Katie Elder1, David M Hill2, William L Hickerson3. 1. Department of Pharmacy, Regional One Health, 877 Jefferson Avenue, Memphis, TN 38103, USA. 2. Director of Burn Research, Firefighters Burn Center; Clinical Pharmacist, Department of Pharmacy, Regional One Health, 877 Jefferson Avenue, Memphis, TN 38103, USA; Assistant Professor, Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Ave, Memphis, TN 38163, USA. Electronic address: dmhill@regionalonehealth.org. 3. Medical Director, Department of Plastic Surgery, Firefighters Regional Burn Center, Regional One Health, 877 Jefferson Avenue, Memphis, TN 38103, USA; Professor, Department of Plastic Surgery, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38103, USA. Electronic address: whicker1@uthsc.edu.
Abstract
OBJECTIVE: To characterize the pharmacokinetics of vancomycin dosing in thermal or inhalation injury as they relate to percent total body surface area burn (TBSA) and days since injury (DSI). METHODS: This retrospective 3-year study included patients with thermal or inhalation injury receiving vancomycin. Patient demographics and course data were collected using the institution's electronic medical record. RESULTS: Six hundred and fifty-four patients were included in the study; 124 remained after exclusion. Clearance (CL) was augmented in patients closer to their date of injury. CL and total daily dose requirements significantly increased with larger percent TBSA injured that was independent of volume of distribution (Vd). Larger percent TBSA also predicted increased occurrence of renal injury prior to vancomycin initiation. A modified sample set was also analyzed to control for renal dysfunction. Creatinine clearance (CrCl) estimated via the Cockcroft-Gault equation significantly impacted CL and total daily dose. To obtain a goal trough of 15-20mg/L, the average patient in the modified sample with ≥10% TBSA required 64.7mg/kg/day (or 16.2mg/kg every 6hours). CONCLUSIONS: DSI, percent TBSA, and CrCl can be used to predict faster vancomycin CL and need for higher total daily doses. Augmented pharmacokinetics can occur as early as two days after injury and decrease with time. Acceptable target trough attainment is still lacking and this data should assist in performance improvements for initial vancomycin dosing.
OBJECTIVE: To characterize the pharmacokinetics of vancomycin dosing in thermal or inhalation injury as they relate to percent total body surface area burn (TBSA) and days since injury (DSI). METHODS: This retrospective 3-year study included patients with thermal or inhalation injury receiving vancomycin. Patient demographics and course data were collected using the institution's electronic medical record. RESULTS: Six hundred and fifty-four patients were included in the study; 124 remained after exclusion. Clearance (CL) was augmented in patients closer to their date of injury. CL and total daily dose requirements significantly increased with larger percent TBSA injured that was independent of volume of distribution (Vd). Larger percent TBSA also predicted increased occurrence of renal injury prior to vancomycin initiation. A modified sample set was also analyzed to control for renal dysfunction. Creatinine clearance (CrCl) estimated via the Cockcroft-Gault equation significantly impacted CL and total daily dose. To obtain a goal trough of 15-20mg/L, the average patient in the modified sample with ≥10% TBSA required 64.7mg/kg/day (or 16.2mg/kg every 6hours). CONCLUSIONS: DSI, percent TBSA, and CrCl can be used to predict faster vancomycin CL and need for higher total daily doses. Augmented pharmacokinetics can occur as early as two days after injury and decrease with time. Acceptable target trough attainment is still lacking and this data should assist in performance improvements for initial vancomycin dosing.