In 2019, the VISN 8 ASPWG created a comprehensive vancomycin AUC toolkit to facilitate implementation. Components included a pharmacokinetic management policy and procedure, a vancomycin dosing guide, a progress note template, educational materials specific to pharmacy, nursing, laboratory, and medical services, a pharmacist competency examination, and a vancomycin AUC calculator (eAppendix). Each component was developed by a subgroup with the understanding that sites could incorporate variations based on local practices and needs.
FIGURE Vancomycin Area Under the Curve Dosing Calculator
The vancomycin AUC calculator was developed to be user-friendly and included safety validation protocols to prevent the entry of erroneous data (eg, unrealistic patient weight or laboratory values). The calculator allowed users to copy data into the electronic health record to avoid manual transcription errors and improve operational efficiency. It offered suggested volume of distribution estimates and 2 methods to estimate elimination constant (Ke ) depending on the patient’s weight. 9,10 Creatinine clearance could be estimated using serum creatinine or cystatin C and considered amputation history. The default AUC goal in the calculator was 400 to 550 mcg*h/mL. This range was chosen based on consensus guidelines, data suggesting increased risk of AKI with AUCs > 515 mcg*h/mL, and the preference for conservative empiric dosing in the generally older VA population. 11 The calculator suggested loading doses of about 25 mg/kg with a 2500 mg limit. VHA facilities could make limited modifications to the calculator based on local policies and procedures (eg, adjusting default infusion times or a dosing intervals).
The VISN 8 Pharmacy Pharmacokinetic Dosing Manual was developed as a comprehensive document to guide pharmacy staff with dosing vancomycin across diverse patient populations. This document included recommendations for renal function assessment, patient-specific considerations when choosing an empiric vancomycin dose, methods of ordering vancomycin peak, trough, and surveillance levels, dose determination based on 2 levels, and other clinical insights or frequently asked questions.
ASPWG members presented an accredited continuing education webinar for pharmacists, which reviewed the rationale for AUC-targeted dosing, changes to the current pharmacokinetic dosing program, case-based scenarios across various patient populations, and potential challenges associated with vancomycin AUC-based dosing. A recording of the live training was also made available. A vancomycin AUC dosing competency test was developed with 11 basic pharmacokinetic and case-based questions and comprehensive explanations provided for each answer.
VHA facilities implemented AUC dosing in a staggered manner, allowing for lessons learned at earlier adopters to be addressed proactively at later sites. The dosing calculator and education documents were updated iteratively as opportunities for improvement were discovered. ASPWG members held local office hours to address questions or concerns from staff at their facilities. Sharing standardized materials across the VISN reduced individual site workload and complications in rolling out this complex new process.
VISN-WIDE QUALITY ASSURANCE
At the time of project conception, 4 of 7 VISN 8 health systems had transitioned to AUC-based dosing. A quality assurance protocol to compare patient outcomes before and after changing to AUC dosing was developed. Each site followed local protocols for project approval and data were deidentified, collected, and aggregated for analysis.