Status Epilepticus

The most appropriate intervention in this man with refractory status epilepticus is IV pentobarbital to abort both clinical and electroencephalogic seizure activity. Pentobarbital is the most commonly used drug with adequate documentation of effectiveness. He has failed to respond to the generally recommended initial drug therapy in appropriate doses [ie, IV lorazepam 4 to 8 mg/kg; IV phenytoin 20 mg/kg (15 mg/Kg in the elderly) to be given no faster than 50 mg/min monitoring blood pressure and the electrocardiogram for QT widening (doses above 30 mg/kg may provoke seizures); and phenobarbital 20 mg/kg]. Increasing the dose of phenobarbital is an acceptable alternative to pentobarbital. Paralysis with pancuronium may obliterate the clinical seizure activity, but will not alter the brain’s seizure activity; it is the latter which causes long-term neurologic damage. Several recent reports enthusiastically support the use of IV midazolam because of a lower likelihood of hypotension and respiratory depression, but the number of adults with refractory status epilepticus that have been reported to date is not sufficient to consider altering the recommendations of a recent consensus report. Isoflurane as an inhalation anesthetic is another alternative.

Status epilepticus is defined as more than 30 minutes of (1) continuous seizure activity; or (2) two or more sequential seizures without full recovery of consciousness between seizures. The seizure may be: (1) convulsive, generalized, and tonic-clonic with postictal depression; (2) nonconvulsive, producing a continuous or fluctuating “epileptic twilight” state; or (3) repeated partial seizure manifesting as focal motor convulsions, sensory symptoms, or impairment of function such as aphasia without altered consciousness. The prognosis of status epilepticus is determined primarily by the underlying cause and the duration of the status. Precipitants of status include cerebrovascular disease, epilepsy, medication change, anoxia, ethanol (or other drugs), metabolic imbalances, fever/infection, trauma, tumor, or central nervous system infection (congenital and idiopathic). Status epilepticus occurs as the first seizure episode in the majority of patients. The overall mortality of status is estimated as less than 30% in adults and less than 8% in children.


The patient has been adequately loaded with phenytoin and needs another agent. Propofol is the best choice in this setting. It is an effective anticonvulsant, it has a short half-life, which allows clinical neurologic assessment, and it decreases ICP by decreasing cerebral metabolic activity. Divalproex (Depakote) is an alternative, but it would not have any direct effects on ICP. Phenobarbital will reduce ICP and control seizures but has a very long half-life and will not allow easy neurologic assessment. Atracurium should not be started. Patients with seizures should not be paralyzed because it eliminates the ability of the clinician to assess for ongoing seizures.




References

  • Working Group on Status Epilepticus. Treatment of convulsive status epilepticus. recommendations of the Epilepsy Foundation of America’s Working Group on Status Epilepticus. JAMA 1993; 270:854-859
    Yaffe K, Lowenstein DH. Prognostic factors of pentobarbital therapy for refractory generalized status epilepticus. Neurology 1993; 43(5):895-900
  • Rivera R, Segnini M, Baltodano A, et al. Midazolam in the treatment of status epilepticus in children. Crit Care Med 1993; 21:991-994
  • Oertel M et al. Effect of hyperventilation, blood pressure elevation and metabolic suppression therapy in controlling intracranial pressure after head injury. J Neurosurg 2002;97:1045-1053
  • Marik P et al. The management of status epilepticus. Chest 2004;126:582-591