Status epilepticus in children

Status epilepticus is a convulsive seizure that lasts in children for 30 minutes, or a series of seizures that follow one another with such frequency that the patient does not have time to regain consciousness in the intervals between them.

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Risk factors for status epilepticus in children

Acute processes:

• electrolyte disturbances, such as Na+, Ca2+, glucose;
• stroke, anoxic/hypoxic brain injury;
• CNS infections, such as meningitis, encephalitis;
• drug intoxication/overdose;
• sepsis;
• acute renal failure.

Chronic processes:

• history of epilepsy, poorly controlled treatment, or recent changes in anticonvulsant medications;
• brain tumor or other intracranial space-occupying lesions.

How does status epilepticus manifest itself in children?

Often, epileptic status in children is a signal of the onset of epilepsy, but it happens that convulsive seizures first occur at later stages of its development. In newborns, a seizure occurs with incomplete loss of consciousness and its preservation to external stimuli.

Generalized epileptic status may manifest itself in tonic-clonic, tonic, clonic, myoclonic seizures. In patients with epileptic status without seizures, the EEG records peak-wave stupor and slow waves reflecting the state of epileptic twilight of consciousness (small prolonged epilepsy). Partial epileptic status may be elementary, somatomotor, or dysphasic. Complex partial epileptic status (temporal lobe epilepsy or prolonged epileptic stupor) is characterized by persistent preservation of epileptic twilight of consciousness.

In generalized epileptic status, the main property of an epileptic seizure is impaired - the ability to self-terminate. The number of seizures in epileptic status can reach several dozen or hundreds per day. Respiratory disorders and hemodynamic insufficiency develop, cerebral metabolic disorders progress, and the comatose state deepens to the point of death.

How to recognize status epilepticus in children?

Epileptic status is diagnosed when the duration of a seizure exceeds threshold values: from 5-10 minutes to more than 1 hour. During the period of epileptic status, EEG changes reflect the phenomena of hypoxia and cerebral edema. After the relief of epileptic status in children, an increase in paroxysmal activity on the EEG is possible, which does not at all indicate a deterioration in the condition - during this period, the ability of neurons to generate electrical potentials is restored.

Emergency care for status epilepticus

It is not recommended to hold a child with an epileptic seizure tightly, as this may cause injury. The patient is placed on a flat surface, and a pillow or a rolled-up blanket is placed under the head. To prevent biting of the tongue, lips and cheeks, if possible, something soft should be placed between the teeth. It is also necessary to prevent the tongue from sinking back. The head is turned to the side and the body is placed in the Trendelenburg position.

If spontaneous breathing is maintained after repeated convulsions (and after intravenous administration of anticonvulsants), oxygen therapy with 50-100% humidified O ₂ is administered. In case of neurological respiratory depression, tracheal intubation and artificial ventilation are necessary. The contents of the oropharynx and respiratory tract are aspirated.

It is necessary to provide access to the vein and begin infusion therapy after stopping the seizures. Depending on the age, it is recommended to administer a 20% or 40% glucose solution. The volume of fluid administered in epileptic status should be specifically limited only in case of overload. The patient should periodically change his body position. Due to the delay in urine excretion, a permanent catheter is inserted into the bladder.

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Relief of status epilepticus

• Airways - breathing - circulation... 100% O2. Check blood sugar and treat hypoglycemia.
• Arrest seizures with intravenous lorazepam (0.1 mg/kg) or diazepam (0.1 mg/kg) as first-line therapy.
• If the seizures do not stop within 10 minutes, the second choice therapy would be:
  • phenytoin 15-17 mg/kg by slow intravenous infusion (rate <50 mg/min), or fosphenytoin 22.5 mg/kg (equivalent to 15 mg/kg phenytoin) at a rate of up to 225 mg/min (equivalent to 150 mg/min phenytoin).
• Intubate and ventilate to maintain PaO2 and PaCO2 in the normal range.
• Volume replacement therapy to maintain adequate systemic blood pressure and cerebral perfusion pressure.
• Inotropes may also be required, especially if general anesthesia is needed to control seizures.

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Further treatment of status epilepticus

Find and treat the cause of the seizures.

• history of epilepsy ± recent changes in antiepileptic drug therapy;
• cessation of alcohol consumption, drug overdose;
• CNS infections, intracranial pathology such as stroke, subarachnoid hemorrhage.

In refractory status epilepticus, if seizures cannot be controlled after 30 minutes of second-line therapy, initiate propofol anesthesia (under EEG control).

Ensure that levels of long-acting anticonvulsants are within the therapeutic range.

Consider third-line therapy: eg, phenobarbitone 20 mg/kg infusion (rate <50 mg/min).

Treatment of complications of status epilepticus - hyperthermia, rhabdomyolysis (screening for myoglobinuria and measurement of creatine kinase), cardiac arrhythmias, pulmonary aspiration and neurogenic pulmonary edema.

Anticonvulsant treatment of status epilepticus

Epileptic status in children should not be treated with drugs that are unknown to the attending physician. Currently, diazepam (seduxen, relanium) or midazolam are most often used. Phenytoin (diphenin) may be the drug of choice for epileptic seizures. If seizures continue, phenobarbital or sodium thiopental are used. Intravenous administration of magnesium sulfate is possible.

In case of an uncontrollable seizure or during long-term transportation, treatment of cerebral edema should be started: dexamethasone, mannitol, furosemide (lasix) are administered. In addition, a hyperventilation regimen is indicated; if necessary, inhalation anesthesia is administered using halothane (fluorothane). After the seizures have been eliminated, magnesium sulfate and acetazolamide (diacarb) are continued to be used for mild dehydration.

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Special considerations

• Refractory status epilepticus in children is treated with general anesthesia. It should be used in a specialized unit, with the possibility of continuous EEG monitoring to control the effectiveness of the treatment.
• Thiopental has been the drug of choice in the past, but the side effect profile of high doses severely limits its use now. Bolus 250 mg, then infusion 2-5 mg/kg/h.
• Propofol has potent anticonvulsant properties and is increasingly used to treat refractory status. It is started with a bolus of 1 mg/kg, administered over 5 minutes and repeated if seizure activity is not suppressed. The rate of maintenance infusion is selected in the range of 2-10 mg/kg, using the lowest rate sufficient to suppress epileptiform activity on the EEG.
• Fosphenytoin is a precursor of phenytoin - 1.5 mg fosphenytoin is equivalent to 1 mg phenytoin. Since fosphenytoin is water soluble, it can be administered as an intravenous infusion three times faster than phenytoin (up to 225 mg/min, equivalent to 150 mg/min phenytoin), with therapeutic concentrations achieved within 10 minutes. Doses are expressed in phenytoin equivalents (PE).