4CPS-119 Predictive value of the arctic score and estimated glomerular filtration rate equations on levetiracetam plasma concentrations in critically ill neurotrauma patients

<h3>Background and Importance</h3> Achieving optimal drug exposure can be challenging in neurocritical patients with augmented renal clearance (ARC). <h3>Aim and Objectives</h3> To evaluate the accuracy of the Augmented Renal Clearance in Trauma Intensive Care (ARCTIC) score and different estimated glomerular filtration rate (eGFR) equations in predicting the variability of levetiracetam plasma trough concentrations (CpLEV) in critically ill patients. <h3>Material and Methods</h3> This observational study included patients admitted to a neurotrauma intensive care unit (NT-ICU) who received levetiracetam for post-traumatic seizure prophylaxis, with CpLEV assessed between October 2019 and May 2024. The eGFR was calculated using several equations [CKD-EPI, MDRD-6, and Cockcroft-Gault (C-G)]; and the ARCTIC score was used to predict ARC, with a cut-off value of ≥6. The therapeutic range of levetiracetam was defined as 10–40 µg/mL. Statistical analyses included ANOVA, Fisher-Snedecor F-distribution, and multivariate logistic regression (SPSS v25). <h3>Results</h3> A total of 46 patients were included (34 (74%) male): mean age 56 (range: 20–85) years; mean BMI 27 (range: 15–38) kg/m². Levetiracetam doses used were 500 mg/BID in 10 patients (22%), 1000 mg/BID in 28 patients (61%) and 1500 mg/BID in 8 patients (17%). The mean CpLEV was 18.7 (SD,15.8) µg/mL: 15 (33%) were subtherapeutic and 4 (8%) were supratherapeutic. The mean eGFR was 106 (SD:31), 135 (SD:65), and 114 (SD:50) mL/min/1.73m² using CKD-EPI, MDRD-6, and C-G, respectively. Several covariates were analysed (age, sex, BMI, route of administration, dose, eGFR), only dose and eGFR significantly influenced CpLEV (p&lt;0.001 and p&lt;0.002, respectively). CKD-EPI contributed to 26.3% of the variability in CpLEV, compared to 22.3% for MDRD-6 and 23.2% for C-G. The probability of subtherapeutic CpLEV was higher in patients with eGFR &gt;115 mL/min according to CKD-EPI [sensitivity: 83.3%; specificity: 62.5%], (p=0.002). Similarly, a higher likelihood of subtherapeutic CpLEV was observed in patients with an ARCTIC score ≥6 [sensitivity: 76.0%; specificity: 42.9%], although this was not statistically significant (p=0.174). <h3>Conclusion and Relevance</h3> CKD-EPI is the eGFR equation that most accurately explains the variability in CpLEV. A significant percentage of patients had subtherapeutic CpLEV values, which correlated well with an eGFR&gt;115 ml/min according to CKD-EPI. The clinical utility of ARCTIC score predicting subtherapeutic CpLEV remains limited, although it suggests a possible association. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest