Prolonged seizures, clusters and emergency treatment

Status Epilepticus & Rescue Medication

Status epilepticus is a neurological emergency in which seizure activity continues for too long, or seizures recur without adequate recovery between them. The practical emergency threshold depends on the seizure type, but for convulsive status epilepticus NICE uses 5 minutes: treatment should begin at that point rather than waiting for a seizure to continue for much longer.

Why 5 minutes matters

Older definitions of status epilepticus focused on seizures lasting 30 minutes or more. Modern emergency practice does not wait that long. NICE recommends resuscitation and immediate emergency treatment once a convulsive seizure reaches 5 minutes.

The reason is practical as well as biological: most ordinary tonic-clonic seizures stop before then, while a seizure that continues becomes less likely to stop spontaneously and more difficult to terminate. Longer convulsive seizures also increase the risk of low oxygen levels, aspiration, metabolic disturbance, injury and damage to other organs.

Status can happen with more than one seizure type

Status epilepticus is not limited to tonic-clonic seizures. It can occur with focal seizures, absence seizures, myoclonic seizures and other seizure types.

The 5-minute emergency rule specifically applies to convulsive status epilepticus. Non-convulsive status can look very different and may involve prolonged staring, reduced responsiveness, unusual behaviour, confusion, subtle movements or a prolonged change from the person’s normal state.

Because non-convulsive status may be difficult to recognise clinically, hospital assessment and EEG may be needed to confirm whether continuing seizure activity is present.

Repeated seizures without recovery

Status epilepticus can also mean a series of seizures occurring without the person adequately recovering between them. Someone does not have to be visibly convulsing continuously for the situation to be dangerous.

If another convulsive seizure begins before the person has recovered from the previous one, follow the emergency plan and seek urgent medical help.

Cluster seizures are related, but not identical

NICE describes repeated or cluster seizures as typically 3 or more self-terminating seizures within 24 hours and recommends managing them as a medical emergency.

A cluster does not necessarily mean one seizure has lasted continuously for 5 minutes. Each seizure may stop, but the unusually high number of seizures can still create risk and may progress to status epilepticus in some people.

If a person is known to have clusters, their individual plan may specify when rescue medication is given and when emergency services should be called.

A prolonged seizure can be abnormal even before 5 minutes

NICE also defines a prolonged convulsive seizure as one that continues for more than 2 minutes longer than that person’s usual seizure. This is important when someone’s normal seizures are very brief.

For example, if a person’s usual convulsive seizure lasts around 60 seconds, a seizure continuing several minutes beyond that may already represent a significant departure from their normal pattern even before the general 5-minute threshold is reached.

What is rescue medication?

Rescue medication is fast-acting medicine prescribed for a particular person to stop prolonged or repeated seizures before they progress further. In community epilepsy care, the main rescue medicines are benzodiazepines because they suppress excessive electrical activity quickly.

The two main community rescue treatments used in the UK are:

• buccal midazolam — placed into the buccal cavity between the cheek and gum
• rectal diazepam — administered rectally

Some children may be prescribed rectal paraldehyde in specific circumstances. Other medicines, including intravenous treatments, are used by healthcare professionals in hospital.

Buccal midazolam

Buccal midazolam is absorbed through the lining of the mouth and can act rapidly. Different products and strengths exist, including Buccolam and Epistatus.

These products are not automatically interchangeable. Epilepsy Society advises that the prescription should specify the product and strength because formulations and concentrations differ, and carers are trained to use the product prescribed for that person.

The dose is individual and may depend on age, weight and the prescribed product. Never guess a dose from another person’s medication.

Rectal diazepam

Rectal diazepam is another established rescue treatment. It can be effective but is less convenient and less dignified in many settings than buccal midazolam, which is one reason buccal treatment is commonly used in community care.

As with all rescue medication, it should be given according to the person’s written protocol by someone who has been appropriately trained.

An emergency plan matters as much as the medicine

A rescue-medicine prescription should be accompanied by an individualised emergency management plan. NICE recommends following that plan when it is immediately available.

A useful plan should state:

• what the person’s usual seizures look like
• how long they normally last
• the exact point at which rescue medication should be given
• the medicine, brand, dose and route
• who is trained and authorised to give it
• whether and when a second dose is permitted
• when to call emergency services
• what to monitor after the medicine is given
• what normal recovery looks like for that person

The plan should be reviewed when seizure patterns, medicines, weight, age or clinical circumstances change.

What if the first rescue dose does not work?

NICE says that if convulsive status epilepticus does not respond to the first benzodiazepine dose, emergency services should be called in the community.

