4CPS-161 Vancomycin pharmacokinetic monitoring in critically ill neonatal patients

Background and Importance Vancomycin is a bactericidal glycopeptide antibiotic with activity against aerobic and anaerobic gram-positive bacteria. Its use in neonatal critically ill patients is widespread, as it provides treatment for typical pathogens affecting this population, which presents an increased risk of infection. Dose in these patients is adjusted according to gestational weeks and pharmacokinetic monitoring is essential due to its potential nephrotoxicity. Aim and Objectives Assessing possible under-exposure to vancomycin in critically ill neonatal patients after dosing, as recommended by standard guidelines. Material and Methods A retrospective observational study in a tertiary hospital was conducted from March 2021 to June 2023. Critically ill patients who received vancomycin with Results During the study period, 79 pharmacokinetic determinations were performed in 34 patients, corresponding to 45 treatments with a median duration of 6 days (4, 14), of which 31 (68.9%) were empirical. Pathogens were isolated in 28 (62.2%) of the microbiological cultures, the main ones being: S.epidermidis 11 (28.2%), E.faecalis 4 (10.3%) and K.pneumoniae 4 (10.3%). Most frequent diagnoses were: catheter infection 17 (37.8%), sepsis 8 (17.8%) and necrotising enterocolitis 8 (17.8%). 48 (60.8%) PC were sub-therapeutic, 29 (36.7%) within range and 2 (2.5%) supratherapeutic. 13 (26%) of the out-of-range PC achieved the desired targets thanks to the pharmacokinetic recommendations. Finally, nephrotoxicity was observed in 9 (13.3%) patients. Conclusion and Relevance 48 (60.8%) critically ill neonates were under-treated and 9 (13.3%) had nephrotoxicity with the dosing regimens recommended by standard guidelines. It is therefore necessary to review the recommended dosing regimens in this group of patients to achieve therapeutic PC of vancomycin from the start of treatment guided by pharmacokinetic monitoring. References and/or Acknowledgements Conflict of Interest No conflict of interest.