1343 - Clinical Outcome of Penicillin Skin Testing as an Antimicrobial Stewardship Initiative in the pre-surgical clinic in a community hospital.

Background: Penicillin (PCN) allergy is a serious adverse reaction that prevents use of first line therapy. 10% of the population reports a PCN allergy, however less than 1% is truly allergic. Elimination of false allergies significantly impacts patient’s lives and decreases antimicrobial resistance and cost. Penicillin Skin Testing (PST) is a tool to support antimicrobial stewardship (ASP) and to optimize allergy de-labeling. The goal of this pilot study was to implement a pharmacy-nurse driven PST service in the outpatient pre-surgical clinic in a community hospital and to assess the impact of PST on the usage of vancomycin as the pre-op prophylaxis agent.

Methods: In May 2019 a single-center, prospective pilot in the outpatient clinic for pre-surgical adult patients with a documented PCN allergy was approved. Patients were identified via a PCN allergy report, generated from the electronic medical record and interviewed by the ASP pharmacist to identify the type of reaction. The study excluded patients if they were unable to give informed consent, if they took anti-histamines within 72 hours of the test, or if the allergy is clinically insignificant. The nurse administered the test and the ASP pharmacist read the results, documented them in the system, and counseled patients.

Results: A total of 155 patients with PCN allergy qualified for PST and only one patient had a true allergy. 154 patients had a negative test and their allergy was deleted in their electronic health system. In addition, those patients received cefazolin as the antibiotic of choice before their surgery which is narrower spectrum and has less side effects compared to vancomycin. Furthermore, all patients were counseled and acknowledged the impact of the results. After performing PST there was an overall 39% decrease in vancomycin DOT/1000 in the surgical population (2018 May-Dec Average DOT/1000 patient Days=3.75 vs 2019 May-Dec Average DOT/1000 patient Days=2.3. (p < 0.005) )

Conclusion: The PST service offers an efficient method to collect a detailed PCN allergy history and de-label patients accordingly. PST helps reduce the pre-surgical prophylaxis use of broad spectrum agents and allergy testing significantly increases patient satisfaction