Background and importance Patients undergoing extracorporeal membrane oxygenation (ECMO) may present significant changes in antibiotics pharmacokinetics (PK).

Aim and objectives To describe the PK of vancomycin in ECMO patients and the achievement of a therapeutic pharmacokinetics/pharmacodynamics (PK/PD) target.

Material and methods Retrospective PK study in adult critically ill patients treated with vancomycin with therapeutic drug monitoring (TDM) and undergoing venovenous ECMO in a university hospital from July 2017 to October 2021.

TDM samples (steady state): before dose and 2 hours after the intravenous infusion (intermittent infusion) or at any time (continuous infusion). PK parameters and area under the curve in plasma (AUC24h) estimated by Bayesian software.

Data collected: demographics, clinical, microbiological and PK/PD parameters: AUC24h, minimum inhibitory concentration (MIC), clearance (Cl), elimination half-life (t1/2), volume of distribution (Vd) and dosage recommendation. Infratherapeutic, therapeutic or supratherapeutic PK/PD target defined: AUC/MIC <400, 400–600 and >600, respectively.

Results Ten episodes of treatment from 7 patients: median (range): 58.5(35–68) years, 6 (85.7%) men. Infection type: respiratory 8 (80%) and bacteraemia 2 (20%); directed treatment in 6 (60%); most frequent pathogens: Staphylococcus epidermidis 3 (50.0%) (MIC: 1, 2 and 2 mg/L), methicillin-resistant S.aureus (MSSA) 2 (33.3%) (MIC: 0.5 and 0.5 mg/dL) and S. haemolyticus 1 (16.7%) (MIC: 1 mg/L).

Conclusion and relevance A high interindividual variability in vancomycin PK and need for dose adjustments was observed in critically ill patients with ECMO, which highlights the need for close therapeutic monitoring.

ECMO and CRRT patients were more likely to have supratherapeutic plasma concentrations requiring dose reductions.

Conflict of interest No conflict of interest