Emergency Medicine is Hard

Status epilepticus is a neurologic emergency that is characterized by a single seizure >5 minutes in length or two or more seizures without recovery of consciousness between seizures.  As seizures surpass the 5-minute mark, dramatic changes occur at the cellular level. GABA (inhibitory) receptors are downregulated and Glutamine and NMDA (excitatory) receptors are upregulated resulting in a diminished seizure threshold. The blood brain barrier is also compromised and potassium and albumin, both of which have excitatory effects on the CNS, can diffuse into the CNS system. As a result, this hype excitatory state makes standard seizure therapies much less effective in seizure termination. 

First line therapies:

• IV Lorazepam (Ativan) – 2 to 4 mg IV – Slower onset (~3 min), longer duration (12-24 hours)
• IV Diazepam (Valium) – 5 to 10 mg IV – Faster onset (~2 min), shorter duration (15min – 1 hour)
• IM Midazolam (Versed) – 10 mg

While IV lorazepam is considered the initial agent of choice if an IV is available, both IV lorazepam and IV diazepam have equal efficacy in controlling status epilepticus. Of note, IM Midazolam has been shown to be as safe and effective as IV lorazepam in prehospital studies.  

Note: Do not under-dose the benzos. The GABA receptors that the benzos act on have been downregulated

Longer-acting anti-epileptics:

• Keppra / levetiracetam (preferred) – 60 mg/kg (Max dose: 4500mg)

Refractory Status Epilepticus:

If patient requires refractory medications you may have to consider preparing for intubation both for airway protection and because you are probably worried about snowing the patient. Another thing you have to strongly consider is that many of these medications tend to have hemodynamic effects – specifically, they will plummet the blood pressure. So don’t be afraid to have a vasopressor like norepinephrine on hand before you intubate. 

• Propofol –  2-5mg/kg, then infusion of 2-10mg/kg/hr 
• Midazolam – 0.2mg/kg, then infusion of 0.05-2mg/kg/hr 
• Ketamine – loading dose 0.5 to 3 mg/kg, followed by infusion of 0.3 to 4 mg/kg/hr
• Lacosamide IV – 400 mg IV loading dose over 15 min, then maintenance dose of 200 mg q12hrs PO/IV
• Phenobarbital IV – 15-20 mg/kg at 50-75 mg/min

Notes about drips for refractory status epilepticus:

Propofol drip (preferred)

Dose: 2-10 mg/kg/h and titrated up to effect. Once again, you may require a vasopressor to counteract the vasodilation induced by propofol. 

Midazolam drip – easily titratable, can be used instead if you find propofol is dropping the BP too much; however midazolam tends to accumulate in peripheral tissue resulting in longer recovery periods

Dose: 0.05-4mg/kg/h

Ketamine – an NMDA receptor antagonist that blocks the hyperexcitatory pathway; has demonstrated increased utilization, safety and likely benefit in terminating refractory status epilepticus

Dose: 0.5-4.5 mg/kg or an infusion of 5mg/kg/h

Phenobarbital drip – long half-life and slow clearance; poor recovery; only use if propofol and midazolam are not working

Dose: Up to 20mg/kg IV