What is the best approach to manage seizures in this patient?

Management of Seizures

Immediately administer benzodiazepines as first-line treatment, followed by levetiracetam, valproate, or fosphenytoin as second-line agents if seizures persist after optimal benzodiazepine dosing. 1, 2, 3

Initial Stabilization

• Assess circulation, airway, and breathing (CAB) and provide airway protection interventions, high-flow oxygen, and check blood glucose level immediately 4, 2
• Establish IV access without delay 2
• Conduct rapid neurological examination to determine seizure type and severity 2
• Obtain stat glucose, electrolytes, complete blood count, and renal function, but do not delay treatment initiation for these results 2
• Evaluate for reversible causes including hypoglycemia, hyponatremia, hypoxia, drug toxicity, CNS infection, stroke, or hemorrhage 1, 5

First-Line Treatment: Benzodiazepines

Administer lorazepam 4 mg IV slowly at 2 mg/min for adults, which demonstrates 65% efficacy in terminating status epilepticus and provides longer duration of action compared to other benzodiazepines 2

• For convulsive status epilepticus: lorazepam 0.1 mg/kg (maximum 2 mg) IV, repeat after at least 1 minute (maximum 2 doses) 4
• For non-convulsive status epilepticus: lorazepam 0.05 mg/kg (maximum 1 mg) IV, repeat every 5 minutes (maximum 4 doses) 4
• Benzodiazepines should be given when seizure lasts longer than 5 minutes or for recurrent seizures without return to neurologic baseline 3

Second-Line Treatment for Refractory Seizures

If seizures persist after optimal benzodiazepine administration, immediately initiate one of the following agents (all have similar efficacy at approximately 45-47% for status epilepticus) 1:

Levetiracetam (Preferred for Safety Profile)

• Administer 30-50 mg/kg IV at 100 mg/min (maximum 2,500 mg for pediatrics, up to 4,000 mg for adults) 4, 1, 2
• Has the lowest rate of life-threatening hypotension (0.7%) compared to fosphenytoin (3.2%) and valproate (1.6%) 1
• Demonstrates 73% response rate in refractory status epilepticus and 47% cessation at 60 minutes 2
• Adverse effects limited to nausea, rash, and behavioral issues 4, 1
• Recent evidence suggests higher doses (750-1,000 mg bid maintenance) achieve target levels more reliably than traditional 500 mg bid dosing 6

Valproate (Alternative with Excellent Safety)

• Administer 20-30 mg/kg IV at rate of 40 mg/min (maximum dose varies by indication) 4, 1, 7
• Achieves 88% seizure control within 20 minutes and has 79% efficacy versus 25% with phenytoin as second-line agent 2
• Has 0% incidence of hypotension compared to phenytoin (12%) 1
• Monitor for dizziness, thrombocytopenia, liver toxicity, and hyperammonemia 4, 1
• Thrombocytopenia risk increases significantly at trough levels above 110 μg/mL (females) or 135 μg/mL (males) 7

Fosphenytoin (Alternative)

• Administer 18-20 PE/kg IV 4, 1
• Higher risk of hypotension and cardiac dysrhythmias compared to levetiracetam and valproate 4, 1
• Less favorable safety profile makes it a third choice among second-line agents 1

Third-Line Treatment for Continued Refractory Seizures

If seizures persist after second-line agents, transfer to ICU and add phenobarbital 4:

• Administer phenobarbital 10-20 mg/kg IV loading dose (maximum 1,000 mg) 4
• Monitor closely for respiratory depression and hypotension, which are common complications 4
• Consider propofol 2 mg/kg (may repeat in 3-5 minutes; maintenance 5 mg/kg/h) for intubated patients without hypotension 4
• Continuous EEG monitoring is indicated for refractory seizures 4

Maintenance Dosing After Seizure Control

After resolution of status epilepticus, continue maintenance therapy 4:

• Lorazepam 0.05 mg/kg (maximum 1 mg) IV every 8 hours for 3 doses 4
• Levetiracetam 30 mg/kg IV every 12 hours or increase prophylaxis dose by 10 mg/kg (maximum 1,500 mg) 4
• Phenobarbital 1-3 mg/kg IV every 12 hours if used 4

Special Considerations

Single Self-Limited Seizures

• Do not administer long-term anticonvulsants for single self-limiting seizure within 24 hours 2
• Monitor for recurrent seizure activity during routine vital sign checks 2
• Prophylactic anticonvulsants show no benefit and possible harm to neural recovery 2

Known Seizure Disorder Patients

• Insufficient evidence supports or refutes loading with antiseizure medication in ED for patients with known seizure disorder who have returned to baseline 1
• Consider individual risk factors and seizure history when making this decision 1

Elderly Patients

• Start with reduced doses due to decreased unbound clearance and greater sensitivity to somnolence 7
• Monitor closely for fluid and nutritional intake, dehydration, and excessive somnolence 7
• LEV IV at mean dosage of 1,643 mg/day (range 500-4,000 mg) achieved 78.6% seizure control in elderly patients with good tolerability 8

Critical Pitfalls to Avoid

• Do not delay benzodiazepine administration for diagnostic workup; treatment should begin immediately when seizure lasts >5 minutes 2, 3
• Phenytoin is ineffective for seizures secondary to alcohol withdrawal, theophylline toxicity, or isoniazid toxicity 5
• Avoid abrupt discontinuation of antiepileptic drugs in patients on chronic therapy due to risk of precipitating status epilepticus 4, 7
• Do not use fixed phenytoin doses without weight-based adjustment, as this leads to subtherapeutic levels 4
• Consider non-convulsive status epilepticus in any patient with confusion or coma of unclear cause and obtain EEG at earliest opportunity 4, 5