Infection surveillance and selective decontamination of the digestive tract (SDD) in critically ill patients — results of a controlled study

Abstract
Summary All ICU patients were continuously monitored for infections according to a standard protocol by the physician in charge and an infection control nurse during the first quarter of five consecutive years (1980–1984). The number of patients surveyed was 1,009. The average age was 45.5 years and the average period of stay about four days. 733 patients (72.6%) were intubated and artificially ventilated for three days. A fatal outcome resulted in 13.2% of all patients. 1,129 nosocomial infections were registered in 331 patients, which means an infection rate of 32.8%. The most frequent nosocomial infections were those of the respiratory tract (24.3%). Wound infections developed in 16.6%. The urinary tract was affected in 8.8%. Nosocomial septicaemias were observed in 8.7%. Catheter-associated infections were found in 6.7% of the patients. A fatal outcome resulted in 26% of the patients with nosocomial infections and in 6.9% of the non-infected patients, respectively. There was no significant reduction in nosocomial infections over the five-year period in our ICU. Therefore, a study was designed to evaluate the concept of selective decontamination of the digestive tract (SDD) in critically ill patients in our two surgical/traumatological ICUs. A prospective, consecutive, placebo-controlled study in two ICUs was carried out during four six-month periods. 200 patients who were intubated for at least three days, required intensive care for a minimum of five days, and belonged to either class III or IV according to the “Therapeutic Intervention Scoring System” were included in the study. They received either placebo or a prophylaxis regimen, consisting of polymyxin E, tobramycin and amphotericin B. The rates of nosocomial bronchopulmonary infections (ICU I and II) and urinary tract infections (ICU II) were significantly reduced. There was no significant reduction in wound infection, septicaemia and mortality rates. Selective flora suppression is effective in reducing infection rates in critically ill patients without development of resistant strains.