What It Is
Febrile seizures occur in young children and are triggered by fever. Risk runs from about 6 months to 5 years and peaks during the second year of life. They have little connection to cognitive function, so the prognosis for normal neurologic function is excellent.
Types
Epidemiologic studies divide febrile seizures into 3 groups.
Simple febrile seizure. Fever in a child aged 6 months to 5 years; a single generalized seizure lasting less than 15 minutes; the child is otherwise neurologically healthy with no abnormality on exam or developmental history; the fever is not caused by meningitis, encephalitis, or any other illness affecting the brain. It presents as a generalized clonic or generalized tonic-clonic seizure.
Complex febrile seizure. Same age, neurologic status, and fever picture as a simple febrile seizure, but the seizure is focal or prolonged (>15 min), or multiple seizures occur in close succession.
Symptomatic febrile seizure. Same age and fever as a simple febrile seizure, but the child has a preexisting neurologic abnormality or acute illness.
Pathophysiology
The pathophysiology is unknown, but there are working theories.
This is a unique form of epilepsy that occurs in early childhood only with a rise in temperature. Genetic predisposition clearly contributes. The rate of temperature rise as a cause is a popular theory but is unsupported by more recent laboratory and clinical studies. A neurotropism or CNS-invasive property of certain viruses (human herpesvirus-6 [HHV-6], influenza A) and a bacterial neurotoxin (Shigella dysenteriae) have been implicated, but the evidence is inconclusive.
Statistics and Incidence
Febrile seizures occur in about 2-5% of children aged 6 to 60 months (6 months to 5 years) (American Academy of Pediatrics). Among children who have them, about 70-75% have only simple febrile seizures, 20-25% have complex febrile seizures, and about 5% have symptomatic febrile seizures. Recurrence happens in roughly one-third of children who have had a previous simple febrile seizure. A child younger than 12 months at the first simple febrile seizure has a 50% probability of a second; after 12 months that drops to 30%. The rate of epilepsy by age 25 years is approximately 2.4%, about twice the risk in the general population. The literature does not support that simple febrile seizures lower intelligence or raise mortality. Males have a slightly but definite higher incidence.
Clinical Manifestations
Children with simple febrile seizures are neurologically and developmentally healthy before and after the event. They do not seize without a fever, and the seizure is generalized clonic or generalized tonic-clonic. Seizure activity does not run past 15 minutes, though a postictal period of sleepiness or confusion can extend beyond that.
Assessment and Diagnostic Findings
No specific studies are indicated for a simple febrile seizure. Focus on diagnosing the cause of the fever. Other labs are driven by the underlying illness: a child with severe diarrhea, for example, may need electrolytes.
Medical Management
On a risk/benefit basis, neither long-term nor intermittent anticonvulsant therapy is indicated for children who have had 1 or more simple febrile seizures. Continuous therapy with phenobarbital or valproate decreases subsequent febrile seizures.
Pharmacologic Therapy
Benzodiazepine. These act rapidly in acute seizures. Oral diazepam given with each febrile episode can cut the number of subsequent febrile seizures. Many practitioners prescribe rectal diazepam, particularly for patients who have had prolonged febrile seizures, to prevent future febrile status epilepticus.
Antipyretics. They do not prevent simple febrile seizures, but antipyretic therapy is still worthwhile for comfort.
Nursing Management
Assessment
Identify the underlying cause and triggering factors; managing the cause drives recovery. Monitor vital signs, especially the tympanic or rectal temperature, along with HR and BP. Assess age and weight, since extremes raise the risk of poor temperature control. Track I&O; fluid resuscitation may be needed to correct dehydration.
Nursing Diagnoses
- Hyperthermia related to antigens or microorganisms that cause inflammation.
- Imbalanced nutrition related to inability to meet the body's daily energy needs.
- Ineffective tissue perfusion related to failure to nourish tissues at the capillary level.
Planning and Goals
- Temperature decreases from 39°C to a normal range of 36.5°C to 37°C.
- Patient stays free of complications and maintains normal core temperature.
- Patient and family identify measures to promote nutrition and follow the treatment regimen.
- Patient weight is within normal values.
- Patient demonstrates lifestyle changes to improve circulation.
- The significant other verbalizes understanding of the condition.
Interventions
Assess the underlying condition and body temperature, and monitor and record vital signs. Apply cold compresses to bring temperature down, and teach the family how to do it. Dress the child in light clothing that absorbs sweat and releases heat. Promote rest to reduce metabolic and oxygen demand. Increase fluid intake to help lower temperature and prevent dehydration. Discuss eating habits and encourage an age-appropriate diet. To improve tissue perfusion, elevate the head of the bed at night for gravitational blood flow.
Evaluation
Goals are met when the temperature has decreased from 39°C to a normal range of 36.5°C to 37°C, the patient is free of complications with a normal core temperature, the patient and family have identified nutrition measures and follow the regimen, weight is within normal values, lifestyle changes to improve circulation are demonstrated, and the significant other verbalizes understanding of the condition.
Documentation
Document individual findings (factors affecting, interactions, nature of social exchanges, specifics of behavior), cultural and religious beliefs and expectations, the plan of care, the teaching plan, responses to interventions and teaching, and progress toward the desired outcome.
Frequently Asked Questions
What is a febrile seizure? A febrile seizure is a convulsion in a young child triggered by fever, with no underlying central nervous system infection or metabolic cause. It is the most common seizure disorder of childhood (American Academy of Pediatrics).
What age range is affected? Febrile seizures occur in children aged about 6 to 60 months and peak during the second year of life (American Academy of Pediatrics).
What is the difference between a simple and a complex febrile seizure? A simple febrile seizure is generalized, lasts under 15 minutes, and happens once in 24 hours in a neurologically healthy child. A complex febrile seizure is focal, prolonged (longer than 15 minutes), or recurs within 24 hours (AAFP).
Will my child have another seizure or develop epilepsy? About one-third of children have a recurrence, and the risk is roughly 50% when the first seizure happens before 12 months of age. Only about 1-2% of children with simple febrile seizures go on to develop epilepsy, versus about 0.5% of children who never had one (AAFP).
Should anticonvulsants be given to prevent recurrence? No. The AAP recommends against both continuous and intermittent anticonvulsant therapy for children with simple febrile seizures. Antipyretics improve comfort but do not prevent recurrence (American Academy of Pediatrics).
What workup does a simple febrile seizure need? For a neurologically healthy child with a simple febrile seizure, routine lumbar puncture, EEG, neuroimaging, and blood studies are not indicated. The evaluation focuses on finding the source of the fever (American Academy of Pediatrics).
What is the most important thing to teach parents? Stay calm, protect the child from injury, time the seizure, and do not put anything in the mouth. Most febrile seizures are brief and benign, but call for help if one lasts longer than 5 minutes or the child does not return to baseline.