Antibiotic Stewardship Interventions Improve Choice of Antibiotic Prophylaxis in Total Joint Arthroplasty in Patients with Reported Penicillin Allergies.

BACKGROUND Most patients who report a penicillin allergy can tolerate cefazolin, the preferred prophylaxis in a total joint arthroplasty (TJA). Regardless, patients with a reported penicillin allergy are less likely to receive first-line perioperative antibiotics as a result of inaccurate penicillin allergy documentation and misconceptions regarding cross-reactivity between penicillin and cephalosporins. The over-reporting of penicillin allergies and the safety of cephalosporins in patients with reported penicillin allergies have been well established throughout the evidence [13]. QUESTIONS/PURPOSES The study sought to answer two questions: (1) Do antibiotic stewardship interventions improve adherence to appropriate prophylactic antibiotic usage in patients with a documented penicillin allergy undergoing primary TJA? (2) What is the risk of allergic or adverse reactions secondary to cefazolin use in patients with a documented penicillin allergy? METHODS This was a single-center, retrospective study of orthopaedic patients older than 18 years who underwent a primary elective TJA at a 261-bed community hospital. The study had two periods: the preintervention period ran from March 1, 2017 to August 30, 2017 and the postintervention period was from March 1, 2019 to August 30, 2019. A total of 396 patients with a history of a documented penicillin allergy underwent a THA or TKA during the study periods. After reviewing every fourth patient with a history of a documented penicillin allergy who met study inclusion criteria and excluding those patients who had a codocumented cephalosporin allergy, a total of 180 patients with a documented penicillin allergy were evaluated (90 patients in the preintervention group and 90 patients in the postintervention group). To answer our first study question, regarding whether antibiotic stewardship interventions improve adherence to appropriate prophylactic antibiotic usage in patients with a documented penicillin allergy undergoing primary TJA, we evaluated appropriate antibiotic usage pre- and postintervention. To answer our second study question, concerning the risk of allergic or adverse reactions secondary to cefazolin use in patients with a documented penicillin allergy, we reviewed signs of allergic reactions in patients who received cefazolin for a primary TJA and had a documented penicillin allergy. RESULTS Postintervention antibiotic use was more appropriate (91% [82 of 90] versus 54% [49 of 90], risk ratio 1.67 [95% confidence interval 1.37 to 2.04]; p < 0.01), particularly in patients with nonsevere allergy (preintervention: 47% [36 of 76] versus postintervention: 96% [76 of 79]; p < 0.01). No patients had signs of an allergic reaction related to cefazolin, including eight patients with severe penicillin allergy. CONCLUSION A multifaceted antibiotic stewardship intervention increased the appropriateness of antibiotic prophylaxis in elective primary TJA. Patients with nonsevere penicillin allergies, even those reporting hives or local swelling, tolerated cefazolin. Antibiotic stewardship interventions can be implemented across institutions to expand cephalosporin use in patients with a reported penicillin allergy within orthopaedic TJA patients. LEVEL OF EVIDENCE Level III, therapeutic study.