Write a short note on status epilepticus and its management.

Definition

The operational definition has two time points that determine action:

• t1 — 5 minutes of continuous seizure activity (or two or more seizures without recovery of consciousness between them): the point at which treatment must begin, because self-termination is unlikely beyond this.
• t2 — 30 minutes: the point beyond which there is a risk of permanent neuronal injury.

Refractory status epilepticus — failure of an adequate benzodiazepine plus one second-line antiepileptic. Super-refractory — continuing or recurring 24 hours or more after starting anaesthesia.

Non-convulsive status epilepticus — altered consciousness or behaviour with electrographic seizure activity but no overt convulsion; it must be suspected in any patient who fails to wake after a seizure, and requires EEG to diagnose.

Pathophysiology

Prolonged seizures cause progressive internalisation of GABA-A receptors and mobilisation of NMDA receptors to the membrane — this is why benzodiazepines lose efficacy as the seizure continues, and why early treatment matters more than drug choice. Systemically, the first phase shows compensated hypertension, tachycardia and hyperglycaemia; after roughly 30 minutes compensation fails, giving hypotension, hypoglycaemia, hyperthermia, lactic acidosis, rhabdomyolysis, hyperkalaemia and cerebral oedema.

Causes

• In known epileptics (commonest): antiepileptic drug withdrawal or non-adherence — the single commonest precipitant — intercurrent infection, sleep deprivation, alcohol.
• Acute symptomatic: CNS infection (meningitis, encephalitis, cerebral malaria, neurocysticercosis — important in India), stroke, head injury, subarachnoid haemorrhage, tumour, hypoxic-ischaemic injury.
• Metabolic: hypoglycaemia, hyponatraemia, hypocalcaemia, hypomagnesaemia, uraemia, hepatic failure.
• Toxic: alcohol withdrawal, tricyclic antidepressants, tramadol, theophylline, isoniazid (responds specifically to pyridoxine), organophosphates, cocaine.
• Eclampsia in pregnancy — treated with magnesium sulphate, not conventional antiepileptics.

Management — a Timed Protocol

0–5 minutes — stabilise

• Airway (position, suction, oral airway, high-flow oxygen), breathing, circulation; secure intravenous access.
• CHECK CAPILLARY GLUCOSE IMMEDIATELY — give dextrose if low, with thiamine before glucose in alcoholics or the malnourished.
• Monitor ECG, blood pressure, saturation and temperature; protect from injury; note the time.
• Send bloods: glucose, electrolytes, calcium, magnesium, renal and liver function, CBC, antiepileptic drug levels, CK, arterial blood gas, and toxicology.

5–20 minutes — first-line: BENZODIAZEPINE

• Intravenous lorazepam is preferred (longer duration of anticonvulsant action than diazepam); intravenous diazepam or intramuscular midazolam where lorazepam is unavailable.
• If no intravenous access: intramuscular, buccal or intranasal midazolam — as effective as intravenous therapy in the pre-hospital setting and far quicker than establishing a line.
• A second dose may be given if seizures continue; do not give more than two doses, as further doses cause respiratory depression without added benefit.

20–40 minutes — second-line antiepileptic (intravenous loading)

Choose one and give a full loading dose: levetiracetam (well tolerated, few interactions, increasingly first choice), sodium valproate (avoid in women of childbearing potential and in hepatic disease), fosphenytoin or phenytoin (requires cardiac monitoring — risk of hypotension and arrhythmia; must not be given in dextrose, which precipitates it), or phenobarbitone.

40–60 minutes — refractory status: general anaesthesia

Transfer to intensive care; intubate and ventilate; induce anaesthesia with midazolam, propofol or thiopentone infusion, titrated with continuous EEG monitoring to seizure suppression or burst-suppression. Maintain for 24 hours, then wean while continuing maintenance antiepileptics. Support blood pressure with vasopressors as required.

Throughout — treat the cause and the complications

• Empirical antibiotics and aciclovir if CNS infection is suspected; imaging and lumbar puncture once the patient is stable.
• Pyridoxine for isoniazid-induced seizures; magnesium sulphate for eclampsia.
• Correct electrolytes, treat hyperthermia with active cooling, manage rhabdomyolysis with fluids, and give thromboprophylaxis.
• Continue maintenance antiepileptic therapy — controlling the seizure without starting maintenance guarantees recurrence.