Subarachnoid haemorrhage

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

ACUTE

GCS score ≤8 or falling

1st line – cardiopulmonary support

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1st line –

cardiopulmonary support

Use an ABC approach that includes the following.[39]

Protect the airway with simple airway manoeuvres and adjuncts (e.g., oropharyngeal or nasopharyngeal airways).

Call the anaesthetist. This is standard practice in the UK. In some countries, intubation and sedation/paralysis are performed by a trained team in the emergency department.

Cerebroprotective induction is required to protect against laryngoscopy-induced increases in intracranial pressure.

As soon as the diagnosis of SAH is confirmed, urgently discuss with a specialist neurosurgical centre the need for transfer of care of the patient to the specialist centre.[37]

Do not use a SAH severity score in isolation to determine the need for, or timing of, transfer of care to a specialist neurosurgical centre.[37][49]

Monitor controlled oxygen therapy. An upper SpO₂ limit of 96% is reasonable when administering supplemental oxygen to most patients with acute illness who are not at risk of hypercapnia. Evidence suggests that liberal use of supplemental oxygen (target SpO₂ >96%) in acutely ill adults is associated with higher mortality than more conservative oxygen therapy.[45] A lower target SpO₂ of 88% to 92% is appropriate if the patient is at risk of hypercapnic respiratory failure.[46]

Use isotonic/normal saline as fluid resuscitation to restore normovolaemia.[39]

Start with 3 L/day (isotonic/normal saline 0.9%), and adjust infusion for oral intake and supplement other electrolytes as necessary.[39]
Avoid all hypotonic fluids.

Plus – supportive care and monitoring

Back

Plus –

supportive care and monitoring

Treatment recommended for ALL patients in selected patient group

Observe the patient continuously at least until occlusion of the aneurysm.[39]

Use the Glasgow Coma Scale (serial) but be aware that the need for monitoring clinically neurological status in these patients must be balanced against the risk of harm from an unsecured aneurysm or inadequate spontaneous ventilation. [ Glasgow Coma Scale Opens in new window ] If in doubt, consult with the anaesthetist and neurosurgeon.

When conducting a neurological assessment, check the patient’s care record and if opioid analgesia has been given, take into account its sedating and pupillary effects.[37]

Check pupils for size, shape, and reactivity to light every 20 minutes once the patient is sedated and paralysed. Discuss any pupil changes with the neurosurgeon.

Fixed and dilated pupils (especially if bilateral) in comatose patients are associated with poor prognosis.[47] Consider immediate hypertonic saline or mannitol.

If the patient is acutely deteriorating (e.g., new focal neurological deficit, seizure, or sudden drop in the patient's level of consciousness) have a high suspicion for rebleed or acute hydrocephalus.[37]

If you suspect a rebleed or acute hydrocephalus, consult with a neurosurgeon and arrange an urgent non-contrast computed tomography (CT) head rescan.

Practical tip

While overlapping features can make it hard to clinically differentiate the neurological complications of SAH, the following may provide some clues before the aneurysm is secured.

Think rebleed if there:

Is a sudden drop in conscious level
Is a spike in blood pressure
Is tonic/extensor posturing
Are pupillary changes.

Think hydrocephalus if there is:

A gradually worsening level of arousal with relative preservation of deliberate motor responses ± severe headache/vomiting/agitation.

Monitor ECG continuously for arrhythmias that could cause haemodynamic instability.

Blood pressure (BP)

Monitor BP continuously via an arterial line.[39]

Maintain systolic blood pressure (SBP) <180 mmHg until occlusion of aneurysm.[39]
- If SBP remains high, consider further lowering of blood pressure.
- Maintain the mean arterial pressure at least >90 mmHg if BP is lowered.
Stop any antihypertensive medication and do not treat hypertension unless it is extreme.[39]

Practical tip

A reduction in BP may be already achieved by giving nimodipine (to prevent delayed cerebral ischaemia).[39] Nimodipine is a potent cerebral vasodilator and may cause systemic hypotension in some patients.

