Seizure, Febrile, Emergency Medicine

Basics

Description

- Occurs between 6 mo and 5 yr of age associated with fever: - No evidence of intracranial infection or other defined CNS primary cause - Average age of onset is 18 " 22 mo - Children with previous nonfebrile seizures excluded

- Occurs in normal children with a systemic viral illness - High-risk children: - History of febrile seizure in immediate family members - Delayed neurologic development - Males

- Subgroups: - Simple febrile seizures: - Brief, self-limited lasting <10 " 15 min, resolve spontaneously - Generalized without any focal features

- Fever - Seizure may occur concurrent with recognition of the febrile illness - Seizure - Generalized tonic " clonic seizure most common: - Tonic phase: - Muscular rigidity - Apnea and incontinence - Self-limited and last only a few minutes

- Other seizure types: - Staring with stiffness - Limpness - Jerking movements without prior stiffening

- Lumbar puncture: - Not routinely indicated - Indications 12 " 18 mo of age: - History or irritability, decreased feeding, lethargy - Consider if deficient in Haemophilus influenzae type b or Streptococcus pneumoniae immunizations - Physical signs of meningitis and/or history consistent with meningitis - Complex seizure - Prolonged postictal state - Prior antibiotics altering presentation - Abnormal mentation after postictal state

- Indications >18 mo old: - Signs/symptoms of CNS infection present - Electrolytes and bedside glucose in infants and children with vomiting or diarrhea

- Febrile delirium - Febrile shivering with pallor and perioral cyanosis - Breath-holding spell during febrile event - Acute life-threatening event - Other causes of seizure: - Afebrile seizure occurring during febrile event - Sudden discontinuance of anticonvulsants - Infection: - Meningitis/encephalitis - Acute gastroenteritis, often with dehydration

- Head trauma - Toxicologic: - Anticholinergics - Sympathomimetics - Other

- Hypoxia - Metabolic disease - Intracranial masses - CNS vascular lesions

Occurs between 6 mo and 5 yr of age associated with fever:No evidence of intracranial infection or other defined CNS primary causeAverage age of onset is 18 " 22 moChildren with previous nonfebrile seizures excluded
Most common pediatric convulsive disorder:Affects 2 " 4% of young children in US
Occurs in normal children with a systemic viral illness
High-risk children:History of febrile seizure in immediate family membersDelayed neurologic developmentMales
Subgroups:Simple febrile seizures:Brief, self-limited lasting <10 " 15 min, resolve spontaneouslyGeneralized without any focal featuresComplex febrile seizures:Duration >15 minFocal featuresMore than 1 seizure within a 24-hr period
Risk of recurrence:One-third of casesEarly age of onset, history of febrile or afebrile seizures in 1st-degree relatives, and temperature <40 °C during initial seizure increase the likelihood of recurrence
Risk of subsequent epilepsy:Greatest for those with prior abnormal neurologic development, a complex (>15 min) 1st febrile seizure, a focal seizure, or a family history of afebrile seizuresOnly slightly greater than the general population if 1st febrile seizure is simple and neurologic development normalNot affected by the use of prophylactic medications

Because this is usually self-limited, intervention must be individualized in relation to airway, breathing, and seizure management

Etiology

Common childhood infections:

Upper respiratory illnesses
Otitis media
Roseola
GI infections
Shigella gastroenteritis

Diagnosis

Signs and Symptoms

Fever
Seizure may occur concurrent with recognition of the febrile illness
Seizure
Generalized tonic " clonic seizure most common:Tonic phase:Muscular rigidityApnea and incontinenceSelf-limited and last only a few minutesOther seizure types:Staring with stiffnessLimpnessJerking movements without prior stiffening

History

Careful history and physical exam help confirm diagnosis and rule out other etiologies
Symptoms/evidence of infectious illness
Duration and pattern of fever
Medication exposure/toxin
Recent immunizations
Trauma/occult trauma
Growth pattern and developmental level
Family history of seizures
Complete description of seizure

Physical Exam

Reducing temperature may be useful in evaluation; give antipyretics early
Evidence of infectious illness-rash, ear infection, respiratory infection, diarrhea, etc.
Careful neurologic exam including mental status
Presence of meningismus, bulging fontanelle, nuchal rigidity, etc.
Evidence of focal deficit or increased ICP

Diagnosis Tests & Interpretation

Lab

Routine lab studies not indicated
Evaluate for a source of fever if serious bacterial infection is suspected:WBCUABlood and urine cultures
Lumbar puncture:Not routinely indicatedIndications 12 " 18 mo of age:History or irritability, decreased feeding, lethargyConsider if deficient in Haemophilus influenzae type b or Streptococcus pneumoniae immunizationsPhysical signs of meningitis and/or history consistent with meningitisComplex seizureProlonged postictal statePrior antibiotics altering presentationAbnormal mentation after postictal stateIndications >18 mo old:Signs/symptoms of CNS infection presentElectrolytes and bedside glucose in infants and children with vomiting or diarrhea
EEG:Not helpful in the initial evaluation of febrile seizuresMay be indicated if developmental delay, underlying neurologic abnormality, or focal seizureDoes not help predict recurrences or risk for later epilepsy
Anticonvulsant levels
Toxicology studies of blood and urine if history and physical exam suggestive

