Intravenous Vancomycin Use During Emergency Department Observation for Methicillin-Resistant Staphylococcus aureus–Suspected Skin and Soft Tissue Infections

Skin and soft tissue infections (SSTIs) are common complaints for patients presenting to the emergency department (ED). ED Observation is increasingly used as an alternative pathway to decrease hospital admission burden, often involving the administration of antibiotics and repeat exams over 12 to 24 hours. Few studies have evaluated the treatment of suspected methicillin-resistant Staphylococcus aureus (MRSA) infections and ED Observation failure rate. Our objective is to assess if the administration of vancomycin for these patients is associated with higher rates of hospital admission

We performed a retrospective cohort study at a single academic center in the Northeastern United States between 6/2024 and 11/2025. Patients were included if they were treated for an SSTI and received antibiotics while in ED Observation. Patients were divided into those treated with vancomycin versus other antibiotics with MRSA coverage (trimethoprim/sulfamethoxazole, doxycycline, clindamycin). Patients without these antibiotic orders were excluded. We assessed admission rates from ED Observation, 72-hour return rate, and length of stay (LOS). Categorical patient characteristics were described using counts with proportions and compared across groups using chi-squared or Fisher’s exact tests, as appropriate. Continuous patient characteristics were described using medians with interquartile ranges (IQR) and compared across groups using Wilcoxon ranked sum. All analyses were performed using Stata 19.5 (College Station TX) and a p-value of <0.05 was chosen a priori to indicate statistical significance.

A total of 256 patients were placed in ED Observation for SSTI, with 74 (28.9%) receiving antibiotics for MRSA coverage, of which 30 (40.5% of the MRSA group) received vancomycin. There were no significant differences between the group demographics for age, gender and acuity (p>0.5). Of this cohort, 57% of the vancomycin group were admitted, compared to 16% from the non-Vancomycin group (p<0.001). There was no statistically significant difference in 72-hour return visits (p>0.99) or LOS (p=0.373).

For patients with MRSA-suspected SSTIs placed in ED observation, treatment with vancomycin was associated with a significantly higher rate of observation failure and subsequent hospital admission compared to those receiving non-vancomycin MRSA antibiotics.