Cardiac complications

Refer urgently to a cardiologist if there are any ECG changes. The most common include:

Arrhythmias and ischaemic changes[56][81][82][84]
Prolonged QTc
ST segment/T-wave abnormalities.

Practical tip

Patients with SAH may have ECG changes that mimic acute coronary syndrome and ST-elevation myocardial infarction. Seek specialist advice when deciding whether to perform a computed tomography head scan before or after coronary angiography. Use your clinical judgement alongside specialist input to weigh up the likelihood of the patient having SAH versus acute coronary syndrome.[85]

Acute heart failure may require the use of inotropes to treat pulmonary oedema or hypotension.

Fever

Monitor temperature continuously.

Give routine antipyretic medication (e.g., paracetamol) and apply cooling blankets to aim for normothermia.[39]

Hyponatraemia

Treat moderate to severe hyponatraemia (sodium levels <131 mmol/L [<131 mEq/L] ) with hypertonic saline 3%.[115][120]

Monitor sodium levels for response frequently. Monitor the rate and composition of the hypertonic solution, fluid balance and adjust accordingly.
Do not restrict fluid in patients with suspected syndrome of inappropriate antidiuretic hormone secretion (SIADH) in the first few weeks after SAH.

Hyperglycaemia

Follow your local protocol.

European guidelines recommend treating hyperglycaemia over 10 mmol/L.[39]

Prevention of deep vein thrombosis and pulmonary embolism

Use compression stockings and intermittent compression by pneumatic devices in high-risk patients before occlusion of the aneurysm.[39]

Consider adding low molecular weight heparin (LMWH) not earlier than 12 hours after surgical occlusion of the aneurysm and immediately after coiling.[39]

In practice in the UK, prescription of LMWH will be prompted if appropriate once you have recorded your venous thromboembolism risk assessment in the patient’s electronic record.

Consider – nimodipine (to prevent delayed cerebral ischaemia)

Back

Consider –

nimodipine (to prevent delayed cerebral ischaemia)

Additional treatment recommended for SOME patients in selected patient group

Consider enteral nimodipine for all patients with confirmed SAH.[37][133] In practice, the decision to start nimodipine should be made by a neurosurgeon; if a neurosurgeon is not available, a critical care specialist should make this decision. If used, nimodipine should be given for 14 to 21 days.[39][40]

Only use intravenous nimodipine within a specialist setting and if enteral treatment is not suitable.[37][133]
If nimodipine is potentially contraindicated (e.g., after recent myocardial infarction), seek specialist advice.
Nimodipine is a dihydropyridine calcium-channel blocker that relaxes and widens blood vessels. Limited evidence shows some reductions in mortality, rebleeding, disability, and delayed cerebral ischaemia with nimodipine.[37][133] Although nimodipine is widely used in practice, there is uncertainty about its benefits owing to the lack of compelling contemporary data.[37][133]

Practical tip

Monitor BP after giving nimodipine to prevent hypotension and decreased cerebral perfusion.[39] Nimodipine is a potent cerebral vasodilator and may cause systemic hypotension in some patients.

Evidence: Nimodipine use and route of administration

Nimpodipine may reduce mortality, rebleeding, disability, and delayed cerebral ischaemia in people with SAH. However, this effect is uncertain and based on early evidence, before current best practice in securing ruptured aneurysms. Intravenous nimodipine is unlikely to be cost-effective in most situations. Therefore, administration should be via the enteral route where possible.

