LAUSR

Critical Care Medicine • Volume 46 • Number 1 (Supplement) www.ccmjournal.org Learning Objectives: Augmented renal clearance (ARC) is a syndrome characterized by enhanced glomerular filtration of solutes and medications in the nephron. ARC has been observed to occur in over 60% of critically ill patients. Unfortunately, many common biomarkers do not reliably detect ARC. As a result, scoring tools such as the ARCTIC score have been developed to better identify patients at risk. Aminoglycosides are antibiotics that undergo glomerular filtration with minimal tubular reabsorption or secretion in the nephron. As such, clearance of aminoglycosides can accurately quantify estimated glomerular filtration rate (eGFR) in patients. Methods: Patients who received tobramycin dosed at 3 milligrams per kilogram admitted to the surgical or medical intensive care unit between July 2014 and June 2016 at a tertiary care center were included. Patients receiving continuous renal replacement therapy were excluded. Using two tobramycin levels collected after medication administration, pharmacokinetic parameters including clearance were calculated. A calculated eGFR greater than 125 milliliters per minute was defined as ARC. Calculated eGFR was then compared with ARCTIC score. An ARCTIC score greater than or equal to 7 was defined as high risk for ARC. Results: The overall cohort included 226 patients. Using the ARCTIC tool, 19.4% of patients were identified to be at high risk. ARC was detected in 10.7% of patients using eGFR calculated by tobramycin clearance. Among patients identified to be experiencing ARC using tobramycin clearance, only 54.1% met high risk criteria when the ARCTIC tool was applied. Patients experiencing ARC were younger, had lower serum creatinine values, and were less likely to have sepsis. Conclusions: In a critically ill medical/surgical patient population, there is poor correlation between ARCTIC score to identify patients at risk for ARC and objective measurement of eGFR using tobramycin clearance. When aminoglycosides are administered to the critically ill, it may be useful to use drug levels to help estimate renal function.