72: Antimicrobial stewardship in patients with penicillin allergy undergoing hysterectomy

To evaluate the rate and predictors of appropriate prophylactic antibiotic administration prior to hysterectomy performed for benign indications in patients with penicillin allergy. A retrospective cohort study was performed for patients with self-reported penicillin allergy who underwent a hysterectomy for benign indications at an academic tertiary institute in 2018. All surgical modalities including vaginal, laparoscopic, robotic-assisted and open surgery were included. The primary outcome was appropriate pre-operative antibiotics based on the American College of Obstetrician and Gynecologists guidelines. Secondary outcomes included post-operative surgical site infection. We collected data on the patients’ self-reported penicillin allergy, list of allergies, medical comorbidities and perioperative data. Standard analysis for descriptive data was performed, and a multivariable logistic regression was fit to determine predictors for receiving appropriate preoperative antibiotics. In 2018, a total of 230 patients with penicillin allergy underwent a hysterectomy for benign indications. The most common self-reported allergic reaction to penicillin was hives (n=68, 29.6%) followed by rash (n=66, 28.7%) and unspecified (n=42, 18.3%). Appropriate antibiotics were administered in 42.2% (n=97) of patients versus inappropriate antibiotics in 57.8% (n=133) of patients (Table 1). For patients who did not receive appropriate antibiotics, they most commonly received Ciprofloxacin and Metronidazole (n=66) followed by non-standard regimens (n=45). In this cohort, 2.6% (n=6) of patients had a post-operative surgical site infection. One patient (1.0%) in the appropriate antibiotic group developed surgical site infection; in contrast, four patients (3.0%) in the inappropriate antibiotic group developed surgical site infection (p=0.40). Age, race, BMI, and ASA class had no impact on appropriate antibiotic administration. On multivariable logistic regression, the odds of having appropriate antibiotics were 0.16 times lower among MRSA carriers (CI 0.03-0.91; p =0.04), 2.50 times higher among those with three or more antibiotic allergies (CI 1.15-5.42; p=0.02), 1.97 times higher among those with at least one comorbidity (CI 1.06-3.67; p=0.03), 8.94 times higher if anaphylaxis was the reported allergy (CI 3.53-22.63; p=<0.001), and 6.24 times higher if the reported allergy was hives (CI 3.17-12.29; p=<0.001). Over half of patients with penicillin allergy undergoing hysterectomy received inappropriate prophylactic antibiotics. Patients with more medical comorbidities, greater number of antibiotic allergies, and IgE-mediated hypersensitivity reactions to penicillin (anaphylaxis and hives) had higher odds of receiving appropriate prophylaxis.