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24 Cards in this Set
- Front
- Back
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what is status epilepticus?
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single unremitting seizure 5 to 30 minutes long or a frequent clinical seizures w/o interictal return to baseline
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what is refractory status epilepticus?
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ongoing seizures following first- and second-line drug therapy
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what are some of the more common predisposing factors to status epilepticus?
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- antiepileptic drug noncompliance or discontinuation
- withdrawal syndrome assoc. with stopping alcohol, barbiturates, baclofen, or benzo's - acute structural injury (eg. encephalitis, tumor, stroke, trauma, anoxia, subarachnoid hemorrhage) - remote or longstanding structural injury - metabolic abnormalities - use of or o/d with drugs that lower seizure threshold - chronic epilepsy |
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what metabolic disturbances can cause status epilepticus?
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hypoglycemia
hepatic encephalopathy uremia pyridoxine deficiency hyponatremia hypocalcemia hypomagnesemia |
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what is mortality rate for adults presenting with first status epilepticus?
how about for status after cerebral anoxia? |
20%
69% to 81% note: underlying etiology is most important factor |
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what does neuronal death look like in 30 to 60 minutes of continuous seizure activity? ie. name the hallmark finding.
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cortical laminar necrosis on brain MRI
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what are the 2 best tests to diagnose status epilepticus?
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neuro exam and EEG
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what are the 3 most common forms of status epilepticus?
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1. simple partial (focal motor seizures, focal sensory symptoms, or cognitive sx w/o LOC)
2. complex partial (same as #1, but with LOC) 3. generalized tonic-clonic (always assoc. with impaired consciousness) |
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what are the 4 main drugs used to treat status epilepticus?
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1. benzodiazepines
2. phenytoin (or fosphenytoin) 3. barbiturates 4. propofol |
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what is the first line tx for status epilepticus? how do they work?
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benzo's: diazepam, lorazepam, midazolam
increase Cl- conductance in CNS GABA(A) receptors and thus decrease neuronal excitability |
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which is the first choice benzo to treat status epilepticus?
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diazepam: hi lipid solubility and crosses BBB quickly; affects seizure activity in 10 to 20 sec.
lorazepam takes longer to work, but also stays longer |
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When comparing lorazepam vs. phenytoin vs. diazepam plus phenytoin vs. phenobarbital, which was most effective in terminating generalized convulsive status epilepticus w/in 20 min and keeping a seizure-free state for 60 min?
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lorazepam
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when do you use midazolam in status epilepticus?
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continuous infusion for refractory status w/ minimal cardio side-effects
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what is good about tx of status epilepticus with phenytoin? what should you watch for?
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prevents recurrence of status for a longer time
monitor cardiac variables to check for brady- or tachyarrhythmias |
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what is better about fosphenytoin vs. phenytoin?
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less local irritation at infusion site
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what are the most useful barbiturates in status?
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phenobarbital and pentobarbital
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how do barbiturates work?
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like benzo's, they bind to GABA(A) receptors, amplifying action of GABA by extending GABA-mediated Cl- channel openings; boosts hyperpolarization
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if phenobarbital is so great, why not use it as first-line tx?
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higher risk of hypoventilation and hypotension than benzo's or phenytoin
has a very long half-life (87 to 100 hrs) |
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when is pentobarbital used in status?
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when it's refractory status.
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vasopressors are often required when treating status w/ which drug?
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pentobarbital
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what is propofol? what are some problems with it?
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it's a hindered phenolic compound
hypotension and respiratory depression |
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why is the use of valproic acid limited in tx of status?
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FDA allows only slow infusion rates;
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what would initial therapy look like in status?
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1. give 0.02 to 0.03 mg/kg of lorazepam and wait a minute to check effect
2. if no effect, keep giving lorazepam up to 2mg/min 3. start another IV catheter and start giving phenytoin (or fosphenytoin) - this will help prevent recurrence 4. EEG monitoring is ideal |
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what are primary drugs for refractory status epilepticus?
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phenobarbital
pentobarbital midazolam propofol |
