Question 22

College Answer

Diagnosis: status epilepticus as > 5 minutes generalised convulsive, non-convulsive, (no return of consciousness), simple partial [Definition 2 or more convulsions with no recovery in between, or continuous convulsion > 30 min (alternative more recently accepted definition is > 5 min)]

Support: Airway, Breathing, Circulation.

Control: using hierarchy of drugs: benzodiazepine (midazolam) + phenytoin loading, propofol, barbiturate (phenobarbitone loading, thiopentone infusion), isoflurane, others. EEG to confirm, avoid paralysis.

Restore: therapeutic prophylaxis drugs if appropriate - check levels. Consider add newer generation agent in difficult cases.

Look for and treat cause:

History of epilepsy, Anti-convulsant compliance, Check and correct biochemical disturbance eg Na

(appropriate speed), hypoglycaemia, low Ca++, severe azotemia.

Look for toxins (TCA, theophylline, amphetamine and other recreational drugs, salicylate, glycols, alcohols, hydrocarbons etc).

Diagnose infective, hypoxic, vascular, metabolic or structural (trauma, neoplasm), physical(hyperthermia) cause - CT, LP, MR, porphyrins.

Treat CNS viral and bacterial infection empirically until excluded. Eclampsia specific management including LSCS, Mg, BP control.

Don't forget factitious epilepsy - look for atypical features, check lactate, EEG, reflexes etc. Consider drug withdrawal.

Treat complications - aspiration, rhabdomyolysis, hyperthermia.

Discussion

Its another one of those.

• Attention to the ABCS, with management of life-threatening problems simultanous with a rapid focused examination and a brief history.
• An attempt to reverse the status epilepticus with a bolus dose of benzodiazepine may be undertaken while the above assessment takes place.
• Airway:
  • The need for airway support shoud be assessed
  • The patient will likely need to be intubated
  • This has the added benefit of exposing the patient to barbiturate anaesthetics, benzodiazepines or propofol
• Breathing/ventilation
  • Routine pursuit of normoxia and normocapnea;
  • Minute volume may need to be titrated up in view of increased metabolic CO₂production
• Circulatory support
  • Hypotension arsiing from the use of sedating medications may require vasopressors
• Supportive management
  • Nutrition, thromboprophylaxis and pressure area care need attention, as the patient may remain immobile for a prolonged period
• Specific investigations
  • A CT brain and an EEG to confirm status epilepticus (if it is non-convulsive)are all but mandatory
  • Drug screening of serology, urine and history should be undertaken, to exclude reversible causes (eg. intoxication or withdrawal)
• Specific management
  • Correction of the aetiology (eg. intoxication)
  • First line antiepileptics should be given (phenytoin )
  • If response is not achieved, second and third line agents may be deployed (levitiracetam, valproate, benzodiazepine infusion)
  • Barbiturate coma may be required with EEG monitoring of response

Related content would consist of the following chapters:

• Management of Status Epilepticus in ICU
• Non-convulsive status epilepticus
• Relationship of seizure duration and neurological outcome
• Extracranial consequences of status epilepticus
• Causes of status epilepticus
• Features that discriminate "true" seizures from pseudoseizures

Oh's Intensive Care manual:

 

Chapter 49   (pp. 549) Disorders  of  consciousness  by Balasubramanian  Venkatesh

 

Chapter   50   (pp. 560) Status  epilepticus  by Helen  I  Opdam

 

Brophy, Gretchen M., et al. "Guidelines for the evaluation and management of status epilepticus." Neurocritical care 17.1 (2012): 3-23.