ISR 11 - Effect of a Standardized Preoperative Prophylactic Antimicrobial Guideline on Improved Postoperative Surgical Site Infection (SSI) Outcomes

Background: SSIs contribute to increased patient mortality, prolonged hospital stays, and readmission. Preoperative antimicrobial prophylaxis is a key prevention strategy to minimize infection risk. Proper selection of antibiotics, administered at the appropriate time and in the correct dosage, significantly decreases the incidence of SSIs.

Methods: In 2019, an SSI prevention bundle was implemented across our multi-hospital health system. Appropriate selections of preoperative antibiotics, dose, administration times, and redose were evaluated for 71,153 colon (COLO), abdominal hysterectomy (HYST), hip and knee arthroplasty (HPRO/KPRO) cases from January 2019–November 2023. SSI rates and Standardized Infection Ratios (SIR) were captured as outcomes. SSIs were validated to the National Healthcare Safety Network (NHSN) surveillance definitions.

Results: Cases compliant with preoperative antimicrobial prophylaxis realized a 0.88% decrease in mortality rate. The average length of stay (LOS) decreased by 2.33 days, and the readmission rate decreased by 3.15%.

For COLO procedures, as antimicrobial prophylaxis increased by 21.03%, SSI rates inversely decreased by 0.68%. Similarly, for HYST procedures, antimicrobial prophylaxis increased by 8.7%, associated with a decrease in SIR by 0.078.

Adherence to antimicrobial prophylaxis strategies proved most efficacious with orthopedic SSIs which saw increased compliance by 7.40% in HPRO and 5.7% in KPRO. For HPRO, SSI rates decreased by 0.45% and SIR by 0.581. For KPRO, SSI rates decreased by 0.12% and SIR by 0.414.

In a one-tailed paired t-test, the relationship between compliance with preoperative antimicrobial prophylaxis proved to have a statistically significant SIR reduction for COLO, HPRO, and KPRO.

Conclusions: Through a focused approach to preoperative antimicrobial prophylaxis, our health system implementations are demonstrating an improvement in mortality rates, average LOS, readmission rates, and SSI rates. Robust monitoring of each metric positively influences the success of this bundle. Future analysis is underway to review PowerPlan utilization to improve adherence to this prevention strategy.