Febrile seizure

Background

Criteria: Seizure + temp >38 in pt age 6 mo - 6 yr without previous afebrile seizure
Simple versus complex:
Simple
<15 min in duration
No focal features
Only a single episode in 24 hours
Complex
Any exception to above
Risk Factors
Family history (2-4x higher)
Infection (viral and bacterial)
Recent vaccinations
Recurrence
Risk of recurrence:
If first seizure occurs in age <1yr = 50%
If first seizure occurs in age 1-3yr = 25%
If first seizure occurs in age >3yr = 12%
Majority of recurrences occur within 1st year; almost all occur within 2 years
Risk factors for recurrence include:
Young age at onset
Family history of febrile seizures
Low-degree of fever in the ED
Brief duration between onset of fever and initial seizure
Complex febrile seizure does not increase risk of recurrent seizures

Consider trauma, toxidromes, infection/ petechiae
Glucose check
if sz >5 min tx with IM, IV, IN Versed
Consider trauma or toxic cause
Classifly as simple or comple
Search for devel delay, fam hx,
Physical exam should focus on source of fever
Routine lab tests other than blood glucose not needed unless searching for cause of fever (UA, CBC, CXR, etc)
Consider LP if:
Age <12 mo (AAP guidelines)
However, bacterial meningitis is rarely the diagnosis if it not clinically suspected
Seizure occurs after the second day of illness
Concern for CNS infection
Febrile status epilepticus
Pmd visit w/ in 48 hrs
Sz in ED
Focal sz
Abnormal neuro/ phys exam
Irritable, poor feeding
Complex features
Slow postictal clearance
Pretreated with abx (consider partially tx meningitis if already on abx)
CT if:
Persistently abnormal neuro exam (especially with focal features)
Signs/symptoms of increased ICP
Consider for presence of VP shunt
Routine EEG not indicated
Consider only if developmental delay or for focal symptoms

Treat if initial seizure persists >5 min or for subsequent seizures
Benzodiapazines
Lorazepam (0.05 - 0.1mg/kg)
If seizure persists try one additional dose (risk of resp. depression incr if >2 doses)
Effective duration of action is up to 4-6 hours
Midazolam (0.1-0.3mg/kg)
Diazepam
Compared to lorazepam, less effective and more respiratory depression
Fosphenytoin (15-20 mg/kg)
Treat if seizure persists despite benzo tx
Onset of action may take as long as 30 minutes
Can cause hypotension and dysrhythmias
Barbituates
Consider only if benzos and phenytoin have failed
May lead to respiratory depression, especially when preceded by a benzo
Valproic acid
Has been shown to be effective when benzos, phenytoin, and barbituates have failed
Can be used as 2nd or 3rd-line treatment
Propofol
Treat underlying infection

Home: Simple febrile seizure and patient back at baseline with follow up in 1-2 days
Admit: Complex febrile seizures, lethargy beyond postictal period, uncertain home situation

Adapted from Gausche, Mistry, Donaldson, Pani, UpToDate

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