Résumé
Beta-Lactam (BL) therapy in critically ill patients is associated with intra and interindividual variations due to pharmacokinetic alterations. These variations make it challenging to predict the appropriate dose, which can impact clinical outcomes. In this study, our goal was to identify factors associated with achieving target BL plasma concentrations in critically ill patients and describe real world data for Therapeutic Drug Monitoring (TDM) at the Nimes University Hospital.Methods: we conducted a retrospective single center study. We collected demographic, biological, clinical, and prognosis data from patients admitted to ICU and benefiting from BL TDM. Based on French TDM guidelines, the proportion of patients attaining the recommended plasma concentrations was evaluated. Univariate and multivariate analyses were then performed to identify the determinants of BL target attainment.Results: a total of 156 patients were included between January 1st, 2018, and March 4th, 2021. High dosing regimens of BL were used. At the first time of dosing, 53 out of 156 patients (34%) achieved target BL plasma concentrations, 78 patients (50%) were overdosed, and 25 patients (16%) were underdosed based on TDM guidelines. The multivariate analysis revealed that normal CKD-EPI estimated glomerular filtration rate (eGFR) (OR= 1.02; CI= [1.01; 1.03]; p< 0.0001) and normal total body weight (OR= 1.03; CI= [1.01; 1.04]; p= 0.0048) were associated with on-target BL plasma exposure. Conversely, factors such as Continuous Renal Replacement Therapy (CRRT) (OR= 0.28; CI= [0.09; 0.89]; p= 0.0318) and antimicrobial therapy with Meropenem (OR= 0.31; CI= [0.14; 0.69]; p= 0.0041) were identified as risk factors for overdosing. No factors were found to be associated with under-dosing. Co-prescription of aminoglycosides with BL was a good predictor of BL overdosing.Discussion/conclusion: our findings indicate that achieving target BL plasma concentrations remains challenging in critically ill patients. Although previous studies have focused on under-dosing, our study highlights the concern of over-dosing. The results demonstrate that it is possible to predict the risk of target attainment/non-attainment, enabling physicians to tailor prescriptions and move towards personalized medicine.