Guidance

Recommendations

Recommendations

People have the right to be involved in discussions and make informed decisions about their care, as described in NICE's information on making decisions about your care.

Making decisions using NICE guidelines explains how we use words to show the strength (or certainty) of our recommendations, and has information about prescribing medicines (including off-label use), professional guidelines, standards and laws (including on consent and mental capacity), and safeguarding.

1.1 Assessment and diagnosis

NICE has also produced a visual summary of the recommendations on diagnosis.

Assessment and referral for diagnostic investigations

Initial assessment
1.1.1

Be aware that urgent investigation to confirm a diagnosis of subarachnoid haemorrhage facilitates early treatment to prevent rebleeding from a ruptured aneurysm and minimises disability and death.

1.1.2

When carrying out an initial assessment in a person who presents with unexplained acute severe headache:

  • have a high index of suspicion for subarachnoid haemorrhage

  • take a careful history to establish the rate of onset and time to peak intensity of the headache.

1.1.3

Bear in mind that:

  • A 'thunderclap' headache (a sudden severe headache, typically peaking in intensity within 1 to 5 minutes) is a red-flag symptom of subarachnoid haemorrhage.

  • Thunderclap headache is associated with other conditions or causes such as migraine, cough, coitus or exertion. Most people with a thunderclap headache do not have a subarachnoid haemorrhage, but this should not deter further investigation if subarachnoid haemorrhage is suspected.

  • People with subarachnoid haemorrhage can present with a range of non-specific symptoms and signs and are at greater risk of a diagnosis being missed. Other symptoms and signs of subarachnoid haemorrhage include, but are not limited to:

    • neck pain or stiffness

    • photophobia

    • nausea and vomiting

    • new symptoms or signs of altered brain function (such as reduced consciousness, seizure or focal neurological deficit)

    • limited or painful neck flexion on examination.

1.1.4

If a person with a possible subarachnoid haemorrhage finds it difficult to describe their symptoms, for example because of a learning disability, language problem or altered consciousness, ask anyone who witnessed the onset of symptoms for a description (without delaying referral).

1.1.5

Refer people with suspected subarachnoid haemorrhage seen outside of acute hospital settings to an emergency department immediately for further assessment.

1.1.6

Ensure that people with suspected subarachnoid haemorrhage seen in acute hospital settings such as emergency departments are reviewed urgently by a senior clinical decision-maker to assess the person and think about alternative diagnoses.

1.1.7

Refer the person for an urgent non-contrast CT head scan if review in secondary care by a senior clinical decision-maker confirms unexplained thunderclap headache, or other signs and symptoms that suggest subarachnoid haemorrhage. Be aware that the diagnostic accuracy of CT head scans is highest within 6 hours of symptom onset.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on assessment and referral for diagnostic investigations.

Full details of the evidence and the committee's discussion are in evidence review A: symptoms and signs and evidence review B: diagnostic accuracy of investigations.

Pain relief and neurological assessment

1.1.8

Ensure that people with a suspected or confirmed subarachnoid haemorrhage are given effective pain relief, including opioid analgesia if needed. Document administration of opioid analgesia in the person's healthcare record.

1.1.9

When conducting a neurological assessment, check the person's care record and if opioid analgesia has been given, take into account its sedating and pupillary effects.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on pain relief and neurological assessment.

Full details of the evidence and the committee's discussion are in evidence review D: medical management strategies.

Diagnosing a subarachnoid haemorrhage

1.1.10

Diagnose a subarachnoid haemorrhage if the non-contrast CT head scan shows blood in the subarachnoid space.

1.1.11

If a CT head scan done within 6 hours of symptom onset and reported and documented by a radiologist shows no evidence of a subarachnoid haemorrhage:

  • do not routinely offer a lumbar puncture

  • think about alternative diagnoses and discuss with a senior clinical decision-maker

  • seek advice from a specialist.

1.1.12

If a CT head scan done more than 6 hours after symptom onset shows no evidence of a subarachnoid haemorrhage, consider a lumbar puncture.

1.1.13

Allow at least 12 hours after symptom onset before doing a lumbar puncture to diagnose a subarachnoid haemorrhage.