The UK National Institute for Health and Care Excellence (NICE) advises to consider enteral nimodipine (oral or via nasogastric tube) for people with a confirmed subarachnoid haemorrhage and to only use the intravenous route in specialist settings if enteral treatment is unsuitable (e.g., patients with poor drug absorption).[37][133]

Limited evidence showed some reduction in mortality, rebleeding, disability, and delayed cerebral ischaemia with nimodipine compared with placebo (7 randomised controlled trials [RCTs]) or no nimodipine (1 RCT).
- Most of the evidence was assessed by NICE as low or very low quality using the GRADE approach, with wide confidence intervals meaning there was uncertainty about the clinical significance of many results.
- All included studies were conducted in the 1980s. Since then there have been significant changes in neurosurgical management, raising some concerns about the applicability to current clinical practice.
- Four studies included intravenous nimodipine. Intravenous nimodipine is expensive and only used in an intensive care setting. The guideline committee felt it was unlikely to be cost-effective in most patients, including those who are unconscious, ventilated, or otherwise unable to swallow, where the enteral route via a nasogastric tube is still preferable.
As there is no evidence of significant harms with nimodipine, and there remains a potential benefit, NICE made a weak recommendation to consider using nimodipine, while also making a research recommendation to evaluate whether nimodipine still has a role in the treatment of SAH.

Primary options

nimodipine: 60 mg orally every 4 hours

Consider – anticonvulsant

Consider – stop and reverse anticoagulation

Plus – endovascular coiling or surgical clipping or conservative management

Back

Plus –

endovascular coiling or surgical clipping or conservative management

Treatment recommended for ALL patients in selected patient group

An interventional neuroradiologist and a neurosurgeon should decide the best mode of intervention to manage the culprit aneurysm, taking into account the patient's clinical condition, the characteristics of the aneurysm, and the amount and location of subarachnoid blood.[37][39] A proposed treatment plan should be documented, in discussion with the patient, and their family or carers if appropriate, based on the following options:[37]

Interventional treatment with endovascular coiling or neurosurgical clipping
No interventional procedure, with monitoring to check for clinical improvement and reassess the options for treatment.

Practical tip

Older patients should not be excluded from treatment of the aneurysm based solely on their age. The decision to treat actively should take into account the patient’s clinical condition.[39]

Do not use a SAH severity score in isolation to determine the suitability of any management option.[37]

If interventional treatment via endovascular coiling or neurosurgical clipping is planned, this should be carried out at the earliest opportunity to prevent rebleeding. The risk of rebleeding is highest within 24 hours of the onset of symptoms.[37]

Endovascular coiling is the treatment of choice in ruptured aneurysms that can be equally effectively treated with either coiling or clipping.[37][39][140] [ ] [Evidence B] Neurosurgical clipping should be considered if endovascular coiling is not suitable.[37]

Interventional treatment is not suitable for some patients with aneurysmal SAH, including those whose clinical condition is poor (e.g., patients with severe neurological deficit, impaired consciousness, or requirement for ventilatory support).[141] If an interventional procedure is not deemed to be suitable, the patient should be monitored for clinical improvement and the options for treatment reassessed as appropriate.[37]

Consider – ventriculostomy or lumbar drainage of cerebrospinal fluid for acute hydrocephalus

Back

Consider –

ventriculostomy or lumbar drainage of cerebrospinal fluid for acute hydrocephalus

Additional treatment recommended for SOME patients in selected patient group

If you suspect acute hydrocephalus (i.e., gradually worsening level of arousal with relative preservation of deliberate motor responses ± severe headache/vomiting/agitation), consult with a neurosurgeon and arrange an urgent non-contrast computed tomography (CT) head rescan. Acute hydrocephalus can lead to severe disability or death if not treated promptly.[37][121]

The neurosurgeon may consider drainage or diversion of cerebrospinal fluid for a patient with neurological deterioration caused by acute hydrocephalus.[37][122]
Either drainage or diversion could be considered. There is no evidence on the effectiveness of different techniques for drainage or diversion in acute hydrocephalus.[37]

GCS score ≥9

1st line – supportive care and monitoring

Back

1st line –

supportive care and monitoring

As soon as the diagnosis of SAH is confirmed, urgently discuss with a specialist neurosurgical centre the need for transfer of care of the patient to the specialist centre.[37] Do not use a SAH severity score in isolation to determine the need for, or timing of, transfer of care to a specialist neurosurgical centre.[37][49]

Observe the patient continuously at least until occlusion of the aneurysm.[39]

Neurological status

Use the Glasgow Coma Scale (GCS) (serial). [ Glasgow Coma Scale Opens in new window ]

When conducting a neurological assessment, check the patient’s care record and if opioid analgesia has been given, take into account its sedating and pupillary effects.[37]

If you suspect a rebleed or acute hydrocephalus, consult with a neurosurgeon and arrange an urgent non-contrast CT head rescan.

