A comparison of Listerine® and sodium bicarbonate oral cleansing solutions on dental plaque colonisation and incidence of ventilator associated pneumonia in mechanically ventilated patients: A randomised control trial

Effective oral hygiene has been proposed as a key factor in the reduction of dental plaque colonisation and subsequent development of ventilator associated pneumonia (VAP). Listerine® oral rinse, while used extensively in dental practice has rarely been tested in mechanically ventilated patients. Sodium bicarbonate as an oral rinse has been more commonly utilised in oral hygiene regimens in intensive care patients. To test the efficacies of the essential oil mouth rinse, Listerine® (Pfizer) and sodium bicarbonate in the reduction of dental plaque colonisation with respiratory pathogens and the subsequent development of VAP. The study design was a prospective, single blind randomised comparative study of adult patients mechanically ventilated for at least 4 days. Patients were randomised to Listerine® (Pfizer) oral rinse twice daily, sodium bicarbonate oral rinse 2/24 or sterile water 2/24 (control group). All groups received tooth brushing 3 times a day. Dental plaque colonisation (primary outcome) and incidence of ventilator associated pneumonia (secondary outcome) were studied. Three hundred and ninety-eight patients were randomised to either the Listerine group (127), sodium bicarbonate group (133) or the control group (138). Baseline characteristics were similar for all groups. There were no significant differences between the control and study groups in colonisation of dental plaque at Day 4 (p=0.243). Ventilator associated pneumonia was diagnosed in 18 patients. The incidence was, Listerine® group 4.7%, sodium bicarbonate group 4.5% and control 4.3% [OR, 0.99; 95% CI, 0.31 to 3.16; p=0.92]. Compared to the control group, Listerine® or sodium bicarbonate oral rinses were not more effective in the reduction of colonisation of dental plaque or the incidence of VAP. Given the low incidence of VAP, the common factor of a small, soft toothbrush as part of an oral hygiene regimen suggests possible benefit in mechanically ventilated patients.