Using antiseptics to orally decontaminate mechanically ventilated adults reduces the risk of ventilator-associated pneumonia (VAP), although mortality, duration of mechanical ventilation, and length of intensive care unit stay are unaffected, report a Singaporean and Canadian team.

The incidence of VAP among mechanically ventilated patients ranges from 9% to 28%, with a crude mortality rate for affected patients potentially over 50%. Furthermore, aspiration of bacteria from the upper digestive tract is a major source of infection.

Determining the impact of oral decontamination on the incidence of CAP and mortality in mechanically ventilated patients, the team, led by Ee Yuee Chan, from Tan Tock Seng Hospital in Singapore, conducted a search of databases such as MedLine, Embase, and the Cochrane Library, as well as trial registers, reference lists, and conference proceedings for relevant studies.

In all, 11 trials, involving 3,242 patients were included in the study. They were all randomized controlled trials that compared the effects of daily oral application of antibiotics or antiseptics, without prophylaxis, in mechanically ventilated adults.

Oral application of antibiotics, which was assessed in four trials involving 1,098 patients, did not have a significant impact on the incidence of VAP, at a relative risk of 0.69. However, the seven trials, involving 2,144 patients, that assessed oral application of antiseptics revealed a significant reduction in the incidence of VAP, at a relative risk of 0.59.

Pooling the results of the 11 trials, the team found that VAP rates were lower among patients receiving either kind of oral decontamination than other patients, at a relative risk of 0.61. In contrast, there was no effect on mortality from either antibiotics, at a relative risk of 0.94, or antiseptics, which yielded a relative risk of 0.96. There was also no effect of oral decontamination on the duration of mechanical ventilation or the length of stay in the intensive care unit.

The team concludes in the British Medical Journal (currently in press): “This systematic review suggests that, in mechanically ventilated patients, antiseptic oral decontamination prophylaxis reduces the incidence of VAP. More evidence is needed before firm conclusions can be made on the effect of antibiotic oral decontamination.”