Continue to follow the individual plan if it is available. If there is no plan directing otherwise, NICE recommends a second benzodiazepine dose if the seizure has not stopped within 5 to 10 minutes after the first dose.

This does not mean an untrained bystander should invent a second dose. The prescribed plan and training determine exactly what should be given and when.

What happens if two benzodiazepine doses fail?

Ongoing convulsive status after two benzodiazepine doses requires hospital-level second-line treatment. NICE lists intravenous levetiracetam, phenytoin or sodium valproate as options, with the choice made by clinicians according to the individual situation and current medicine-safety rules.

If second-line treatment fails, expert teams may use another second-line medicine, phenobarbital or general anaesthesia. These are hospital treatments and are not part of community first aid.

Rescue medication can affect breathing

Benzodiazepines can cause sedation and, rarely, clinically important breathing suppression. This is one reason the person should be monitored closely after rescue medication.

However, prolonged convulsive status itself can also impair breathing and oxygenation. The existence of a possible medicine side effect is not a reason to withhold prescribed rescue medication when the person’s emergency plan says it is needed.

What should be monitored after rescue medication?

Stay with the person and observe breathing, colour, responsiveness and recovery. Follow the person’s plan and emergency-service instructions.

Seek urgent help if breathing remains abnormal, the person becomes blue or grey, the seizure continues, another seizure begins without recovery, there is serious injury, or the person does not recover in the way expected for them.

Do not put ordinary tablets, food or drink into the mouth during a seizure

Buccal midazolam is specifically designed and prescribed for administration into the cheek. That is very different from trying to give ordinary tablets, food, water or another oral medicine to someone who is convulsing or not fully conscious.

Do not force the mouth open and do not put objects between the teeth. Follow the rescue-medicine training exactly.

Possible causes of status epilepticus

Status can occur as part of established epilepsy, but clinicians also look for a trigger or underlying cause. NICE specifically highlights:

• missed or stopped antiseizure medication
• low blood glucose
• eclampsia during pregnancy
• alcohol withdrawal

Other acute illnesses, brain injuries, infections, metabolic problems, stroke or drug toxicity may also provoke prolonged seizures depending on the situation.

Dissociative seizures can sometimes resemble convulsive status

NICE specifically reminds clinicians that non-epileptic or dissociative seizures can resemble convulsive status epilepticus. This distinction can be difficult in an emergency.

A bystander should not try to diagnose the cause from appearance alone. A prolonged first seizure, an event outside the person’s normal pattern or a potentially life-threatening presentation still needs appropriate emergency assessment.

Non-convulsive status needs medical assessment

Non-convulsive status may present as prolonged confusion, staring, reduced responsiveness or subtle repetitive movements rather than dramatic convulsions. It can be especially difficult to recognise in someone who is already confused after a seizure.

If a person remains unusually altered for far longer than their normal postictal period, has persistent episodes of reduced responsiveness, or there is concern that seizure activity may still be continuing, seek urgent medical advice. EEG is often central to diagnosis.

When to call emergency services

Call emergency services for a convulsive seizure lasting 5 minutes or more, repeated seizures without recovery, a seizure continuing well beyond the person’s usual duration, serious breathing problems, a seizure in water, major injury, a first known seizure, or whenever the person’s individual emergency plan says to call.

If prescribed rescue medication has been given and the seizure does not stop as expected, follow the plan and call emergency services.

Read When to Call Emergency Services →

Training matters

Family members, carers, school staff and care-home staff who may need to give rescue medication should receive appropriate training. Training covers not only how to administer the medicine, but also when to give it, what side effects to watch for and what to do if it fails.

Someone should not rely on written internet instructions as a substitute for person-specific training and a prescribed emergency plan.

After an episode of status or repeated seizures

NICE recommends agreeing an emergency management plan after convulsive status, repeated or cluster seizures, or prolonged seizures when there is concern that the problem may recur.

A review may also look for why the event happened: missed doses, medicine levels, infection, sleep deprivation, alcohol withdrawal, a change in epilepsy pattern or another acute cause.

Sources and guidance

NICE NG217 — Status epilepticus, repeated or cluster seizures, and prolonged seizures

NICE Evidence Review 9 — Antiseizure medication for status epilepticus

Epilepsy Society — Emergency medication

Epilepsy Action — Status epilepticus and rescue medicine

NHS — What to do if someone has a seizure

Medical note: Rescue medication is person-specific. The prescribed emergency plan and training take priority over general website information. Never use another person’s rescue medicine or improvise a dose.