Risk factors for surgical-wound infection in general surgery: a prospective study

To quantify surgical-infection rate, to assess adherence with the antibiotic prophylaxis protocol, and to identify independent factors associated with surgical-wound infection (SWI).

We carried out a prospective study of a cohort of 2,237 general surgery patients with postsurgery stays of more than 48 hours. Odds ratios (OR) were estimated using unconditional multiple logistic regression.

A 1,300-bed, university-affiliated, tertiary-care hospital in Madrid, Spain.

254 patients developed SWI. The rate of adherence to the antibiotic prophylaxis protocol was 63.5%. Eight factors were independently associated with risk of SWI: age (OR = 1.2 for every 10 years of age); wound classification (clean-contaminated, OR = 6.4; contaminated, OR = 3.7; dirty or infected, OR = 9.3); antimicrobial prophylaxis (OR = 0.5); stay prior to surgery (OR = 1.1 for every 3 days); duration of operation (OR = 1.5 for every 60 minutes); malignant neoplasm (OR = 1.7); emergency procedure (OR = 1.99); intensive-care unit stay prior to surgery (OR = 2.6); and antimicrobial prophylaxis administered 2 or more hours before operation (OR = 5.3).

In general, antimicrobial prophylaxis protects against SWI (OR = 0.5); however, administration 2 hours or more before the operation increases the risk of SWI by a factor of 5.3. Therefore, measures should be taken to ensure the correct timing of antimicrobial prophylaxis.