Risk factors of surgical wound infection in patients undergoing herniorrhaphy

Abstract

Objective: To study the causes of surgical wound infection in patients being operated on for abdominal hernias.

Design: Prospective cohort study.

Setting: A tertiary hospital, Spain.

Subjects: 497 subjects undergoing herniorrhaphy.

Main outcome measures: Incidence of surgical wound infection during hospital stay and with an extended follow-up to one month after hospital discharge.

Results: During follow-up, 40 patients (8%) developed wound infections. The risk was unrelated to ASA grade, sex, age, severity of underlying disease, or number of diagnoses. Logistic regression analysis included six variables in the model. The most important two were duration of intervention (OR for each hour = 2.1, 95% confidence interval (CI) = 1.1 to 4.0) and the infection risk of the surgeon (taking the medium-risk level as reference, OR for low risk = 0.16, 95% CI = 0.03 to 0.81; OR for high risk = 1.83, 95% CI = 0.84 to 3.96). Logistic regression also included cancer, morbid obesity, and serum creatinine and HDL-cholesterol concentrations in the final model. The deviance (as regarding a saturated model including the six variables) of a model including only duration of intervention and surgeon was lower than that of a model with the remaining four factors.

Conclusions: The risk of infection is governed mainly by factors associated with the operation.