6029 Evidence of sub-therapeutic vancomycin trough levels in children: results from a closed-loop audit in a Tertiary Centre

Objectives Vancomycin is a commonly used glycopeptide antibiotic to treat gram-positive bacterial infections in paediatric patients.1 Currently, empiric dosing regimens of 40- 60mg/kg daily in divided doses (higher than the BNFc recommended doses2 3 are used in a tertiary centre, to target therapeutic trough levels of 10–20 µg/mL, or 15–20 µg/mL in severe infections.1 There is limited evidence to inform and guide paediatric vancomycin dosing guidelines and regimens.1 2 The key aim of this study was to evaluate whether current empiric dosing regimens achieved therapeutic vancomycin trough levels in children receiving intravenous vancomycin at a tertiary centre. Methods Retrospective, fully anonymised data collection was completed, as part of a closed loop two-cycle audit, on all paediatric inpatients (aged between >30 days and Results A total of 57 patients were included. The demographics of the cohort were 5.6 years mean age, 42% female, 25-day mean length of stay, 2.3 mean co-morbidities. 94% had normal renal function. Mean CRP was 70. Sepsis was the most common indication. 75% had a blood culture taken, of which 12 were positive (11 vancomycin sensitive, 1 vancomycin resistant). Compliance to local trust dosing regimen was 80%. 22.6% of patients had a first trough level within therapeutic range, and 53.6% had a second trough level within therapeutic range after dose/frequency adjustments. The mean number of dosing/frequency adjustments required to reach therapeutic range was 1.2 adjustments. Conclusion This study highlights poor rates of achieving therapeutic vancomycin trough levels in children with normal renal function. Despite good compliance with local trust dosing regimens, which are higher than BNFc national guidance, only 22.6% achieved therapeutic trough levels initially, and 53.6% after dosing/frequency adjustments. Sub-therapeutic antibiotic levels can potentiate further antibiotic resistance,4 5 and our findings warrant urgent re-evaluation of current practices for intravenous vancomycin usage and dosing in children. References J Hoang, et al. Canadian Journal of Hospital Pharmacy 2014. C Nash, et al. Reports to the Neonatal and Paediatric Pharmacist Group January 2016. BMJ Group Pharmaceutical Press, British National Formulary for Children 2023. LM Weiner, et al. Infection Control & Hospital Epidemiology 2016. V Bakke, et al. Acta Anaesthesiologica Scandinavica 2017.