UTILITY OF SELECTIVE DIGESTIVE DECONTAMINATION IN MECHANICALLY VENTILATED PATIENTS

Objective: To assess selective digestive decontamination for preventing nosocomial pneumonia and mortality in mechanically ventilated patients. Design: Prospective, randomized, placebo-controlled, double-blind study. Setting: Respiratory intensive care unit of a 1000-bed teaching hospital. Patients: 80 patients receiving mechanical ventilation for more than 72 hours. Interventions: Patients received selective digestive decontamination using polymyxin E, tobramycin, and amphotericin B through a nasogastric tube and also topically in the oropharynx; control patients received placebo. All patients received intravenous cefotaxime for 4 days or other systemic antibiotics if required. Measurements: Bacteriologic surveillance (three times a week) was done by quantitatively culturing tracheal aspirates, pharyngeal swabs, and gastric juice. The diagnosis of pneumonia was based on quantitative cultures of protected specimen brush samples (greater than or equal to 10(3) CFU/mL [colony forming units/mL]) or bronchoalveolar lavage fluid (greater than or equal to 10(4) CFU/mL) and autopsy findings. Results: Bronchial, oropharyngeal, and gastric colonization by gram-negative bacilli and Candida species was lower in the selective digestive decontamination group compared with the placebo group. Nonsignificant differences were found in the incidence of nosocomial infections (28% compared with 37%; odds ratio, 0.66; 95% Cl, 0.35 to 1.25) and nosocomial pneumonia (18% compared with 24%; odds ratio, 0.7; Cl, 0.33 to 1.46) and in the crude mortality rate (31% compared with 27%; odds ratio, 1.21; Cl, 0.63 to 2.34) when comparing digestive decontamination with placebo, respectively. Conclusions: Selective digestive decontamination in our mechanically ventilated patients significantly decreased the colonization rate of gram-negative bacilli and of Candida species but not of Staphylococcus aureus. It did not decrease the incidence of nosocomial pneumonia, mortality, length of stay, or the duration of mechanical ventilation.