Emergency department vancomycin use: Dosing practices and associated outcomes

Background: Emergency Department (ED) dosing of vancomycin and its effect on outcomes has not been examined. Study Objective: To describe current vancomycin dosing practices for ED patients, focusing on patient factors associated with administration, dosing accuracy based on patient body weight, and clinical outcomes. Methods: Single-center, retrospective cohort study of vancomycin administered in the ED over 18 months in an academic, tertiary care ED. Data were collected on 4656 patients. Data were analyzed using a generalized estimating equations model to account for multiple doses being administered to the same patient. Results: The ED dose was continued, unchanged, in 2560 admitted patients (83.8%). The correct dose was given 980 times (22.1%), 3143 doses (70.7%) were underdosed, and 318 were overdosed (7.2%). Increasing weight was associated with underdosing (adjusted odds ratio 1.52 per 10 kg body weight, p < 0.001). Patients who received doses of vancomycin > 20 mg/kg had longer hospital length of stay (p = 0.005); were more likely to spend ≥ 3 days in the hospital (odds ratio [OR] 1.49; 95% confidence interval [CI] 1.12-1.98, p = 0.006); and more likely to die (OR 1.88; 95% CI 1.22-2.90, p = 0.004). Conclusion: In this largest study to date examining ED vancomycin dosing, vancomycin was commonly given. Dosing outside the recommended range was frequent, and especially prevalent in patients with a higher body weight. The ED dose of vancomycin was frequently continued as an inpatient, regardless of dosing accuracy. There is significant room for improvement in dosing accuracy and indication. Vancomycin dosing in the ED may also affect clinical outcomes.