96 - Surgical Site Infection Prophylaxis Selection and Postoperative Clinical Outcomes in Patients with Reported Penicillin Allergy

Background: Administration of preoperative antibiotics are known decrease risk of postoperative surgical site infections (SSI) and deviation from first line prophylaxis increases this risk. Patients who report penicillin (PCN) allergy are less likely to receive cefazolin preoperatively despite being the preferred antibiotic for SSI prevention in the majority of surgical procedures.

Methods: A single center retrospective descriptive study was performed during the 2018-2019 academic year. Perioperative antimicrobial administration practice was evaluated for all types of surgical procedures. Patient demographics, PCN allergy history, development of Clostridioides difficile infection (CDI) within 90 days of procedure, and total hip and knee arthroplasty SSIs were assessed.

Results: During the study period, 16,376 procedures were performed with perioperative antibiotic administration. Cefazolin (12,756; 77.9%) was most frequently administered followed by clindamycin (1,396; 8.5%), and vancomycin (735, 4.5%). PCN allergy was reported in 2,051 (12.5%) patients, of which 1,180 (57.5%) had record of previously receiving a cephalosporin. Interestingly, 694 (33.8%) and 11,799 (82%) patients with and without a reported PCN allergy respectively received cefazolin perioperatively (P< 0.001). The incidence of joint replacement SSI was higher in patients with a reported PCN allergy (6 of 97; 6.2%) compared to those without (12 of 671; 1.8%) (P=0.018). CDI occurred in 44 (1.1%) of 3,883 and 70 (0.5%) of 12,493 patients who received a non-cefazolin or cefazolin respectively for prophylaxis (OR 2.1; 95% CI 1.5-2.9). In multivariate analysis controlling for surgery type, age, weight, and renal function, receipt of a non-cefazolin antibiotic was independently associated with developing CDI (OR 1.6; 95% CI 1.1-2.4).

Conclusion: Patients with a reported PCN allergy were more likely to receive a non-cefazolin antibiotic perioperatively and were more likely to develop a SSI following hip or knee replacement. Administration of a non-cefazolin antibiotic was independently associated with increased risk of CDI. Efforts should be made to minimize inappropriate avoidance of first line perioperative prophylaxis due to reported PCN allergies.