Assessment of Empiric Vancomycin Regimen in the Neonatal Intensive Care Unit

Vancomycin is used to treat serious gram-positive infections in neonates. Currently, there is no consensus on the preferred empiric dosing regimen or target trough vancomycin levels for neonates. The current Fraser Health empiric dosing regimen, implemented in 2010, was designed to achieve target trough levels of 5 to 15 mg/L.

To determine the percentage of neonates receiving vancomycin in whom target trough levels of 5 to 15 mg/L were achieved, to identify the times to negative culture result and clinical resolution, and to determine the incidence of nephrotoxicity.

A chart review was completed for patients who had received vancomycin in the neonatal intensive care unit of either Surrey Memorial Hospital or Royal Columbian Hospital from June 2012 to May 2017 and for whom at least 1 interpretable vancomycin level was available.

A total of 87 vancomycin encounters (in 78 neonates) were identified in which the drug had been given according to the Fraser Health empiric dosing regimen. Target trough vancomycin level (5 to 15 mg/L) was achieved in 75% of these encounters. The mean times to negative culture result and clinical resolution were 5 and 6 days, respectively. There was no statistically significant correlation between vancomycin level and time to clinical resolution (rs = 0.366, p = 0.072). Among cases in which the trough vancomycin level exceeded 15 mg/L, the incidence of nephrotoxicity was 22% (4/18).

The current Fraser Health empiric dosing regimen for vancomycin achieved target trough levels of the drug for most neonates in this study. Targeting trough levels less than 15 mg/L when appropriate to the infection type may limit nephrotoxicity associated with vancomycin in neonates. Further studies are needed to evaluate the clinical significance of various vancomycin levels.