COMPARATIVE STUDY OF βS-LACTAM DE-LABELING ON THE FREQUENCY OF PERI-OPERATIVE VANCOMYCIN USE

Abstract

Introduction Vancomycin is the antibiotic of choice in β-lactam allergic adults undergoing surgical antibiotic prophylaxis. Because it is a suboptimal option, in 2015 a pre-operative drug allergy screening program began at the Montreal General Hospital (MGH). It de-labeled 94 % of patients evaluated, reducing vancomycin use to 3 %. To validate the program effectiveness a prospective study comparing the Royal Victoria Hospital (RVH), which lacked de-labeling was undertaken.The aim of the study was to determine the effect of a de-labeling program on vancomycin use. Methods From Jan 1st to Dec 31st 2017 pre-surgical patients suspected of penicillin allergy at both hospitals were studied. Variables captured included; gender, age, time, type, place of surgery, prophylactic antibiotics and number/type of postoperative infections. Results Among 618 RVH patients with suspected β-lactam allergy, 385 received peri-operative antibiotics and 175 got vancomycin (only one had Methicillin Resistant Staphylococcus Aureus (MRSA)). Of the 31 post-operative infectious complications, 20 (65%) occurred in those administered vancomycin. Among the 658 MGH patients with suspected β-lactam allergy 116 had pre-operative allergy assessments of which 98 got antibiotics. Vancomycin was given peri-operatively to 4 patients (none MRSA positive). Cefazolin in 84 and no antibiotics in 18.Only 3 patients (3 %) had post-operative complications but none on vancomycin. Vancomycin prophylaxis was higher at the RVH (175 of 385,45.45%) versus MGH (4 of 98,4.08%), with a difference of 41.37% (95%CI, 34.40%, 48.34 %). Conclusions Lack of β-lactam allergy screening was associated with a significantly higher frequency of vancomycin use and higher rates of post-operative complications.