Selective decontamination of the digestive tract in elective gastrointestinal surgery

Gastrointestinal (GI) surgery and especially colorectal surgery is associated with a high risk of postoperative infections due to contamination by bacteria in the large intestine. These postoperative infectious complications increase hospital stay and costs of treatment. The most common infectious complications after surgery are urinary tract, wound and pulmonary infections. These mainly Gram negative infections generally originate from the patient’s own digestive tract.
The use of oral antibiotics on top of systemic antibiotic treatment, was introduced into intensive care medicine by Chris Stoutenbeek in 1984 as an infection-prophylaxis regimen to reduce or even eradicate aerobic potentially pathogenic microorganisms (PPMs) , from oro-pharynx to rectum, while leaving the normal anaerobic flora, who are responsible for maintaining a sufficient colonisation resistance, largely undisturbed. It was called selective decontamination of the digestive tract (SDD) and consisted of a topical, non-absorbable, antibiotic combination of Polymixin, Tobramycin and Amphotericin B, which was taken orally, four times daily. A significant decrease in bloodstream- and respiratory infections and mortality was found on the ICU population.
The aim of this thesis was to analyse the effect of peri-operative SDD combined with systemic perioperative antibiotics in elective gastrointestinal surgery, on postoperative infectious complications and anastomotic leakage. We therefore performed a retrospective analysis, a randomised clinical trial, a cost-effectiveness study, a systematic review and meta-analysis of the literature to determine the effect of SDD in GI surgery. Furthermore, we hope that this thesis gives an overview of the clinical applicability of SDD in gastro-intestinal surgery.