Seizures in Adults, Part 2

March 23, 2017

Seizures in Adults – Status Epilepticus

In Seizures in Adults, Part 1, we discussed the workup, treatment, and disposition of ED patients with unprovoked seizures, as well as the route of medication administration for ED patients with known seizures.

Although we frequently encounter patients with seizures in the emergency department, it is less common to encounter patients with status epilepticus, which is recurrent seizures without recovery of consciousness between them.  We will now focus on the optimal management of status epilepticus in the ED.

ACEP recently addressed which agents should be used to terminate ongoing seizure activity in adults.  The policy affirms that the first line treatment is optimal doses of benzodiazepines, and assumes this has been initiated but has failed to abort the seizure activity.

The Level A recommendation is pretty obvious, and we assume you are doing this already.

  • EPs should administer additional antiepileptic medication to patients with status epilepticus who have failed treatment with benzodiazepines.  
The Level B recommendation addresses the first line agents.
  • EPs may administer IV phenytoin, fosphenytoin, or valproate for refractory status epilepticus.
The level C recommendation addresses some additional agents that are becoming more commonly used, and supports their use despite a lack of scientific evidence, based upon common use and expert experience.
  • EPs may administer IV levetiracetam (Keppra), propofol, or barbiturates for refractory status epilepticus.
Similar to the previous discussion of first-time seizues, the policy stresses the importance of seeking treatable causes of status epilepticus, such as:
  • Hypoglycemia
  • Hyponatremia
  • Hypoxia
  • Drug toxicity
  • CNS infection

(Don’t forget INH overdose in the category of drug toxicity, which has a unique treatment, pyridoxine.)

Regarding your first line options following optimal dosing of benzodiazepines, IV valproate appears to be as effective as phenytoin, and has fewer adverse effects.

In terms of second line agents, levetiracetam has a low incidence of hypotension and respiratory depression, which are both drawbacks of propofol.  However, for intubated patients, propofol appears to be a very effective option.

Optimal Loading Of Antiepileptic Medication:

Finally, the ACEP policy on managing seizures in adults provides some guidance for optimal loading of antiepileptic medication, both for routine management and for status epilepticus.  You can refer to the actual policy for more detail, but here are some key points.

  • Carbamazepine:  8 mg/kg oral suspension is recommended as a single oral load, noting that oral tablets have slow and erratic absorption.
  • Lamotrigine (Lamictal): This medication is usually titrated up due to high incidence of serious rashes, so only load if the patient has been using continuously for > 6 months and has been off of it for less than 5 days.  The dose is 6.5 mg/kg single oral load.
  • Levetiracetam (Keppra):  1500 mg single oral or IV load.  Doses up to 30-50 mg/kg IV can be used for status epilepticus with a maximum rate of 100 mg/minute.
  • Phenytoin:  20 mg/kg oral load should be divided into maximum doses of 400 mg every 2 hours. 18 mg/kg is the suggested IV load with a maximum rate of 50 mg/min in adults.  IV is faster, but carries more side effects, and the evidence shows that there is no advantage of either route in terms of seizure recurrence.  For status, you may increase the dose to 30 mg/kg total.
  • Fosphenytoin:  18 PE (phenytoin equivalents) per kg total IV load at max rate of 150 PE/minute.  This can also be given IM.
  • Valproate:  20-30 mg/kg IV load at maximum rate of 10 mg/minute.  The rate can be increased to 40 mg/minute in status.

For status epilepticus, propofol can be given in 2 mg/kg boluses every 3-5 minutes as tolerated, with a maintenance infusion of 5 mg/kg/hr.  Phenobarbital is loaded at 10-20 mg/kg IV, with an additional 5-10 mg/kg given 10 minutes later as needed.  Beware of hypotension and respiratory depression with both of these medications.

To summarize, controlling ongoing seizures is essential.  Be sure you are searching for treatable causes of seizure activity, and address those promptly.  Initial treatment for status epilepticus is optimal doses of benzodiazepines.  If that isn’t successful, there are a variety of medications available, so pick one and treat aggressively with multiple medications until control is achieved.

It is educational to review the details in the policy.  Contact us if you have any questions.

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