1.1.14

Diagnose a subarachnoid haemorrhage if the lumbar puncture sample shows evidence of elevated bilirubin (xanthochromia) on spectrophotometry.

1.1.15

Think about alternative diagnoses if the lumbar puncture sample shows no evidence of elevated bilirubin (xanthochromia) on spectrophotometry.

Referral and transfer to a specialist neurosurgical centre
1.1.16

Urgently discuss with a specialist neurosurgical centre the need for transfer of care of a person with a diagnosis of subarachnoid haemorrhage to a specialist neurosurgical centre.

1.1.17

Do not use a subarachnoid haemorrhage severity score in isolation to determine the need for, or timing of, transfer of care to a specialist neurosurgical centre. Be aware that the risk of rebleeding is highest within 24 hours of the onset of symptoms.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on diagnosing a subarachnoid haemorrhage.

Full details of the evidence and the committee's discussion are in evidence review B: diagnostic accuracy of investigations and evidence review C: severity scoring systems.

Detecting an aneurysm

1.1.18

Offer CT angiography of the head without delay to people with a confirmed diagnosis of subarachnoid haemorrhage to identify the cause of the bleeding and to guide treatment.

1.1.19

Diagnose an aneurysmal subarachnoid haemorrhage if:

  • CT angiography of the head shows an intracranial arterial aneurysm and

  • the pattern of subarachnoid blood is compatible with aneurysm rupture.

1.1.20

Seek specialist opinion without delay from an interventional neuroradiologist and neurosurgeon if:

  • CT angiography of the head shows an intracranial arterial aneurysm and

  • the pattern of subarachnoid blood is not compatible with aneurysm rupture.

1.1.21

If CT angiography of the head does not identify the cause of the subarachnoid haemorrhage and an aneurysm is still suspected, consider digital subtraction angiography (DSA), or magnetic resonance angiography (MRA) if DSA is contraindicated.

1.1.22

Diagnose an aneurysmal subarachnoid haemorrhage if:

  • DSA or MRA shows an intracranial arterial aneurysm and

  • the pattern of subarachnoid blood is compatible with aneurysm rupture.

1.1.23

Think about other diagnoses if DSA or MRA does not show an intracranial arterial aneurysm.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on detecting an aneurysm.

Full details of the evidence and the committee's discussion are in evidence review K: diagnostic imaging strategies.

1.2 Managing a confirmed aneurysmal subarachnoid haemorrhage

Medical management

Nimodipine
1.2.1

Consider enteral nimodipine for people with a confirmed subarachnoid haemorrhage.

1.2.2

Only use intravenous nimodipine within a specialist setting and if enteral treatment is not suitable.

Reducing the risk of venous thromboembolism

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on medical management.

Full details of the evidence and the committee's discussion are in evidence review D: medical management strategies.

Managing the culprit aneurysm

1.2.4

An interventional neuroradiologist and a neurosurgeon should discuss the options for managing the culprit aneurysm, taking into account the person's clinical condition, the characteristics of the aneurysm, and the amount and location of subarachnoid blood. They should document a proposed treatment plan based on the following options:

  • endovascular coiling

  • neurosurgical clipping

  • no interventional procedure, with monitoring to check for clinical improvement and reassess the options for treatment.

1.2.5

Do not use a subarachnoid haemorrhage severity score in isolation to determine the suitability of any management option.

1.2.6

If interventional treatment to secure the aneurysm is an option, offer:

  • endovascular coiling or

  • neurosurgical clipping if endovascular coiling is not suitable.

1.2.7

Discuss the proposed treatment plan and any alternative options with the person, and their family or carers if appropriate, then agree and document a final treatment plan (see recommendations 1.5.5 to 1.5.7).

1.2.8

If interventional treatment is planned, ensure that it is carried out at the earliest opportunity to prevent rebleeding. Be aware that the risk of rebleeding is highest within 24 hours of the onset of symptoms.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on managing the culprit aneurysm.

Full details of the evidence and the committee's discussion are in evidence review L: interventions to prevent rebleeding, evidence review C: severity scoring systems and evidence review M: timing of interventions to prevent rebleeding.

1.3 Monitoring and managing complications

Monitoring and investigating for deterioration

Transcranial doppler monitoring for deterioration
1.3.1

Do not use transcranial doppler monitoring to guide clinical management of an aneurysmal subarachnoid haemorrhage except in the context of clinical research.

Unexplained neurological deterioration
1.3.2

For people with unexplained neurological deterioration after a subarachnoid haemorrhage, offer a non-contrast CT head scan as the first diagnostic investigation to determine the cause.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on monitoring and investigating for deterioration.

Full details of the evidence and the committee's discussion are in evidence review E: monitoring for raised intracranial pressure and vasospasm.

Hydrocephalus

1.3.3

Base a diagnosis of acute or chronic hydrocephalus on the person's symptoms and signs, and on a comparison of current and previous CT or other brain imaging.

Acute hydrocephalus
1.3.4

Consider drainage or diversion of cerebrospinal fluid for people with neurological deterioration caused by acute hydrocephalus.

Chronic hydrocephalus
1.3.5

For people with persistent or progressive symptoms and a clinical diagnosis of chronic hydrocephalus, consider drainage or permanent diversion of cerebrospinal fluid. If there is uncertainty about the likely benefit of permanent diversion, consider a trial of temporary drainage to assess the need for permanent diversion.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on hydrocephalus.

Full details of the evidence and the committee's discussion are in evidence review G: detecting hydrocephalus and evidence review H: managing hydrocephalus.

Delayed cerebral ischaemia

1.3.6

Ensure euvolaemia (normal blood volume) in people with delayed cerebral ischaemia after an aneurysmal subarachnoid haemorrhage and consider treatment with a vasopressor if symptoms persist. Bear in mind that clinical improvement from vasopressor treatment may be temporary.

For a short explanation of why the committee made this recommendation and how it might affect practice, see the rationale and impact section on delayed cerebral ischaemia.

Full details of the evidence and the committee's discussion are in evidence review F: management of delayed cerebral ischaemia.

1.4 Follow-up care

Follow-up care plan

1.4.1

Agree and document a plan for follow-up care with the person after their aneurysmal subarachnoid haemorrhage. Give a paper copy of the plan to the person (and their family or carers if appropriate) and include details of who to contact at the specialist centre for ongoing advice and support.

1.4.2

Include the follow-up care plan in the person's medical record and discharge correspondence.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on follow-up care plan.

Full details of the evidence and the committee's discussion are in evidence review S: patient information.

Rehabilitation

Follow-up neuroimaging

1.4.4

Consider follow-up neuroimaging for people who have had an aneurysmal subarachnoid haemorrhage, taking into account the extent of their recovery and the suitability of further imaging. Base the choice of imaging modality, and the frequency and duration of imaging follow-up, on the:

  • type and outcome of any neurointervention or neurosurgery on the initial aneurysm

  • presence of any non-culprit aneurysms

  • estimated risk of further bleeding

  • risks of planned investigations and any subsequent interventions

  • person's preference.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on follow-up neuroimaging.

Full details of the evidence and the committee's discussion are in evidence review O: imaging strategies for follow-up.

Managing non-culprit (unruptured) aneurysms

1.4.5

A multidisciplinary team (MDT) that includes an interventional neuroradiologist and a neurosurgeon should evaluate the options for managing non-culprit (unruptured) aneurysms, including:

  • endovascular coiling

  • neurosurgical clipping

  • conservative management and follow-up monitoring.

1.4.6

When evaluating the options for managing a non-culprit aneurysm, the MDT should take into account:

  • the size and location of the aneurysm

  • the estimated lifetime risk of the aneurysm rupturing

  • the estimated risk of each treatment option

  • any comorbidities

  • the person's preferences.

1.4.7

Discuss the proposed management plan and any alternative options with the person (and their family or carers as appropriate). Base the discussion on the factors listed in recommendation 1.4.6. Agree and document a final management plan.

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on managing non-culprit (unruptured) aneurysms.

Full details of the evidence and the committee's discussion are in evidence review P: non-culprit aneurysms.

Managing other conditions after discharge from hospital

Hypertension
Conditions treated with an antiplatelet or anticoagulant
1.4.9

Do not withhold treatment with antiplatelets or anticoagulants solely on the basis of an aneurysmal subarachnoid haemorrhage if the culprit aneurysm has been secured by coiling or clipping.

