1570. Association Between Vancomycin Area Under the Curve (AUC) and Nephrotoxicity

BACKGROUND: It is unclear whether increased vancomycin area under the curve (AUC) contributes to acute kidney injury (AKI) risk. METHODS: This retrospective cohort study was undertaken to determine whether vancomycin AUC > 550 is associated with a higher rate of AKI than an AUC < 550. Patients treated with vancomycin for at least 4 days at the St. Louis VA from 1/1/2016–9/31/2018 were included. The primary outcome was AKI (defined as an increase in serum creatinine by 0.3 mg/dL or 50% from baseline). Secondary outcomes included length of stay, readmission, or mortality in 30 days, AKI rate with concurrent antibiotics, and AKI rate with comorbidities. The AUC was calculated as daily dose (in mg) divided by vancomycin clearance. The variables of age ≥ 70, vancomycin AUC ≥ 550, creatinine clearance (CrCl) < 50 mL/minute, concomitant antibiotic administration, vancomycin treatment ≤ 7 days, and the presence of comorbidities were included in a bivariate analysis. Variables with a P-value of <0.2 were included in a multivariate logistic regression model. RESULTS: Two hundred patients were included in the analysis; 100 patients with an AUC ≥ 550, and 100 with an AUC < 500. Only mean vancomycin dose (1722.50 mg vs. 2361.25 mg; P < 0.05), mean AUC (465.88 vs. 696.45; P < 0.05), and peak SCr (1.22 mg/dL vs. 1.48 mg/dL; P = 0.015) were significantly different between groups; AUC < 550 vs. AUC ≥ 550, respectively. Acute kidney injury occurred in 22% (44/200) of all patients; 42% (42/100) with a calculated AUC ≥ 550 developed AKI compared with 2% (2/100) of patients with an AUC < 550 (P < 0.05). The secondary outcomes of concomitant nephrotoxic agents, length of stay, readmission at 30 days, and 30-day mortality were not significantly different between groups. Only age ≥ 70, vancomycin AUC ≥ 550, CrCl < 50 mL/minute, concomitant piperacillin–tazobactam administration, and the presence of comorbidities were included in the multivariate regression. Age ≥ 70, CrCl < 50 mL/minute, and AUC ≥ 550 [OR 49.5 (95% CI 10.1 – 242.3; P < 0.05)] were found to be independently associated with risk for developing AKI. CONCLUSION: Patients with a calculated vancomycin AUC ≥ 550 were found to have a significantly higher rate of AKI compared with those with an AUC < 550. DISCLOSURES: All authors: No reported disclosures.