To assess the efficacy of prophylaxis in digestive tract surgery using a predictive model of complication risk

One hundred and ninety-one patients, all candidates for major clean-contaminated surgery, were classified according to the risk of developing postoperative wound infection, using clinical and nutritional factors. A widely validated nutritional assessment model, the Prognostic Nutritional Index (PNI), was used preoperatively to evaluate the risk and probability of post-operative septic complications. Based on the predicted outcome, patients were assigned to either a poor or a good risk group for statistical comparison. A prospective, double-blind, randomized trial was performed to compare the effectiveness of the monocyclic beta-lactam, aztreonam, with gentamicin for short-term perioperative prophylaxis. In the poor risk group (PNI greater than 40), aztreonam prophylaxis significantly reduced postoperative septic complications (p less than 0.05). The use of an objective scoring system to assess the risk of postoperative sepsis is recommended for future studies on antibiotic prophylaxis as it offers a realistic assessment basis.