.06)
Duration of mechanical ventilation 4 WMD = -1.38 days (95%CI: -2.43 to −0.33)
Length of stay 4 WMD = -1.47 days (95%CI: -2.74 to −0.20)


The authors concluded: –

Our study suggests that using toothbrushing in conjunction with CHX can be a highly beneficial modality for reducing the risk of VAP in patients on MV. This intervention also positively affects other clinical parameters, such as the period of stay in the ICU and the total duration of MV. Further large-scale, well-designed clinical trials will help in establishing the benefits of CHX+T and developing a standardized oral care protocol for reducing the risk of VAP.


The authors have searched 4 major databases with no language restriction. While two reviewers selected, extracted, and assessed quality of the studies it is not fully clarified whether this was carried out independently. A recent Cochrane review update (Dental Elf – 11th Jan 2021) considered a range of oral health measures for patients on mechanical ventilation in intensive care. This review compares chlorhexidine and toothbrushing verses chlorhexidine alone and only 3 of the studies are common to both reviews.  The Cochrane review found,

Chlorhexidine mouthwash or gel, as part of oral health care (OHC), probably reduces the incidence of developing ventilator-associated pneumonia (VAP) in critically ill patients from 26% to about 18%, when compared to placebo or usual care.

Interestingly Cochrane did not find difference in mortality, duration of mechanical ventilation or duration of stay in the intensive care unit in contrast this more specific review did show a difference in both duration of ventilation and length of stay in ICU. Cochrane assessed the available evidence as being of very low quality and none of the RCTs included in the new review are at low risk of bias. Given the serious risk that VAP poses additional high quality well-reported studies are needed to clarify the most effective oral care regimen for patients on mechanical ventilation and whether there is a definitive effect on duration of ventilation and length of stay.


Primary Paper

Sozkes S, Sozkes S. Use of toothbrushing in conjunction with chlorhexidine for preventing ventilator-associated pneumonia: A random-effect meta-analysis of randomized controlled trials. Int J Dent Hyg. 2021 Oct 23. doi: 10.1111/idh.12560. Epub ahead of print. PMID: 34687588.

Other references

Dental Elf – 11th Jan 2021

Oral hygiene for critically ill patients

Dental Elf – Ventilator associated pneumonia blogs







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