Status Epilepticus

Diagnosis

  • Generally accepted as convulsion lasting > 30 min
  • But treat if >5 min or two convulsions without intervening full recovery of consciousness
  • In adults main causes are stroke, hypoxia, metabolic, alcohol
  • Prolactin not useful: rises in convulsions but normalises in status
  • Non-convulsive status: difficult to diagnose.
    • In coma, requires an EEG.
    • In non-coma, may present as confusion, personality change, psychosis, with no other evidence of ongoing seizure activity.
    • In non-coma, hippus (fluctuating pupil size, nystagmus, cyclical stereotypical motor manifestations) may be clues.
  • Emergency CT required in most cases

Treatment

  • Outlook for convulsive status is poor: 10-20% mortality overall, and perhaps up to 50% if requiring GA
  • General: oxygen, BP, fluids, glucose, thiamine
  • All drugs cause sedation, hypotension, resp depression - but status has greater incidence of complications
  • Diazepam
    • PR 10-20mg effective in preventing seizures becoming status
    • IV 10-20mg at 2mg/min effective in 60-80% of status
    • Elimination half-life is 30 hrs, but when given acutely rapidly distributes so effective half-life is 30 mins. Thus, 50% seizure recurrence within 2 hours
  • Lorazepam IV 4mg at 2mg/min - may be preferable due to longer redistribution half-life, thus reduced recurrence.
  • Midazolam - IM and buccal midazolam have been shown effective in children, but not adults.
  • Phenytoin
    • Bolus 15-20 mg/kg at 20-25 mg/min. Do not give in same line as other drugs, or with glucose solutions.
    • As adjunct to benzodiazepine
    • Cardiac monitoring required
    • Purple glove syndrome: blue-purple colour around IV site 2-12 hrs after administration, then oedema, sometimes necrosis, incidence 1.7%.
    • Fosphenytoin reduces risk of purple glove syndrome but probably wide use not justified.