629. Vancomycin AUC:MIC-Based Dosing is Associated with Significantly Less Acute Kidney Injury in Patients Admitted to a Burn Intensive Care Unit

Abstract Background Vancomycin is often used for empiric coverage of methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin is well known to cause acute kidney injury (AKI), which can be detrimental to patients in the intensive care unit (ICU) setting. In 2020, the American Society of Health-systems Pharmacists updated their vancomycin dosing guidelines to target an area under the plasma concentration-time curve to minimum inhibitory concentration ratio (AUC:MIC) of 400-600 mg*h/L, a change from targeting a trough concentration of 10-20 mg/L. This suggests that vancomycin toxicity is likely minimized using the AUC:MIC ratio. Methods This retrospective cohort study compares the incidence of AKI in patients admitted to the burn ICU dosed to achieve a target to those dosed to achieve an AUC:MIC goal. Incidence of AKI, per the AKIN criteria, was recorded. Known risk factors such as history of hypertension, concomitant furosemide use, pre-existing renal insufficiency, and other concomitant nephrotoxins were considered. All data collected were previously obtained as a part of usual practice. Results Two hundred thirty-six subjects who received 317 courses of vancomycin were included. One hundred twenty courses were dosed to achieve an AUC goal, and 197 courses were dosed to achieve a trough goal. In the AUC group, 49 (57.7%) subjects were admitted for burns, 21 (24.7%) were admitted for necrotizing soft tissue infection (NSTI), and 15 (17.7%) were admitted for other reasons. In the trough group, 97 (64.7%) were admitted for burns, 22 (18.7%) for NSTI, and 25 (16.7%) for other reasons. Demographics were similar between the two groups. The incidence of AKI was 10.3% in the AUC group, as compared to 20.3% in the trough group (p=0.0171). Patients in the AUC group received significantly less vancomycin than in the trough group (3524 ± 1551 vs 3145 ± 1491, p=0.0315). Risk factors for AKI were similar between the two groups (55.6% vs 52.8%, p=0.6347), and concomitant nephrotoxin exposure was similar (52.6% vs 42.7%, p=0.0924). Conclusion Using AUC:MIC-based dosing was associated with a decreased incidence of AKI than trough-based dosing in patients admitted to the burn ICU. Disclosures All Authors: No reported disclosures.