Ketamine in adult super-refractory status epilepticus: Efficacy analysis on a prospective registry

Background: Status epilepticus (SE) persisting despite two anti-seizures medications (ASM) and anesthetics is labeled super refractory (SRSE), correlating with important morbidity and mortality. Its treatment relies on expert opinions. Due to its pharmacological properties, ketamine (KET) has received increasing attention, but data are essentially retrospective. Aims: To describe an unselected cohort of adults receiving KET for SRSE. Methods: Analysis of a prospective registry of consecutive SE episodes, identifying SRSE patients receiving ketamine (KET). Comparison with recent adult series including more than 10 patients. Results: Eleven patients received KET after a median of 4 days (range: 2-20); median dose was 5 mg/kg/h (range: 2.5-15). KET provided permanent SE control in three (27%). Previous series, using KET administration delays and doses similar to our cohort, report KET efficacy in 28-96% of cases. Conclusions: We found a lower SE control rate than existing literature, whose data are, however, often retrospective, potentially selecting patients with less severe SE forms or responding to KET. This might explain outcome differences, as KET administration modalities were comparable with our cohort. Since randomized controlled studies are lacking on this subject, the analysis of this prospective, unselected cohort, if confirmed, suggests a current overestimation of KET efficacy in SRSE.