Acute kidney injury associated with area under the curve versus trough monitoring of vancomycin in obese patients.

Vancomycin is a first-line agent used in the treatment of methicillin-resistant Staphylococcus aureus; however, vancomycin is associated with acute kidney injury (AKI). Previous literature demonstrates decreased incidence of AKI using 24-hour area under the concentration-time curve (AUC24) monitoring, but its safety is unknown in obese populations. Patients ≥18 years, with Body Mass Indices (BMI) ≥30 kg/m2, admitted between August 2015-July 2017 or October 2017-September 2019, who received vancomycin for ≥72 hours and had level(s) drawn within 96 hours of initiation were included. The primary outcome was incidence of AKI. Secondary outcomes included inpatient mortality rate, median inpatient length of stay, median vancomycin trough concentration, and median vancomycin AUC24. AKI was identified using the highest serum creatinine value compared to the value immediately prior to vancomycin initiation based on Kidney Disease Improving Global Outcomes (KDIGO) criteria. Overall, 1024 patients met inclusion criteria, with 142 out of 626 patients in the trough group and 65 out of 398 patients in the AUC24 group meeting criteria for AKI (22.7% vs. 16.3%, p=0.008). Logistic regression of the data to account for confounding factors maintained significance for the reduction in incidence of AKI with AUC24 monitoring compared to trough monitoring (p=0.010). Monitoring of vancomycin with AUC24 was associated with a decreased risk of AKI when compared with trough monitoring in obese patients.