"improving intensive care in Scotland"

Neurological emergencies

Status Epilepticus (SE)

There are around 14,000 cases annually in UK with an overall mortality of 25%. It can be categorised as in table 3.

 

Categories of status epilepticus

Generalised convulsive

Generalised non-convulsive: absence

Partial convulsive

Partial non-convulsive: complex partial

Table 3. Categories of status epilepticus.

 

This section relates to generalised convulsive SE.

Generalised convulsive (tonic/clonic) SE is defined as continuous seizure activity > 30 mins or intermittent seizure activity > 30 mins without return to normal consciousness. It is probably safer to think 10-20 minutes for definition (published studies use shorter times).

Why is time in SE important ?

  • Increased risk of cerebral damage
  • Increased risk of systemic damage
  • It is harder to stop seizures the longer they have gone on

Causes of status epilepticus

Causes of status epilepticus

Established epilepsy

* Drug withdrawal
* Intercurrent illness
* Metabolic disturbance
* Progression of disease

Acute cerebral disturbance

* Infection
* Trauma
* Cerebrovascular disease
* C erebral tumour

Acute toxic/metabolic disturbance

 

Table 4. Causes of status epilepticus.

Pathophysiology

Normally described in two phases.

Phase 1

This is characterised by:

  • Recurrent seizures on EEG and tonic-clonic motor effects
  • Increased BP, HR and CBF
  • Airway obstruction; apnoea; hypoxia; hypercapnoea
  • Massive catecholamine release, tachycardia, arrhythmias, labile BP
  • Raised CMRO2 (cerebral metabolic rate for oxygen) and CBF
  • Loss of cerebral autoregulation

Phase 2

This is characterised by:

  • Periodic epileptiform discharges and non convulsive siezures
  • Compromised cerebral perfusion with increased ICP and hypotension in the presence of loss of cerebral autoregulation

Later effects and potential complications

  • Hypotension and reduced CBF
  • Hyperpyrexia, hyperglycaemia
  • Systemic and cerebral hypoxia
  • Neurogenic pulmonary oedema
  • Rhabdomyolysis, ARF, hyperkalaemia
  • Lactic acidosis
  • Hepatic necrosis
  • DIC

Management

Airway: assess, maintain, give oxygen
Breathing: assess and support
Circulation: assess, gain iv access, take blood for tests and give fluids
Drugs to abolish seizure activity

or the sequence might need to be

Drugs to abolish seizure activity along with
Airway: assess, maintain, give oxygen
Breathing: assess and support
Circulation: assess, gain iv access, take bloods and give fluids

It is difficult /impossible to secure ABC with ongoing seizure activity and abolition of seizure activity may be required to allow adequate ABC management.

 

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