Imaging

Chest radiograph only in patients with significant respiratory symptoms or pertinent findings on physical exam
Head CT:Indicated with traumatic injuries, focal neurologic findings, or inability to exclude elevated intracranial pressure

Differential Diagnosis

Febrile delirium
Febrile shivering with pallor and perioral cyanosis
Breath-holding spell during febrile event
Acute life-threatening event
Other causes of seizure:Afebrile seizure occurring during febrile eventSudden discontinuance of anticonvulsantsInfection:Meningitis/encephalitisAcute gastroenteritis, often with dehydrationHead traumaToxicologic:AnticholinergicsSympathomimeticsOtherHypoxiaMetabolic diseaseIntracranial massesCNS vascular lesions

Treatment

Pre-Hospital

Protect the airway
Oxygen
Support breathing as needed
Cautions:Keep child from incurring injury while actively convulsingRespiratory insufficiency and apnea occur secondary to overaggressive treatment with benzodiazepinesSimple febrile seizures are self-limited and generally require no anticonvulsant therapy or ventilatory support

Initial Stabilization/Therapy

Support the airway and breathing
Benzodiazepines rarely needed:Prolonged seizures or compromised patientsLorazepam, diazepam, or midazolamRectal diazepam or nasal midazolam may be easily administered with good efficacy

Ed Treatment/Procedures

Rarely is pharmacologic intervention required; usually self-limited
Seizures refractory to benzodiazepines:Phenytoin or fosphenytoinPhenobarbitalWorkup to exclude other etiologies
Administer antipyretics acutely and routinely for at least the next 24 hr:Acetaminophen and/or ibuprofen (may use both)
Appropriate antibiotic treatment for specific bacterial disease if identified
Reassure and education of parents is essential

Medication

Acetaminophen: 10 " 15 mg/kg/dose PO, PR; do not exceed 5 doses/24 h
Diazepam: 0.2 mg/kg IV (max. 10 mg); 0.2 " 0.5 mg/kg PR (max. 20 mg)
Fosphenytoin: 20 mg/kg IV over 20 min
Ibuprofen: 10 mg/kg PO
Lorazepam: 0.1 mg/kg IV (max. 5 mg)
Midazolam: 0.05 " 0.1 mg/kg IV; 0.2 mg/kg buccal/IN/IM (max. 7.5 mg)
Phenobarbital: 15 " 20 mg/kg IV over 20 min or IM; monitor for respiratory depression
Phenytoin: 15 " 20 mg/kg IV over 30 " 45 min

Follow-Up

Disposition

Admission Criteria

Recurrent or prolonged seizures
Fever with source not appropriately treated as outpatient

Discharge Criteria

Simple febrile seizures:Normal neurologic examSource of fever is appropriately treated as outpatient
Reassurance to parents

Followup Recommendations

Schedule follow-up with primary care physician

Pearls and Pitfalls

Although aggressive treatment of fever with antipyretics is often recommended, there is no evidence that this reduces seizure recurrence
Oral diazepam during febrile illness may reduce risk of recurrence; prophylactic anticonvulsants with other anticonvulsants rarely indicated " such treatment is controversial and to be considered only after extensive discussion

Additional Reading

Barata I. Pediatric seizures. Crit Decisions Emerg Med. 2005;19(6):1 " 21.
Blumstein MD, Friedman MJ. Childhood seizures. Emerg Med Clin North Am. 2007;25:1061 " 1086.
Hirabayashi Y, Okumura A, Kondo T, et al. Efficacy of a diazepam suppository at preventing febrile seizure recurrence during a single febrile illness. Brain Dev. 2009;31:414 " 418.
Offringa M, Newton R. Prophylactic drug management for febrile seizures in children. Cochrane Database Syst Rev. 2012;4:CD003031.
Steering Committee on Quality Improvement and Management; Subcommittee on Febrile Seizures American Academy of Pediatrics. Febrile seizures: Clinical practice guideline for the long-term management of the child with simple febrile seizures. Pediatrics. 2008;121(6):1281 " 1286.
Strengell T, Uhari M, Tarkka R, et al. Antipyretic agents for preventing recurrences of febrile seizures: Randomized controlled trial. Arch Pediatr Adolesc Med. 2009;163(9):799 " 804.
Subcommittee on Febrile Seizures; American Academy of Pediatrics. Neurodiagnostic evaluation of the child with a simple febrile seizure. Pediatrics. 2011;127(2):389 " 394.

Codes

ICD9

780.31 Febrile convulsions (simple), unspecified
780.32 Complex febrile convulsions

ICD10

R56.0 Febrile convulsions
R56.00 Simple febrile convulsions
R56.01 Complex febrile convulsions

SNOMED

41497008 Febrile convulsion (finding)
433083002 Complex febrile seizure
432354000 Simple febrile seizure
307200007 Recurrent febrile convulsion (finding)