Selective decontamination of the digestive tract: effect of cessation of routine application at an ICU

Background: Selective decontamination of the digestive tract (SDD) with non-absorbable antibiotics was extensively used at intensive care units (ICU) in Europe to prevent nosocomial infections in critically ill patients. After three recent meta-analyses in which it was demonstrated that SDD did not influence hospital stay and mortality in these patients several ICU's decided to stop the routine use of SDD. Objective: To examine the effects of the cessation of SDD on nosocomial infections, mortality and hospital stay at an ICU in post-operative patients.Design: Retro-and prospective follow-up.Patients: Post-operative patients with mechanical ventilation (MV) for ≥5 days at an ICU were included. The retrospective group (SDD group) comprised of 138 patients (mean age 66, range 10–91; 78% male) and the prospective group (non-SDD group) of 142 patients (mean age 67, range 18–85; 65% male). The SDD regime consisted of colistin, tobramycin and amphotericin B. Cessation of the SDD was accompanied by a shortening of the routine intravenous cefuroxime prophylaxis.Results: There was a nonsignificant increase from an average 21 to 23 days ICU stay in the non-SDD group when compared with the SDD group (p>0.05). Of the 280 patients 97 (35%) died on the ICU. The risk of death was lower in the non-SDD group (adjusted hazard ratio 0.7 with 95% CI 0.5–1.1). There was a trend towards an increase in infections as a cause of death in the non-SDD group (38% of the ceased patients versus 20% in the SDD group) (p>0.05). The incidence of respiratory tract infection (per 1000 person days) was 80 (95% CI 48–113) in the non-SDD group versus 19 (95% CI 8–22) in the SDD group (adjusted hazard ratio 4.5 (95% CI 2.9–7.1)). Conclusion: The cessation of the routine application of SDD in post-operative patients mechanically ventilated for 5 days or more did nod adversely affect survival nor increased length of stay at the ICU. There may have been a shift to infections as a cause of death after cessation of SDD.