Pileggi et al analyzed 28 studies and concluded that decontaminating the GI/respiratory tract with antiseptics reduced ventilator-associated pneumonia by 27%; decontamination with antibiotics reduced VAP by 36%. Antibiotic decontamination also reduced ICU infections in general, by 29%. Critical Care 2011;15:R155. FREE FULL TEXT

Also see last month's "Oral / gastric antibiotic decontamination reduced bacteremias in ICU."