136 - Analysis of Necessary Empiric Vancomycin Use in a Pediatric Hospital

Publication Number: 136.3992

Rebecca Kruc, Mayo Clinic Children's Center, Rochester, MN, United States; Laura Dinnes, Mayo Clinic, Rochester, MN, United States; Guyu Li, Mayo Clinic Children's Center, Rochester, MN, United States; James Gaensbauer, Mayo Clinic Alix School of Medicine, Rochester, MN, United States

Background: Judicious use of antibiotics is important for preserving resources, limiting adverse impacts, and preventing antimicrobial resistance. Previous pediatric research has demonstrated overuse of vancomycin, and thus efforts to optimize empiric vancomycin use in children with suspected infection are warranted.

Objective: To describe empiric vancomycin prescribing and characterize factors associated with necessary use at a quaternary children’s hospital.

Design/Methods: We reviewed all inpatient IV vancomycin usage for any indication from 6/1/2023-5/31/2024 from the electronic medical records. Descriptive and statistical analysis was completed using Stata, including a non-matched case control study with odds ratios calculated with exact 95% confidence intervals and p-values. Cases represented patients in whom there was a laboratory confirmed pathogenic bacteria with antibiotic susceptibility suggesting a requirement for vancomycin. Changes in creatinine or GFR outside the normal ranges within 48 hours of starting vancomycin was noted as a possible renal effect.

Results: During the study period, there were 487 new vancomycin starts in 344 unique patients. 93 (19%) had a primary indication of prophylaxis; 394 had an infectious indication. Of these, 95.9% had a bacterial culture collected, including 60.9% with more than one culture. Blood was the most common source (87.1% of encounters), then urine (30.7%), tracheal secretions (12.7%) and cerebrospinal fluid (5.3%). Blood culture was positive in 17.7% (59/293). In only 36/394 encounters (9.1%) did eventual culture results indicate a potential need for vancomycin. Among ICU patients, the rate of potential need for vancomycin was 12/185 (6.5%). Results of the case-control study are summarized in Table 1. In addition, 13/36 (36%) of controls had vancomycin levels obtained, of which 3 were below the therapeutic target and 5 underwent multiple measurements of trough vancomycin. 3/36 (8%) had elevations in creatinine or decreases in GFR.

Conclusion(s): In our patient population, 9% had eventual identification of infection that required vancomycin, indicating that it may be an important component of empiric treatment in some children, but unnecessary in the majority. Vancomycin usage was associated with potential for renal injury, and increased resource allocation, including phlebotomy and monitoring of drug levels. NICU admission, prior history of MRSA, and presence of a central line are factors that may make vancomycin more likely to be necessary whereas neutropenic fever was not associated with increased risk. These factors may allow for more nuanced clinical algorithms.

Table 1
Factors associated with microbiologically confirmed infection requiring vancomycin (cases) among 394 clinical encounters.