Seizures - status epilepticus in PICU

General points

• Most seizures stop spontaneously within 5 minutes. Treatment is indicated if a seizure lasts longer than 5 minutes in an otherwise healthy child. Treatment may be given earlier in any child with an acute brain injury.

• Status epilepticus is recurrent seizures without recovery of consciousness between attacks or continuous seizure activity lasting for more than 30 minutes.

• There is increasing evidence that earlier treatment is associated with less refractory status epilepticus and possibly better outcome.

Treatment

1. Give oxygen. Support ABC.

2. Measure blood glucose. Give 2 mL/kg 10% glucose if blood glucose <3mmol/L

3. Check FBC, ABG/VBG, electrolytes, Ca, Mg, urea, creatinine, LFT

4. Consider blood cultures, anticonvulsant levels, toxicology screen, metabolic screen, ammonia, insulin and cortisol levels if hypoglycaemic.

5. Consider ceftriaxone (or cefotaxime and amoxicillin in neonates), aciclovir and CT scan. Do not do an LP.

6. First line agents are either:

   1. Diazepam 0.25 mg/kg IV (max 10 mg)

   2. Midazolam 0.15 mg/kg IV (max 10 mg)

   3. If there is no venous access, options are intramuscular midazolam (0.2 mg/kg) or buccal or intranasal midazolam (0.5 mg/kg)

7. Second line agents are indicated if seizures are continuing 5 minutes after two doses of a first line agent:

   1. Phenytoin 20-30 mg/kg IV (max 1 gram) over 20-30 min OR

   2. Phenobarbitone 20-30 mg/kg IV over 10-15 min in neonates

   3. If there is no venous access, Paraldehyde (see below)

8. Third line agents, if seizures continue 10 minutes after second line agent:

   1. Phenobarbitone 20-30 mg/kg IV (max 1 gram) over 10-15 min

   2. Sodium valproate 40 mg/kg IV over 10 minutes. Contraindicated if hyperammonaemia, liver disease, thrombocytopaenia or possible metabolic disease

   3. Levetiracetam 40 mg/kg IV over 10 minutes. Consider if possible metabolic/liver disease.

9. For children in CED, PICU should be notified if still seizing after one third line agent or at any time if the airway is compromised. Children still seizing after a third line agent will usually need to be admitted to PICU.

10. If seizures persist 5 minutes after a third line anticonvulsant, then either administer a second third line agent or move to pharmacological coma induction.

11. Pharmacological coma

    1. Intubation and ventilation will very likely be required, along with arterial and central venous access. Respiratory depression, hypoxia and poor airway control are at least as dangerous as the seizures.

    2. Continuous EEG monitoring should be performed, ideally until at least 24 hours after infusions stopped. EEG goal is burst suppression.

    3. The preferred first agent is a midazolam infusion. Give 0.15 mg/kg bolus followed by 2 microgram/kg/min. If seizures persist, repeat the bolus and increase midazolam by 2 microgram/kg/min every 5 minutes to max 24 microgram/kg/min. If no seizures for 24 hours, reduce midazolam by 1 microgramg/kg/min every 15 minutes.

    4. Additional phenobarbitone doses of 10 mg/kg may be given to a maximum of 40-60 mg/kg.

    5. If seizures persist despite midazolam infusion, change to thiopentone infusion - bolus 2-4 mg/kg followed by infusion 2 mg/kg/hr. If seizures continue, give additional boluses of 2 mg/kg and increase infusion by 1 mg/kg/hr every 30 minutes to maximum 6 mg/kg/hr. Vasopressor support is very likely to be required. Monitor thiopentone levels.

    6. Additional anticonvulsants (e.g. sodium valproate, topiramate, levetiracetam) should be added prior to weaning infusions. Where appropriate ensure that "background" anticonvulsant levels are therapeutic.

12. Other agents

    1. Consider pyridoxine 100 mg IV for children < 18 months old with recurrent or refractory seizures. Pyridoxine dependent seizures should respond in 10-60 minutes.

    2. Paraldehyde

       1. Can be administered from plastic syringes if used quickly.

       2. Paraldehyde must not be used if the container has been opened as it decomposes. The administration of partly decomposed paraldehyde is dangerous as it may cause metabolic acidosis and be fatal.

       3. Starship has a pre-diluted formulation which is given PR 0.8 mL/kg (max 10 mL) every 2-4 hours as required. It may be further diluted 2-5 fold with saline (sodium chloride 0.9%) or olive oil. Recommended administration in 20 mL syringe attached to 10F feeding tube, inserted 10 cm rectally. Hold buttock cheeks together for 2-3 min (PR paraldehyde is a powerful GI stimulant).

    3. Clonazepam. Neonate 0.25 mg (if ventilated). Child 0.5 mg. Adult 1 mg. May be repeated.