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33 Cards in this Set

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status epilepticus: three phases

pseudostatus phase (described as aborted, imperfect, or incomplete); convulsive status; and stuporous status;


AKA impending, established, and subtle status epilepticus

research with animals shows that repetitive seizures

become self-sustaining and pharmacoresistant within 15–30 min and can lead to neuronal injury at about the same time

The duration of what is accepted as status epilepticus has been shrinking progressively

30 min (Epilepsy Foundation of America's Working Group on Status Epilepticus); 21 to 20 min, 22 to 10 min (Veterans Affairs Status Epilepticus Cooperation Study),and most recently, a length of 5 min was proposed

“impending status epilepticus”, defined as

continuous or intermittent seizures lasting more than 5 min, without full recovery of consciousness between seizures

threshold time defining impending status epilepticus

5 min of continuous seizures is the threshold defining impending status epilepticus, which corresponds with the 5 min operational definition of status epilepticus

mean duration of generalised convulsive seizures in adults

ranges from 62·2 s to 52·9 s for the behavioural symptoms, and averages 59·9 s for EEG changes


None of the seizures recorded lasted 2 min

Subtle status epilepticus

coined by Treiman to draw attention to the fact that, during prolonged status epilepticus, both the motor and EEG expression of seizures become less florid, yet prognostic and therapeutic implications still those of convulsive status epilepticus. This stage is similar to Clark and Prout's idea of stuporous status epilepticus

Partly treated status epilepticus

In more than 10% of patients treated for status epilepticus, clinical seizures stop or only show subtle symptoms, but electrographic seizures continue.

The main causes of status epilepticus

low concentrations of AED (34%), remote symptomatic causes (24%), CVA (22%), anoxia or hypoxia (∼10%), metabolic causes (∼10%), and alcohol and drug withdrawal (∼10%)

4 prognostic factors important in predicting outcome of status epilepticus:

cause, age, seizure duration, response to treatment.

partly explain the failure of GABAA inhibition and the progressive pharmacoresistance to benzodiazepines as self-sustaining status epilepticus proceeds.

Endocytosis of the GABAA receptors

NMDA receptors in SE

AMPA and NMDA receptor subunits move to the synaptic membrane where they form additional excitatory receptors

status epilepticus can occur from this poisoning

Patients who developed status epilepticus from domoic acid poisoning showed neuronal loss at autopsy,

The first goal of treatment, before giving anticonvulsants

maintain airway and blood pressure

Because cerebral blood flow has become pressure-dependent, cerebral metabolic needs remain high, and arterial blood pressure commonly falls late in the course, systolic pressure should be maintained

>120 mm Hg, and should not be allowed to fall below 90 mm Hg, even if this requires the use of vasopressors.

acceptable initial treatments of status epilepticus

Type-1 evidence shows that lorazepam alone, phenobarbital alone, or phenytoin combined with diazepam, are all effective, and therefore all three represent acceptable initial treatments of status epilepticus.

two reasons for initiate treatment with two drugs that have different mechanisms

First, the time-dependent loss of potency of benzodiazepines documented experimentally suggests that those drugs should not be used alone when status epilepticus is treated more than 30 min after seizure onset, because 30 min of seizures are sufficient to cause a substantial decrease in benzodiazepine potency. Hydantoins lose potency more slowly than benzodiazepines, and starting them early should improve therapeutic results. Second, status epilepticus is a heterogeneous disorder, and attacking two mechanisms of action might increase chances of success.

treatment of impending or established status epilepticus

start with 20 mg/kg of fosphenytoin or phenytoin, and if status epilepticus persists, give an additional 10 mg/kg.

history of drug intolerance (eg, allergy to phenytoin or benzodiazepine) then

replace by intravenous (IV) valproic acid 40–60 mg/kg or IV phenobarbital 20 mg/kg;

history of progressive (PME) or juvenile (JME) myoclonus epilepsy (phenytoin/fosphenytoin harmful in PME, ineffective in JME),

replace with IV valproic acid or IV phenobarbital;

tonic status epilepticus with Lennox-Gastaut syndrome (might be worsened by benzodiazepines)

replace with IV valproic acid or IV phenobarbital;

acute intermittent porphyria

avoid P450 inducers, replace by NG gabapentin (if possible) or by IV valproic acid;

focal status epilepticus without impairment of consciousness

IV treatment not indicated, load anticonvulsants orally or rectally.

treatment of refractory status epilepticus

IV valproic acid-start with 40 mg/kg and, if status epilepticus persists, give an additional 20 mg/kg.

Ketamine: rule out

increased intracranial pressure before administration.

fosphenytoin causes few side effects

(pain, phlebitis) at the injection site.The purple glove syndrome is only reported anecdotally for phenytoin

there is one situation when fosphenytoin achieves therapeutic concentrations faster than phenytoin

In patients receiving chronic phenytoin treatment (even if concentrations are slightly subtherapeutic), fosphenytoin displaces phenytoin from its albumin binding sites, rapidly raising the free phenytoin concentration, which is the key to the drug's therapeutic action.

Refractory status epilepticus defined as:

failure to stop seizure with adequate amounts of two IV drugs

contraindications to valproic acid

<2 years, severe liver disease, mitochondrial diseases, pancreatitis, pregnancy

General anaesthesia

midazolam, propofol, barbiturate ketamine

because ketamine can raise intracranial pressure

confirm absence of intracranial masses (by CT scan)

holy grail of status epilepticus

The stopping of seizures is the holy grail, but most people accept a burst suppression pattern.

when to stop anaesthesia in treatment of SE

stop once a day, and if seizures recur anaesthesia is resumed for another 24 h.