The traditional treatment for refractory status epilepticus includes diazepam, midazolam, valproic acid, thiopental and propofol. These medications fail to control seizure activity in 20-40% of patients. This is attributed to decrease in activity of gamma-aminobutyric acid receptors along with reciprocal up regulation of N-Methyl-D-aspartate receptors. Glutamate activation of N-methyl-D-aspartate receptors promotes calcium influx and excitotoxicity. Ketamine, an intravenous anesthetic agent which is a non-competitive antagonist of N-methyl-D-aspartate receptors can block the flow of Ca and Na and by combining with phencyclidine binding sites inside the ion channel of N-methyl-D-aspartate receptors, reduce the epileptiform burst discharges and after potential. Therefore, targeting the N-methyl-D-aspartate receptors with ketamine may provide a novel approach to control refractory seizures. Moreover, by blocking glutamate mediated N-methyl-D-aspartate receptor induced neurotoxicity, ketamine may render neuroprotection. Ketamine also provides additional advantage of hemodynamic stability. Currently, ketamine is used as a last resort drug in the treatment of refractory status epilepticus.
The specific aim is to determine whether continuous infusion of ketamine as a first line agent for refractory status epilepticus is effective in controlling seizures.
The central hypothesis of our proposal is that early treatment with ketamine will be much more efficacious in controlling refractory status compared to the traditional treatment.