1.4.10

Balance the risks and benefits of treatment with an antiplatelet or anticoagulant, taking into account specialist assessment of the risk of a future subarachnoid haemorrhage.

Smoking
Headaches
1.4.13

Be aware that headaches in people with a history of aneurysmal subarachnoid haemorrhage:

  • are common and generally benign

  • may be due to chronic hydrocephalus if the person has additional symptoms or signs such as gait disturbance, incontinence, incoordination or cognitive impairment.

Seizures

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on managing other conditions after discharge from hospital.

Full details of the evidence and the committee's discussion are in evidence review Q: long-term medicines for reducing the risk of subsequent subarachnoid haemorrhage and evidence review R: long-term medication for managing the consequences of subarachnoid haemorrhage.

Investigations to detect aneurysms in relatives

1.4.15

Explain to people (and their families if appropriate) who have had an aneurysmal subarachnoid haemorrhage and are concerned about possible aneurysms in their relatives that:

  • routine testing to check for aneurysms in relatives has not been shown to save lives or prevent aneurysmal subarachnoid haemorrhages

  • testing for relatives is based on an assessment of the relative's own risk

  • testing is usually limited to people with at least 2 first-degree relatives (father, mother, sister or brother) who have had an aneurysmal subarachnoid haemorrhage.

    Tell people where they can find more information about testing for relatives, such as the NHS webpage on diagnosis of brain aneurysm.

For a short explanation of why the committee made this recommendation and how it might affect practice, see the rationale and impact section on investigations to detect aneurysms in relatives.

Full details of the evidence and the committee's discussion are evidence review T: investigating relatives of people with aneurysmal subarachnoid haemorrhage.

1.5 Information and support

1.5.4

Adapt written and verbal information about aneurysmal subarachnoid haemorrhage to the needs and preferences of the person (and their family or carers if appropriate).

At diagnosis

1.5.5

Explain to the person (and their family or carers if appropriate) what an aneurysmal subarachnoid haemorrhage is and what the treatment options are, including their benefits and risks.

During the hospital stay

1.5.6

Give the person (and their family or carers if appropriate) information about complications that can happen after an aneurysmal subarachnoid haemorrhage, such as:

  • a build-up of fluid on the brain (hydrocephalus)

  • a reduced supply of blood to the brain (delayed cerebral ischaemia)

  • speech or communication difficulties

  • physical disabilities

  • seizures.

1.5.7

Tell the person (and their family or carers if appropriate) that common symptoms reported by people who have had a subarachnoid haemorrhage include:

  • headaches, fatigue and sleep disturbances

  • anxiety, low moods and increased irritability

  • problems with memory and cognitive function

  • changes to smell, taste, hearing or vision.

1.5.8

Give people who wish to receive it (and their family or carers if appropriate) information about their estimated future risk of another subarachnoid haemorrhage. Base the information on specialist assessment by the MDT of the person's medical circumstances, including:

  • the effectiveness of the treatment of the ruptured aneurysm

  • the presence and growth of additional aneurysms

  • their smoking status.

1.5.9

Give the person advice on returning to their usual activities including work, exercise, driving and sexual activity.

At discharge

1.5.10

Check that the person has been given advice about wound care and medicines, a copy of their follow-up care plan and details of who to contact at their specialist centre if they have questions or concerns. Give them details of local and national support groups.

At follow-up

1.5.11

Discuss the person's return to their usual activities (see recommendation 1.5.9).

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on information and support.

Full details of the evidence and the committee's discussion are in evidence review S: patient information and evidence review N: risk of subsequent subarachnoid haemorrhage.

Terms used in this guideline

This section defines terms that have been used in a particular way for this guideline.

Senior clinical decision-maker

A clinician with the necessary training and experience to assess people with suspected subarachnoid haemorrhage, confirm subarachnoid haemorrhage symptoms and signs, and refer people for further investigation. This may be a consultant, a staff-grade, associate-specialist or specialty doctor, or a doctor in a training grade who has been delegated to do this because they have the necessary competencies.