Risk factors for postoperative infection

Area of Science:

• Infectious Disease Epidemiology
• Surgical Site Infection Surveillance
• Antimicrobial Stewardship

Background:

• Postoperative wound infections (PWIs) pose a significant risk to surgical patients.
• Identifying critical risk factors and understanding infection etiology are crucial for effective prevention and treatment.

Purpose of the Study:

• To identify independent risk factors for PWIs.
• To analyze the impact of perioperative antibiotics on PWI bacteriology.

Main Methods:

• Prospective collection of epidemiologic data and intraoperative wound cultures from 1,852 patients over 4 years.
• Stepwise logistic regression analysis to determine predictive risk factors for PWI.
• Comparison of PWI characteristics between patients who received perioperative antibiotics and those who did not.

Main Results:

• Four independent risk factors for PWI were identified: surgical wound class, American Society of Anesthesiologists physical status, duration of surgery, and intraoperative culture results.
• Positive intraoperative cultures had limited clinical utility due to low predictive value (32%) and high false-positive rates (82%).
• Patients receiving perioperative antibiotics who developed infections were often infected with resistant organisms.

Conclusions:

• Surgical wound class, ASA status, surgery duration, and intraoperative cultures are key predictors of PWI.
• Intraoperative cultures have low clinical utility for predicting PWI.
• Perioperative antibiotic use may be associated with infections caused by resistant pathogens, necessitating careful consideration of antibiotic stewardship.