Selective digestive decontamination in patients in intensive care. The Dutch Working Group on Antibiotic Policy

Selective digestive decontamination (SDD) is the most extensively studied method for the prevention of infection in patients in intensive care units (ICUs). Despite 27 prospective randomized studies and six meta-analyses, routine use of SDD is still controversial. In this review, we summarize the available scientific information on effectiveness of SDD in ICU patients. The effects of SDD have been studied in different combinations of the concept, using different antibiotics. Comparison of the individual studies, therefore, is difficult. In most studies, SDD resulted in significant reductions in the number of diagnoses of ventilator-associated pneumonia. However, incidences of ventilator-associated pneumonia in control groups ranged from 5% to 85%. Moreover, these reductions in incidences of ventilator-associated pneumonia in individual studies were not associated with improved patient survival, reductions of duration of ventilation or ICU stay, or reductions in antibiotic use. The numbers of patients studied are too small to determine effects on patient survival. Although two meta-analyses suggested a 20% mortality reduction when using the full concept of SDD (topical and systemic prophylaxis) these results should be interpreted with caution. Formal cost-benefit analyses of SDD have not been performed. SDD is associated with the selection of microorganisms that are intrinsically resistant to the antibiotics used. However, the studies are too small and too short to investigate whether SDD will lead to development of antibiotic resistance. As long as the benefits of SDD (better patient survival, reduction in antibiotic use or improved cost-effectiveness) have not been firmly established, the routine use of SDD for mechanically ventilated patients is not advised.