Selective decontamination of the digestive tract as an infection-control measure in intensive care unit patients.

Infection is responsible for a large percentage of morbidity and mortality in intensive care unit (ICU) patients. Conventional infection-control measures are directed at decreasing infection by exogenous sources and have had variable success in significantly reducing nosocomial infection rates. Selective gastrointestinal decontamination with topical nonabsorbable antibiotics attempts to reduce infection by eliminating intestinal mucosal colonization by pathogenic microorganisms. These antibiotics are selectively bactericidal against gram-negative organisms and yeasts, thereby leaving the normal flora (mainly anaerobes) unharmed. In the majority of clinical trials, selective decontamination effectively reduced colonization and infection among ICU patients, with the most significant reductions observed in gram-negative respiratory infections. Resistance to the antimicrobials was not documented in the majority of trials; however, follow-up periods were minimal and may not have been adequate to detect selection of resistant strains. Reductions in infection do not alter mortality; however, patients without significant underlying disease appear to be the subgroup that will most likely benefit.