Category: Professional Posters
Purpose: Appropriate vancomycin dosing is critical to achieve successful antimicrobial treatment. The Infectious Disease Society of America recommends that vancomycin dosing be actual weight based, even in the obese population. Because of vancomycin’s relatively long half-life, loading doses of 20 to 30 mg per kg (maximum 2000 mg) are recommended in order to achieve effective therapeutic concentrations quickly. To facilitate this approach our facility implemented an order set and counseled prescribers on the importance of weight based dosing. An analysis was conducted comparing vancomycin loading doses before and after implementation of the order set and physician education.
Methods: A vancomycin order set was implemented in June of 2018 to facilitate adult weight based dosing, including initial loading doses of 20 to 30 mg per kg. The emergency department pharmacists promoted the use of this order set, assisted with order entry, and advised prescribers on the importance of appropriate weight based dosing in achieving therapeutic vancomycin serum concentrations. Vancomycin utilization reports were produced from the pharmacy computer system for June, July, and August of 2017 and 2018. Initial orders with a frequency of ‘once’ were analyzed. The following data were collected: dose, patient weight, serum creatinine at baseline, 24 hours, 48 hours, and 72 hours. It was then determined if the dose ordered was 20 to 30 mg per kg, 15 to 20 mg per kg or less than 15 mg per kg. A sub-analysis was performed on patients who experienced acute kidney injury post loading dose. Acute kidney injury was defined as an increase of serum creatinine of 0.3 mg/dL or greater at either 24 or 48 hours post baseline, or equal to or greater than 1.5 times baseline at any of the data points collected. Data from 2017 and 2018 data were compared to see if there was a difference in prescriber behavior.
Results: A total of 273 initial one time doses of vancomycin were identified in 2017 and 304 in 2018. In 2017, 23 doses (8.4 %) were in the 20 to 30 mg per kg range, 76 doses (27.8%) were in the 15 to 20 mg per kg range, and 174 (63.7%) were below 15 mg per kg. In 2018, 110 doses (36 %) were in the 20 to 30 mg per kg range, 73 doses (24%) were in the 15 to 20 mg per kg range, and 121 (39.8%) were below 15 mg per kg. There were 43 (16%) and 41 (13%) cases of acute kidney injury in 2017 and 2018, respectively. Of the 43 cases from 2017 11.6% received doses of 20-30 mg per kg, 23.3% received doses of 15-20 mg per kg, and 65.1% received doses of less than 15 mg per kg. Of the 41 cases from 2018, 36.6% received doses of 20-30 mg per kg, 29.3% received doses of 15-20 mg per kg, and 34.1% received doses of less than 15 mg per kg.
Conclusion: Implementation of a vancomycin order set in combination with prescriber education increased the frequency of appropriate weight based loading doses of vancomycin, with no concomitant increase in acute kidney injury.