Seizures

Objectives

To guide the management of patients presenting to medical facilities with suspected seizures, or status epilepticus.

Scope

This guideline covers the assessment and emergency management of patients with generalised tonic-clonic seizures and progression to status epilepticus. It does not cover partial seizure activity, or investigation and management of patients following a resolved seizure.

Audience

This guideline is intended for the use of registered healthcare professionals fulfilling a general role in forward medical locations or in an Emergency Department on deployed operations.

 

Background/Principles

Most generalised tonic-clonic seizures resolve spontaneously or following initial management. Status epilepticus is defined as a seizure that lasts for 5 minutes or more, or recurrent seizures without recovery in between. 

In a military context a patient who continues seizing despite initial management is likely to have a significant intracranial pathology or metabolic insult; ongoing supportive care following MARCH principles, and expediting evacuation, ideally with critical care support should be prioritised. 

This CGO is split into two sections at each stage of care, which should be considered concurrently. These are control the seizure and manage the cause.

Especially in the heightened stress of an operational environment, also consider the possibility of functional seizure in a patient who presents with prolonged shaking, especially if the presentation is atypical - see accordion content below. 

Initial Assessment & Management

Control the seizure

Patient presents with generalised tonic-clonic seizure activity.

Start a timer, or establish time from start of seizure activity

Perform primary survey, apply high flow oxygen, check blood sugar

Clarify history (if able) and consider causes that may be reversible. Consider the possibility of functional seizure, especially if the presentation is atypical (see accordion content below).

Establish IV/IO access if possible and prepare to administer first dose of benzodiazepine

If seizure already ongoing for ≥5 minutes, give first dose of benzodiazepine immediately. Otherwise wait until 5 minutes from seizure onset. Most seizures will self-terminate within 5 minutes.

At 5 minutes from seizure onset – confirmed status epilepticus (5 minute point)

Give lorazepam 4mg IV/IO or buccal midazolam 10mg, or alternative benzodiazepine as detailed in accordion content below.

Escalate: prioritise evacuation and request enhanced care support if not already available.

Prepare to administer second dose of benzodiazepine.

If seizure persists after 5 minutes following first benzodiazepine (10 minute point)

Give second dose of benzodiazepine.

Establish and secure IV/IO access if not already done

Communicate possible need for emergency anaesthesia

Prepare to administer second-line antiepileptic

If seizure persists after 5 minutes following second benzodiazepine (15 minute point) 

Give second line IV antiepileptic (levetiracetam 60mg/kg to a maximum of 4.5g given over 10 minutes)

Prepare to deliver emergency anaesthesia

If seizure persists after 5 minutes following completion of infusion (30 minute point) 

If appropriately skilled team available, deliver rapid sequence induction of anaesthesia

 

Manage the Cause

Although a new presentation of epilepsy ("first fit") is possible, in a military context a patient who experiences prolonged seizures despite initial management is likely to have a significant intracranial pathology or metabolic insult.

Particularly consider the following causes that may be reversible or amenable to treatment:

Head injury - aggressive seizure control is critical to reduce the risk of secondary injury. Escalate to enhanced care and aim to evacuate to a facility with CT imaging and neurosurgical capability without delay; give levetiracetam to all patients with post-traumatic seizure irrespective of duration of seizure. Patients with head injury and GCS <8 should also be given levetiracetam prophylactically as per head injury CGO 

Hypoxia - a systematic approach using MARCH principles will include airway management and ventilatory support that aims to correct hypoxia. Seek enhanced care support at an early stage.

Hypoglycaemia - correct without delay. See CGO.

CNS infection - if suspected then treat as per encephalitis / meningitis CGOs and consider the possibility of sepsis as per Immediate Management of Septic Patient CGO.

Heat illness - see CGO for Heat Illness

Toxins - seizures may result from exposure to a variety of medications, recreational drugs and environmental/industrial toxins; also consider the possibility of CBRN exposure depending on the operational context.

Alcohol Withdrawal - benzodiazepines are the most effective treatment and additional doses may be required if seizures recur; second-line anti-epileptics such as levetiracetam are unlikely to be of benefit, but should still be used as per the protocol outlined above if the underlying diagnosis is uncertain. 

Electrolyte imbalance - defining an electrolyte imbalance is unlikely to be possible in a forward location due to lack of access to testing, but consider precipitating causes - for example polydipsia that may have caused hyponatraemia. Consult individual CGOs for any suspected metabolic derangement.

Eclampsia - consider in any female of child-bearing age who presents with seizures; see below.

Advanced Assessment & Management

Control the seizure

Follow the protocol outlined above.

Induction of anaesthesia, if required, should follow standard protocols. Ketamine is accepted as an appropriate induction agent in status epilepticus.

 

Manage the Cause

As soon as point-of-care testing or laboratory facilities are available, all patients presenting with status epilepticus should have blood sent for:

  • Blood glucose and venous blood gas
  • Urea and electrolytes
  • Calcium
  • Magnesium and phosphate if available
  • Full blood count

Additional investigations may be required depending on suspected underlying causes - for example liver function tests and creatinine kinase for patients with suspected heat injury, or blood cultures (and possibly lumbar puncture) if there is any suspicion of an infective cause.

