Vancomycin Use in Patients Discharged From the Emergency Department: A Retrospective Observational Cohort Study

Abstract

Background Infections due to methicillin-resistant Staphylococcus aureus (MRSA) are associated with significant morbidity and mortality and are typically treated with intravenous vancomycin. Given vancomycin’s time dependent mechanism of action, it is unlikely that vancomycin administration in the ED prior to disposition home could be beneficial. Study Objectives To characterize the indications, dosing, and appropriateness of vancomycin use in patients discharged from the Emergency Department (ED). Methods This is a single-center retrospective observational cohort study of patients who received vancomycin in an urban, academic, tertiary care ED. The subjects were consecutive adult patients administered intravenous vancomycin in the ED and then discharged home over an 18-month period. Outcomes were measured 1) to characterize patients receiving vancomycin prior to discharge home from the ED; and 2) to identify patients that did not meet indications for appropriate use based on the 2011 ISDA guidelines for treating MRSA infections Results 526 patients received vancomycin in the ED prior to discharge during the study period. In this cohort, 368 (70%) patients were diagnosed with skin and soft tissue infections. A MRSA risk factor was present in 396 (75%) patients. Prior to discharge, one dose of vancomycin was administered to 357 (68%) patients. Underdosing of vancomycin occurred in 239 (73%) patients. Conclusions Vancomycin was given frequently to patients discharged home from the ED, most commonly for conditions where vancomycin was not indicated, such as skin and soft tissue infections. The majority of these patients received a vancomycin dosing strategy that is not only unlikely to lead to clinical improvement, but also has the potential to contribute adversely to the development of antibiotic resistance. Further investigation is needed into the impact of vancomycin use on the emergence vancomycin resistance and the role of ED based antibiotic stewardship.

Commentary

“…7 With regard to vancomycin use in the ED, one ED-based observational study conducted in 2008 to 2010 identified the frequent and questionably effective practice of administration of a single dose of vancomycin before patient discharge with oral antibiotics, as well as frequent vancomycin underdosing. 8 For treatment of most nonobese patients with normal renal function who have skin and soft tissue infections severe enough to require hospital admission, standard vancomycin dosing of 1 g every 12 hours is recommended. However, for other syndromes, such as severe sepsis and pneumonia in which MRSA is suspected, weight-based dosing of 15 to 20 mg/kg per dose with monitoring of trough levels is recommended, and, for critically ill patients, this would be preceded by an initial loading dose of 25 to 30 mg/kg (actual body weight).…”

Antimicrobial Stewardship in the Emergency Department

“…Another situation that supports the need for an ED-based ASP service is the frivolous administration of vancomycin in the ED. Mueller et al [ 30 ] reported in their single-center study that 68% of patients received one-time doses of vancomycin prior to discharge, whereby 73% of these patients were under-dosed with <15 mg per kg of body weight. This study highlights the real possibility of developing resistance if these prescribing behaviors are not addressed.…”

A Multicenter Evaluation of Vancomycin-Associated Acute Kidney Injury in Hospitalized Patients with Acute Bacterial Skin and Skin Structure Infections

“…Antibiotics are administered for a pre-specified duration, generally 7-14 days, and in some RCTs there is the option to transition to oral therapy around day 3 [21][22][23][24]. In the realworld setting, patients have multiple risk factors, are frequently on concomitant nephrotoxic medications, and intravenous (IV) antibiotics are often continued long after patients became candidates for oral therapy [6,19,25,26]. This is concerning, because some studies have shown that the risk of V-AKI increases with longer durations of therapy [19].…”