Download Seizures

Seizures
LMH ER Rounds
March 22, 2016
Prepared by Shane Barclay
OBJECTIVES
Assessing the seizing patient in the ER
Treatment of seizures in the ER
Seizures Definitions
Seizure: manifestation of abnormal hyper excitable
discharges of cortical neurons.
Status epilepticus: greater than 5 minutes of seizure
activity or..
more than 2 discrete seizures with incomplete recovery
between events or..
continuing seizure after administration of anti-seizure
medication.
Epilepsy: the occurrence of at least 2 unprovoked
seizures more than 24 hours apart.
Causes of Seizures
1.
Epilepsy – may be first presentation
2.
Hypoxia
3.
Metabolic (hypoglycemia, uremic, hepatic..)
4.
Electrolyte (hypo/hypernatremia, hypercalcemia)
5.
Drug intoxication (anticonvulsants, antidepressants,
antipsychotics, opioids, …)
6.
Drug withdrawal (alcohol, benzodiazepines, …)
Causes of Seizures
7. Trauma (occur ~15% blunt severe traumatic brain injury)
8. CNS neoplasm
9. Stroke
10. Intracranial hemorrhage
11. CNS Infection
12. CNS dysfunction (Alzheimer's – incidence ~ 12%)
Differential Diagnosis
Eclampsia
Pseudo-seizures
Syncope
Acute Dystonic reactions
Rigors
Examination
Vitals – make sure to check temperature.
Tongue biting. Although not sensitive, is quite
specific for tonic-clonic seizures ~ 98%.
Urinary incontinence – low sensitivity and
specificity.
Neurological exam: check for lateralizing signs.
Examination
Lab: Overall low yield ie only abnormal in around 15%
of patients:
CBC, glucose, lytes, Ca, Mg, renal, LFT, cultures,
toxicology screen, ECG, preg test if female. Serum
antiepileptic med if on them.
LP, CT imaging and EEG should be done, but typically
in a tertiary care facility.
Overview of Treatment
First Goal is to restore normal neuronal function.
The second goal is to determine if the seizure is due
to some treatable systemic condition or some
intrinsic CNS dysfunction.
Treatment
ABCD
Secure the airway if necessary, especially in status
patients.
Even if seizure has stopped, always establish an IV
in case of a second seizure.
Medications
Most patients, unless in status epilepticus, will have stopped
seizing by the time they reach the emergency department.
In that case one can still consider a benzodiazepine as well
as a second line medication to prevent a second seizure.
Medications
However if seizing or if a recurrent seizure occurs:
If unable to establish IV:
Midazolam 10 mg IM (if > 40 Kg) or 5 mg (if < 40Kg),
or Midazolam 0.2 mg/kg intranasal or buccal or Diazepam
0.5 mg/kg rectally
If IV established:
Lorazepam 0.1 mg/kg, or midazolam 0.2 mg/kg or diazepam
0.2 mg/kg IV
Second Line Medication
Follow benzodiazepines with Phenytoin 20 mg/kg
IV at 50 mg/min max.
If allergic to Phenytoin may use Phenobarbital 20
mg/kg IV at 100 mg/min.
If patient known epileptic and on medications,
usually give ½ the loading dose of their medication.
“Third line” Medications
Valproic acid 20-40 mg/kg loading dose at 5 mg/kg/min.
Propofol 3-5 mg/kg then infusion at 30-100 mcg/kg/min.
Pharmacology of Benzodiazepines
Lorazepam has ~ 12 hours of anti-seizure property
Diazepam has only about 20 minutes.
Therefore if you use Diazepam, a second line antiepileptic
medication must be started soon after.
Studies have shown that IM Midazolam is actually faster at
terminating seizures than IV Diazepam.
Even though Midazolam has a serum half life of 2.5 hours, brain
levels remain at near peak concentrations for at least 4 hours.
Status Epilepticus
Status epilepticus: greater than 5 minutes of seizure
activity or more than 2 discrete seizures with incomplete
recovery between events or failure to stop seizure after
one med.
Neuronal damage starts to occur after 20-30 minutes of
seizure activity due to impaired cerebral perfusion and
reduced brain oxygen and glucose levels.
The longer the seizure activity, the more refractory to
treatment.
Status Epilepticus
First line treatment is benzodiazepines as discussed prior.
Consider intubating earlier than later.
The rationale for intubation is that using second and third
line anti-seizure medications usually take much longer
than 30 minutes to administer.
Status Epilepticus
The most reliable way to achieve seizure control under 30
minutes is a benzodiazepine, Propofol and ketamine.
Propofol is a powerful antiepileptic.
However the longer the seizure occurs, GABA receptors,
which Propofol acts on, decrease in number and the
seizure becomes less responsive to Propofol.
You may need vasopressors to counteract the hypotensive
effect of Propofol.
Status Epilepticus
Ketamine blocks NMDA receptors thus giving it antiepileptic and neuroprotective properties.
As the seizure continues, NMDA receptors increase
making ketamine at least theoretically more effective.
Ketamine may also help obviate some of the hypotensive
effects of Propofol.
As well always consider antibiotics, as a common cause of
status is infection.
Rapid Sequence Termination
of Status Epilepticus
Antiepileptic if possible – phenytoin, valproate
Disposition
Admission or discharge is often determined by the clinical
features and causes that were related to the seizure.
Patients who present with a generalized seizure with no
other worrisome history have been discharged home with
close follow-up for investigations etc.
Even with a normal EEG and normal CT scan, 1 and 4
year recurrence rates are 14% and 24%, respectively.
However, antiepileptic medications do not affect this
recurrence rate.
Questions?