Bacterial resistance and overgrowth due to selective decontamination of the digestive tract

Infection of the lower airways is a major problem in ventilated patients an d contributes substantially to morbidity and mortality in the intensive car e unit. The selective decontamination of the digestive tract and its effect on the reduction of the gram-negative colonisation rate in patients has be en studied widely. However, the findings are inconsistent. Most studies des cribe an increase in resistant gramnegative bacterial strains and/or an inc rease in the occurrence of gram-positive strains following selective decont amination of the digestive tract. In light of the unresolved questions conc erning the efficacy of selective decontamination of the digestive tract, it would seem that the resultant effect of this treatment on the bacterial fl ora should be an important consideration when assessing the value of such t reatment. To date, none of the studies available for examination have been designed to adequately assess the effect of selective decontamination of th e digestive tract on the bacterial flora.