Status Epilepticus in Children
Status epilepticus is defined as continuous motor seizure activity
for more than 20 minutes or as repeated episodes without intercurrent awakening.
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It occurs in children with a history of seizures,
as well as in those previously thought to be neurologically normal. Although it
is not unusual for no cause to be found, the most common identifiable causes are
infections such as meningitis or encephalitis, metabolic abnormalities or toxins,
head trauma, and hypoxic and ischemic injury. Because seizure activity increases
both brain and skeletal muscle metabolism and oxygen consumption, status epilepticus
may place the child at risk for cellular hypoxia. During a seizure, airway obstruction
and ineffective chest wall and diaphragmatic excursion are so common that arterial
hypoxemia and hypercapnia are the rule.
Treatment begins with reestablishing an airway, administering
oxygen, and ensuring adequate ventilation. Specific treatment is aimed at stopping
the seizure activity by the administration of anticonvulsant drugs, preferably by
the intravenous route. Especially in a newborn, intravenous administration of metabolic
substrate, including glucose and calcium, is important specific as well as supportive
treatment. Commonly used anticonvulsants include lorazepam, phenobarbital, paraldehyde,
and phenytoin.
Lorazepam is a rapid and reliable drug for stopping seizures.
It is administered in small intravenous boluses of 0.1 mg/kg, or it can be given
rectally if intravenous access is unobtainable. Phenobarbital is also used, 5 to
10 mg/kg up to a total dose of 20 mg/kg. The main complication is respiratory depression,
which can occur with high levels. The respiratory depression is exaggerated when
phenobarbital is used in combination with lorazepam. Phenytoin can also be given
intravenously in doses of up to 20 mg/kg, but it should be administered slowly to
avoid cardiovascular depression. Paraldehyde may be given rectally in a dose of
0.3 mL/kg. Finally, sodium thiopental in an intravenous dose of 1 to 4 mg/kg stops
the most intractable seizures; however, apnea almost invariably occurs, and the risk
of vomiting and aspiration may be high. Once the seizures are under control, a cause
should be established, with care taken to maintain an adequate airway and ventilation.
