ICU · neurocritical-care

Acute Status Epilepticus — Comprehensive Full Management Cascade

Also known as Status epilepticus · Convulsive status epilepticus · Generalised convulsive status epilepticus · Non-convulsive status epilepticus · Refractory status epilepticus · Super-refractory status epilepticus · ESETT trial · Established status epilepticus · Anaesthetic coma for seizures · Burst suppression · Autoimmune encephalitis status epilepticus · Propofol infusion syndrome

Status epilepticus (SE) is a continuous seizure lasting more than 5 minutes, or two or more seizures without full recovery of consciousness between them. The 5-minute operational threshold (ILAE/Trinka 2015) exists because beyond it the seizure becomes self-sustaining, GABA-A receptors are internalised and trafficked away from the synaptic membrane (causing pharmacoresistance to benzodiazepines), NMDA and AMPA receptors are recruited to the membrane (perpetuating excitation), and neuronal injury begins. Management is a time-critical PHASED cascade with four stages. EARLY SE (0-5 min): abort with a benzodiazepine — IV lorazepam 4 mg (0.1 mg/kg), or IM midazolam 10 mg when no IV access (RAMPART showed IM midazolam superior to IV lorazepam when IV access absent), or IV/rectal diazepam. ESTABLISHED SE (5-30 min): second-line non-sedating AED infusion — levetiracetam 60 mg/kg (max 4.5 g), fosphenytoin 20 mg PE/kg (max 1500 mg PE) OR phenytoin 20 mg/kg, valproate 40 mg/kg. The ESETT trial (Kapur 2019, NEJM) proved all three are EQUALLY EFFECTIVE for established SE (~half stopped seizing and remained so at 60 min); levetiracetam is now widely first-choice because of ease of administration, no cardiac monitoring requirement, and the fewest acute adverse events. REFRACTORY SE (30+ min / ongoing after second-line): induce anaesthesia — intubate and start a continuous anaesthetic infusion: midazolam, propofol, thiopental/pentobarbital, or ketamine, titrated to EEG burst-suppression or seizure-suppression with continuous EEG monitoring. SUPER-REFRACTORY SE (continues or recurs 24+ h despite anaesthetic, including relapse on weaning the anaesthetic — Shorvon 2011): escalate to immunotherapy (IVIG, plasma exchange, corticosteroids, rituximab/cyclophosphamide), ketogenic diet, epilepsy surgery, hypothermia, and repetitive transcranial magnetic stimulation. Airway management is central — RSI with THIOPENTAL (3-5 mg/kg) is the classic neurointensivist choice because it is simultaneously an induction agent AND an anticonvulsant (augments GABA, suppresses seizure foci). Continuous EEG (cEEG) is MANDATORY after control of convulsive SE and should run 24-48 h after the last seizure to exclude non-convulsive status epilepticus (NCSE), which persists in roughly half of patients who 'stop shaking' clinically. ICU complications dominate morbidity: hypotension from anaesthetics (especially thiopental/pentobarbital — Claassen 2002 found 77% hypotension with pentobarbital vs 34% with midazolam/propofol), ventilator-associated pneumonia from prolonged intubation, thrombocytopenia and hyperammonaemic encephalopathy from valproate, and propofol infusion syndrome (PRIS — lactataemia, rhabdomyolysis, hepatomegaly, cardiac failure, death; keep propofol <4 mg/kg/h and <48 h where possible). Autoimmune encephalitis (anti-NMDA receptor, anti-LG1, anti-GAD) is an increasingly recognised and treatable cause of refractory and super-refractory SE, especially in young patients with no prior epilepsy — suspect it, antibody-test, and treat empirically with IVIG/PLEX plus steroids and add rituximab/cyclophosphamide for NMDA. Mortality is 15-30% overall, rising to ~40% in refractory and ~50-60% in super-refractory SE.