Management of status epilepticus.
OBJECTIVE
To review the aetiology and treatment of status epilepticus and present a practical approach to its management.


METHODS
A review of studies reported from 1966 to 1998 and identified through a MEDLINE search of the English-language literature on metabolic and toxic seizures and status epilepticus.


RESULTS
Status epilepticus describes a condition of prolonged or repetitive seizures and is refractory if it lasts longer than 20-30 minutes despite therapy. It may cause primary cerebral injury due to prolonged uncontrolled neuronal discharge or secondary cerebral injury due to hypoxia and hypothermia. To minimise neural damage, resuscitation, correction of metabolic defects and termination of the seizures should be achieved rapidly (i.e. within 10 minutes). Initial treatment includes intravenous lorazepam (2-8 mg/70kg) or diazepam (5-20 mg/70kg) and phenytoin (1500 - 2000 mg/70 kg) which will control seizures in up to 70% of patients. If status epilepticus becomes resistant to the initial treatment, the patient should be managed in a monitored environment, as further therapy usually includes agents that may anaesthetise the patient. In an adult patient, 'second-line' drugs include intravenous phenobarbitone (100 -1000 mg), magnesium sulphate (10 - 15 mmol), midazolam (8-20 mg followed by an infusion at 4-30 mg/hour), propofol (50 - 150 mg followed by an infusion at 100 -500 mg/hour), thiopentone (200 - 500 mg followed by an infusion at 100 - 500 mg/hr), lignocaine (100 -150 mg followed by an infusion of 150-200 mg/h), ketamine (50 - 100 mg followed by 50 - 100 mg/h), or isoflurane (0.5 - 1.5%), added singly or in combination. If the patient requires paralysis to reduce the metabolic effects of a prolonged seizure then continuous electroencephalography is required.


CONCLUSIONS
Status epilepticus is a medical emergency requiring urgent termination of seizures and management of the initiating factors. Lorazepam or diazepam and phenytoin are recommended as 'first-line' therapy.
Durham
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Department of Critical Care Medicine, Flinders Medical Centre, Adelaide, South Australia.