Eleven RCTs (n=3,242) were included.
Most of the studies were double-blind, used a computer-generated sequence for the randomisation, and used pharmacy-controlled allocation. All of the studies had explicit inclusion and exclusion criteria. All but one unclear study showed similar baselines of the treatment arms. The majority of the studies described the patients excluded after randomisation.
Oral application of antibiotics (4 trials) did not significantly reduce the incidence of VAP (RR 0.69, 95% CI: 0.41, 1.18) or mortality (RR 0.94, 95% CI: 0.73, 1.21).
Oral application of antiseptics (7 trials) significantly reduced the incidence of VAP (RR 0.56, 95% CI: 0.39, 0.81), but showed no effect on mortality (RR 0.96, 95% CI: 0.69, 1.33). There was evidence of statistical heterogeneity.
The pooled results of antibiotic and antiseptic interventions (11 trials) showed a significant effect on the incidence of VAP in favour of oral decontamination (RR 0.61, 95% CI: 0.45, 0.82), but still no significant effect on mortality.
There were no differences in terms of the duration of mechanical ventilation or the length of stay in intensive care.
The funnel plot showed some asymmetry, but both statistical tests were negative (p=0.111, p=0.175).