Risk Factors for Surgical Site Infection Following Elective Abdominal Surgery: A Prospective Observational Study

Abstract

Background: Surgical site infection (SSI) is among the most common and costly healthcare-associated infections, prolonging hospitalisation, increasing morbidity, and consuming substantial healthcare resources. Elective abdominal surgery carries a particular risk owing to the potential for endogenous bacterial contamination. This study was undertaken to determine the incidence of SSI and to identify the independent risk factors associated with its development following elective abdominal operations.

Methods: A prospective observational study was conducted on 300 patients undergoing elective abdominal surgery over an 18-month period. Patient-related, operative, and perioperative variables were recorded prospectively. Surgical wounds were assessed daily during admission and at follow-up on postoperative days 7, 14, and 30 using the Centers for Disease Control and Prevention (CDC) criteria. Risk factors were analysed by univariate testing (chi-square and Student's t-test) followed by multivariate logistic regression; p < 0.05 was considered significant.

Results: SSI developed in 42 of 300 patients (14.0%). On univariate analysis, diabetes mellitus, obesity (BMI ≥ 30 kg/m²), smoking, low serum albumin (< 3.5 g/dL), pre-existing anaemia, prolonged operative time (> 120 min), contaminated/dirty wound class, and prolonged preoperative hospital stay were significantly associated with SSI. On multivariate logistic regression, diabetes mellitus (OR 3.42; 95% CI 1.68–6.95), obesity (OR 2.88; 95% CI 1.41–5.87), operative time > 120 minutes (OR 2.64; 95% CI 1.29–5.40), wound contamination class (OR 3.10; 95% CI 1.52–6.32), and hypoalbuminaemia (OR 2.35; 95% CI 1.14–4.83) remained independent predictors. The most frequently isolated organism was Escherichia coli, followed by Staphylococcus aureus.

Conclusion: SSI following elective abdominal surgery is common and multifactorial. Diabetes, obesity, prolonged operative time, wound contamination, and hypoalbuminaemia are independent, largely modifiable risk factors. Optimisation of glycaemic control, nutritional status, and operative efficiency, together with appropriate antibiotic prophylaxis, may reduce the burden of SSI.