Status epilepticus (convulsive)

G41.9

DESCRIPTION

ILAE 2015

Convulsive status epilepticus (SE) is characterised by abnormally prolonged seizures lasting more than 5 minutes. It is a medical emergency .

After 30 minutes of generalised tonic-clonic seizures, the brain begins to suffer from hypoxia, acidosis, and depletion of local energy stores, cerebral oedema and structural damage.

Complications include:

  • hyperpyrexia,
  • disturbances of blood glucose,
  • respiratory depression,
  • renal failure,
  • cerebral oedema,
  • acidosis,
  • blood pressure disturbances,
  • inappropriate antidiuretic hormone (ADH) secretion,
  • hypoxic ischaemic damage to brain, myocardium and muscles.

DIAGNOSTIC CRITERIA

Clinical

  • Convulsive seizure lasting 5 minutes or longer to be managed as status epilepticus
  • The causes of convulsive status epilepticus may be:
    • Cryptogenic
    • Symptomatic with a known cause:
      • Acute: secondary to an insult to the brain, e.g. encephalitis, hypoxic episode, trauma and complex febrile seizures; as a result of treatment non-adherence and changes in anticonvulsant therapy.
      • Remote: cerebral palsy, post-stroke.
      • Progressive: brain malignancy, neurodegenerative disease.
      • Epileptic syndromes.

GENERAL AND SUPPORTIVE MEASURES

  • Maintain an open airway.
  • Place patient on side.
  • Admit to high or intensive care, if possible.
  • If unconscious, consider catheterisation.
  • Monitor:
    • heart rate,
    • acid–base status,
    • respiratory rate,
    • blood gases,
    • blood pressure,
    • SaO₂,
    • electrolytes,
    • neurological status,
    • blood glucose,
    • fluid balance,
    • antiepileptic drug blood levels,
    • osmolality.
  • Look for a possible cause of the fever and treat appropriately.
  • Cardiovascular and/or respiratory support if the patient is unable to maintain blood gases and blood pressure within the normal physiological range.
  • Ventilate to maintain PₐCO₂ in the low normal range, i.e. 4.0–4.5 kPa.

Maintain SaO₂ ≥ 95%:

  • Oxygen, by facemask or nasal cannulae.
  • Measure antiepileptic drug blood levels if there are breakthrough seizures on medication, signs of toxicity, drug interactions or concerns about adherence.

MEDICINE TREATMENT

Status epilepticus

Follow ABCD approach.
See flow chart on next page for management of Status epilepticus.
For buccal midazolam and rectal diazepam, use the intravenous formulation.

For the purpose of rationalising the management of convulsive status epilepticus (SE), it helps to divide or classify it into different stages as below:

  • Early SE (5-20 minutes).
  • Established SE (20–30 minutes).
  • Refractory SE (beyond 30 minutes).

Intravenous fluid:

  • Dextrose 5% in sodium chloride 0.9%, IV.
    • Avoid over hydration. Keep fluid volume at maintenance.
    • Maintain normoglycaemia and electrolytes within the normal range.

Other biochemical disorders

Correct abnormalities, if present, e.g. glucose, calcium and sodium.

For fever related symptoms:

  • Paracetamol, suppositories, rectal, 6 hourly.
Weight Dose
6 - 11 kg 125 mg
12 - 17 kg 250 mg
18 - 24 kg 375 mg
25 - 30 kg 500 mg
31 - 37 kg 625 mg
38 - 45 kg 750 mg
46 - 50 kg 875 mg

Note: Suppositories should not be divided, as the amount of drug in each portion may not be consistent.

DRUG MANAGEMENT OF STATUS EPILEPTICUS

PHASE MANAGEMENT GOALS
EARLY
STATUS
0-5 minutes


EMERGENT
INITIAL AED
5 minutes 		Early stabilisation phase
- Immediate ABC
- Diagnose hypoglycaemia
- Establish IV access

If IV access:
Lorazepam, IV, 0.1 mg/kg

If no IV access:
- Lorazepam, IM, 0.1 mg/kg
OR
Diazepam, rectal, 0.5 mg/kg
OR,
Midazolam, buccal 0.5 mg/kg 		- Maintain
saturation, CPP
(cerebral
perfusion
pressure)
- Support
haemodynamic
status
ESTABLISHED
STATUS
5-30 minutes


Urgent Status
Control Therapy 		If still convulsing after
5-10 minutes
Repeat Lorazepam, IV, 0.1 mg/kg

And load
Phenytoin, IV, 18 mg/kg
(infused in sodium chloride 0.9%
over 20 minutes, not exceeding
1-3 mg/kg/min)
OR
Phenobarbitone, IV, 20mg/kg

If still convulsing after
15-20 minutes (use alternative
option to what was used above)
Phenytoin, IV, 18 mg/kg
OR
Phenobarbitone, IV, 20 mg/kg
Refer ICU 		- Stop seizure
- Attain serum
AED to control
SE
REFRACTORY
STATUS
30-60 minutes 		ICU
Consideration for:
- Midazolam infusion
- Endotracheal intubation
and thiopental infusion
Neuroprotection 		- Stop seizure
- Support
haemodynamic
status

Note:
Once intravenous access is attained, take blood for glucose, blood gas analysis, electrolytes, LFTs, FBC and antiepileptic drug levels if patient is a known epileptic.

Monitor carefully for drug related respiratory depression.

Intubation, ventilation and administration of thiopental sodium infusion should only be performed in a centre with trained anaesthetists and a paediatric intensive care unit.

Once convulsions are controlled, consider maintenance therapy.

Cerebral oedema

Treat when clinically proven.

Mannitol, IV, 250 mg/kg administered over 30–60 minutes.

  • Do not exceed two doses without consulting with a specialist.

OR

Under specialist supervision:

  • Sodium chloride 5%, IV, 2 mL/kg infused over 30 minutes.

Cerebral oedema with associated space occupying lesion

  • Dexamethasone, IV, 0.5 mg/kg 12 hourly.

REFERRAL

Caution:
Attempt to control seizures and stabilise the patient before referral.

  • Failure to control seizures within 30 minutes.
  • Where the primary cause is unknown, or if the primary cause itself requires referral.