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Pharmacy and Pharmaceutical Sciences


Emily Fox, PharmD, PGY-1 Pharmacy Resident

Brent Footer, PharmD, BCPS; Angel Mendez, Pharmacy Student

Providence Portland Medical Center, Portland, Oregon

Evaluation of surgical antibiotic prophylaxis at a large, tertiary medical center

Surgical site infections (SSI) are a significant cause of morbidity, prolonged hospitalization, and mortality. The cost of a single SSI is estimated to be upward of $25,000 and increases a patient’s length of hospital stay by ~10 days. Our institution has identified inappropriate or less than optimal antimicrobial prophylaxis as a potential contributor in several recent SSI cases. Current literature on this topic has found that there may be a role for clinical pharmacists in cyclic auditing to improve surgical antibiotic prophylaxis guideline adherence. This retrospective analysis of hysterectomy, colorectal, and spinal surgeries aims to review surgical antimicrobial prophylaxis for appropriateness based on patient-specific factors and published system and national guidelines.

This is an IRB-approved, single institution retrospective chart review of surgical antibiotic prophylaxis regimens for adult patients that underwent hysterectomy, colorectal, or spinal surgery between the months of June and August 2019. Specific surgery types were chosen based on requests by surgery leadership and highest potential for quality improvement. Patients were identified by surgery classification via the electronic medical record (EMR). Other relevant data was obtained via the EMR including: surgeon, anesthesiologist, antibiotic regimen, dose, administration time, ordering method, and patient weight. Additional chart review was required for other relevant factors including history of multi-drug resistant organisms and allergy history/severity. The primary outcome measured was compliance to hospital system guidelines, accounting for antibiotic selection, administration timing, and dosing.

Primary outcome adherence rates varied greatly depending on the type of surgery. For hysterectomy, 62 of 141 surgeries (44%) achieved the primary outcome, with the primary contributor of non-compliance being selection of an antibiotic regimen inconsistent with system-wide guidelines. For colorectal surgeries, 21 of 35 (60%) achieved the primary outcome, with the primary reason for non-compliance being inappropriate antibiotic administration timing. Additionally, it was identified that history of resistant infections was not properly accounted for when making antibiotic prophylaxis choices, with 3 SSIs resulting from multi-drug resistant organisms in patients with MDRO history. Spinal surgery compliance to the primary outcome was less-clear, as guidelines are not as well-defined. However, MRSA colonization status was not determined via PCR when appropriate for 31 of 148 (21%) of surgeries.

Opportunities for pharmacist intervention and education were identified for implementation after chart review of each surgery. Each surgery requires a unique intervention. Primary outcome data and proposed interventions for each surgery was presented to the institutional surgical site infection committee, which met quarterly. Pharmacist cyclic auditing of antibiotic prophylaxis choices resulted in increased discussion and education. Proposed changes are still being considered by surgery department leadership, including a change in antibiotic choice for colorectal surgeries. Future data collection will be performed after changes are implemented to determine improved guideline adherence.




Graduate Medical Education

Conference / Event Name

Academic Achievement Day, 2020


Providence Portland Medical Center, PGY-1 Pharmacy Residency Program

Evaluation of surgical antibiotic prophylaxis at a large, tertiary medical center