Status epilepticus is defined as a continuous seizure lasting for at least 20-30 minutes, or two or more discrete seizures between which the patient does not regain consciousness.
- The cause of status is often withdrawal of drugs. A maintenance drug should be initiated early in the course of status and continued at an adequate dosage.
- Most morbidity and mortality occurs from inappropriate administration of repeated doses of benzodiazepines in a ward setting. If the patient does not respond to an adequate dose of lorazepam, loading with phenytoin should be initiated.
- Lorazepam is preferable to diazepam in the management of status epilepticus. Both drugs are equally rapidly acting and effective in controlling seizures, but lorazepam has a longer duration of anti-seizure action than diazepam (12-24 hours cf. 15-30 minutes).
- Remember hypoglycaemia.
- Loading doses of phenytoin are often inadequate. The following dose, although outside SPC recommendations, is often more effective: 20mg/kg (1.5g for a 75 kg man) should be given at a rate not exceeding 50mg/min with cardiac monitoring. As much as 30mg/kg may be needed in some patients.
- Intravenous phenytoin should still be administered even if the patient has been on oral phenytoin (non-compliance is likely).
- Chlormethiazole has significant potential for cardiac and respiratory toxicity, and accumulates in lipid tissue. It has no role to play in the management of status.