Patients in status epilepticus require early CT imaging so should be evacuated to a facility equipped to provide this as early as possible.

Prolonged Casualty Care

Most seizures resolve spontaneously within 5 minutes, and 60-90% of cases of status epilepticus resolve after administration of a benzodiazepine, so prolonged care of a casualty in status epilepticus is likely to be a rare event. Emergency evacuation is required, but if this is impossible then

  • Take care to ensure that all appropriate antiepileptic medication has been given as outlined above.
  • Use standard techniques to maintain airway, respiration and circulation; this can be challenging if fitting continues.
  • Titrate oxygen to likely length of patient hold
  • Carefully consider and treat underlying causes - cooling the heat illness patient or correcting the hypoglycaemia may resolve the seizure

Patients who recover following a seizure are likely to be initially very confused and may be agitated. Ensure the environment is a safe as possible to avoid injury to the patient and others - remove weapons, reassure and calm the patient, and if possible avoid loud or bright stimuli. Recovery will generally be over 10-20 minutes, but if the patient has a further seizure without full recovery then this represents status epilepticus - follow the protocol above.

If benzodiazepines have been administered, patients may be very drowsy; undertake a thorough assessment to ensure that other possible causes of a reduced level of consciousness have been excluded. Compromise is very unlikely if recommended benzodiazepine dose regimens have been followed, but should there be any concern then use standard approaches to maintain airway, respiration and circulation. Do not administer flumazenil.

In the event of prolonged hold of a patient who has required induction of anaesthesia, maintenance of sedation should ideally use propofol - aim to maintain deep sedation while ideally infusing <4mg/kg/hr. Levetiracetam should be continued at a maintenance dose of 1g IV every 12 hours, starting 12 hours after the loading dose.

Signs of ongoing seizure under general anaesthesia are often subtle and difficult to identify, but be alert to features such as persistent tachycardia, hypertension and rising end-tidal CO2. If these are seen then use a second-line anti-epileptic if available - either phenytoin (loading dose 20mg/kg to max 2g then maintenance 100mg IV TDS) or sodium valproate (loading dose 40mg/kg to max 3g then maintenance 1.2g IV BD).

Paediatric Considerations

Detailed guidance is available separately in the Paediatric Seizures CGO 

Benzodiazepine Options

As above, status epilepticus is defined as a prolonged seizure (>5 minutes) or multiple seizures occurring without full recovery of consciousness between.

The first-line treatment is to administer a benzodiazepine. The following options would be appropriate in adult patients:

Current drug of choice is lorazepam 4mg IV/IO. If not available then midazolam 5mg IV/IO or diazepam 10mg IV/IO are acceptable alternatives.

If IV/IO access cannot be established then midazolam 10mg bucally is recommended. Midazolam 10mg can also be administered IM but this requires high concentration midazolam to avoid an excessive volume for IM injection.

Rectal benzodiazepines are now rarely used, primarily because less effective than the options described above, but diazepam 20mg PR can be used if no IV/IO access and neither lorazepam nor midazolam available.

Eclampsia (Eclamptic Seizures)

Eclamptic seizures would be unusual in the first half of pregnancy but may be seen after 20 weeks' gestation and can occur post-partum (most often with 48 hours but reportedly up to 6 weeks).

If eclamptic seizures are suspected, the patient will require support from an enhanced pre-hospital care team and/or evacuation to a facility with resuscitation and critical care capabilities, as well as reach back for specialist advice if at all possible.

Treatment for eclamptic seizures is intravenous magnesium (4g as an infusion over 15 minutes) alongside standard management as described above. This should be administered if there is a known history of pre-eclampsia followed by seizures, or if the patient is visibly pregnant with the uterine fundus at or above the level of the umbilicus, with no other clear cause for seizures.

Otherwise, if seizures persist in a woman of child-bearing age despite benzodiazepines, check for pregnancy (urine sample, via catheter if needed, or ultrasound if appropriately skilled); if found to be pregnant then treat for eclampsia.

Functional Seizure

It is important to be aware of functional seizures as a potential cause for prolonged shaking activity. Functional seizures commonly present as apparent status epilepticus, and are a form of functional neurological disorder, without identifiable abnormal brain electrical activity. They commonly present as prolonged periods of shaking, collapses, or vacant episodes, almost always with a concurrent period of dissociation. Functional seizures are often associated with periods of increased stress, and therefore may be more common in a combat environment. 

Patients experiencing a functional seizure are generally aware of what is occurring, but are unable to respond. There is no method to absolutely differentiate between epileptic seizure activity and functional seizures by clinical assessment, but certain signs such as closed eyelids, resisting eyelid opening, a prolonged or fluctuating course, lacrimation, asynchronous limb movements, and side to side head shaking, are more suggestive of a functional seizure. Incontinence and tongue biting are not reliable differentiators. 

Initial treatment for the undifferentiated patient in apparent status epilepticus without a history of epilepsy or functional seizures should follow the seizure guidance above. If it is clinically likely that the patient is displaying functional seizure activity, then treatment involves withholding benzodiazepines, protecting them from injury, and reassurance.

Last reviewed: 05/07/2026

Next review date: 05/07/2027