May the drain be a way in for microbes in surgical infections?

BACKGROUND: Surgical site infection (SSI) is among the most frequent hospital-acquired infections occurring in surgical patients and leads to increased morbidity, mortality, and costs. We aimed to identify risk factors for SSI in patients undergoing surgical procedures, with a particular attention to the use of drains. METHODS: This study includes all patients undergoing abdominal surgical procedures in 2 surgical wards in a teaching hospital in central Italy. Collected data included patient's demographic and clinical characteristics, procedure characteristics, administration of perioperative antibiotic prophylaxis, and microorganism isolated. The outcome of interest was SSI. FINDINGS: A total of 872 abdominal surgery procedures were surveyed during the study period. Drains were placed in 37.0% of cases. SSI rate was 6.4% globally and 13.6% among the patients with drains, versus 2.4% in those without a drain (P < .001). In 72.1% of cases antibiotic prophylaxis was administered. The logistic regression analysis (P < .001) shown insertion of a drain (odds ratio [OR], 5.14; 95% confidence interval [CI], 2.63-10.08), prolonged surgery (OR, 1.98; 95% CI, 1.09-3.59), and American Society of Anesthesiologists score equal to 3 (OR, 6.13; 95% CI, 2.33-16.11) as independent risk factors for SSI, whereas antibiotic prophylaxis was protective (OR, 0.53; 95% CI, 0.29-0.99). CONCLUSION: This study revealed surgical drains as a risk factor for SSI, pointing out the need of a clearer understanding of drain role in the dynamics of SSI occurrence, with the purpose of decreasing infection risk through targeted preventive interventions.