Introduction: Super-refractory status epilepticus (SRSE) is SE that persists for more than 24 hours despite continuous infusions of anesthetics such as midazolam or pentobarbital. Lidocaine has been utilized in the management of SE since 1950s. Lidocaine acts by several mechanisms to control seizures including sodium channel blockade, decreasing mitochondrial metabolism, neuronal oxygen demand, or potassium efflux. Experience with lidocaine therapy in the setting of SRSE is limited particularly to adult and neonatal population. We present successful use of lidocaine in SRSE in PICU. Description: We present 5 pediatric cases (4 females, 1 male) in whom lidocaine infusions were initiated after failure of midazolam and/or pentobarbital infusions to control seizures, with ages from 2 weeks to 6 years old. Patients were treated with benzodiazepines (bolus and/or infusion) (n=5), levetiracetam (n=5), pentobarbital (n=4), phenobarbital (n=5), fosphenytoin (n=3), lacosamide (n=1), topiramate (n=1), and corticotropin (n=1) prior to lidocaine infusion. Lidocaine was administered as bolus 1-2 mg/kg, followed by infusion ranging from 50-100 mcg/kg/min. The lidocaine infusion duration ranged from 30 minutes to 10 days. The lidocaine infusion was stopped due to complete resolution of seizures on EEG (n=3), supratherapeutic concentrations (n=1), and due to attending’s decision (n=1). In all but one patient (who received lidocaine for only 30 min), lidocaine resulted in resolution of seizures but recurred in some after dose reduction. No patient experienced any adverse effect of lidocaine infusion. Discussion: Lidocaine is a class Ib antiarrhythmic with the structure that results in sodium channel blockade via multiple methods which may impact patients in SRSE even when other sodium channel blockers are in use. Lidocaine demonstrates an efficacy like other agents such as levetiracetam and phenytoin with response rates ranging between 60-100% and is considered a 2nd line agent for neonatal seizures. The most common adverse events associated with therapy are bradycardia, and hypotension. Supratherapeutic concentrations over 8 mcg/mL may increase the risk for seizures. The presented cases suggest lidocaine infusion may be an alternative agent in the management of pediatric SRSE.
Deshpande et al. (Sun,) studied this question.