Practical tip

While overlapping features can make it hard to clinically differentiate the neurological complications of SAH, the following may provide some clues before the aneurysm is secured.

Think rebleed if there:

Is a sudden drop in conscious level
Is a spike in blood pressure
Is tonic/extensor posturing
Are pupillary changes.

Think hydrocephalus if there is:

A gradually worsening level of arousal with relative preservation of deliberate motor responses ± severe headache/vomiting/agitation.

If a patient with GCS score ≥9 deteriorates to GCS score ≤8, follow protocol for patient group GCS score ≤8 or falling and consult with a neurosurgeon immediately.

Blood pressure (BP)

Monitor BP continuously via an arterial line.[39]

Maintain systolic blood pressure (SBP) <180 mmHg until occlusion of aneurysm.[39]
- If SBP remains high, consider further lowering of blood pressure.
- Maintain the mean arterial pressure at least >90 mmHg if BP is lowered.
Stop any antihypertensive medication and do not treat hypertension unless it is extreme.[39]

Practical tip

A reduction in BP may be already achieved by giving nimodipine (to prevent delayed cerebral ischaemia) and analgesia (to treat pain).[39] Nimodipine is a potent cerebral vasodilator and may cause systemic hypotension in some patients. Elevated BP following SAH is often due to pain, anxiety, and generalised sympathetic activation.

Cardiac complications

Refer urgently to a cardiologist if there are any ECG changes. The most common include:

Arrhythmias and ischaemic changes[56][81][82][84]
Prolonged QTc
ST segment/T-wave abnormalities.

Practical tip

Acute heart failure may require the use of inotropes to treat pulmonary oedema or hypotension.

Fever

Monitor temperature continuously.

Give routine antipyretic medication (e.g., paracetamol) and apply cooling blankets to aim for normothermia.[39]

Only give an antipyretic medication if an analgesic without antipyretic properties (e.g., opioid) is being used. If paracetamol is being used as an analgesic, this is also a suitable antipyretic.

Hyponatraemia

Treat moderate to severe hyponatraemia (sodium levels <131 mmol/L [<131 mEq/L] ) with hypertonic saline 3%.[115][120]

Monitor sodium levels for response frequently. Monitor the rate and composition of the hypertonic solution, fluid balance and adjust accordingly.
Do not restrict fluid in patients with suspected syndrome of inappropriate antidiuretic hormone secretion (SIADH) in the first few weeks after SAH.

Hyperglycaemia

Follow your local protocol.

European guidelines recommend treating hyperglycaemia over 10 mmol/L.[39]

Prevention of deep vein thrombosis and pulmonary embolism

Use compression stockings and intermittent compression by pneumatic devices in high-risk patients before occlusion of the aneurysm.[39]

Consider adding low molecular weight heparin (LMWH) not earlier than 12 hours after surgical occlusion of the aneurysm and immediately after coiling.[39]

In practice in the UK, prescription of LMWH will be prompted if appropriate once you have recorded your venous thromboembolism risk assessment in the patient’s electronic record.

Consider – nimodipine (to prevent delayed cerebral ischaemia)

Back

Consider –

nimodipine (to prevent delayed cerebral ischaemia)

Additional treatment recommended for SOME patients in selected patient group

Only use intravenous nimodipine within a specialist setting and if enteral treatment is not suitable.[37][133]
If nimodipine is potentially contraindicated (e.g., after recent myocardial infarction), seek specialist advice.

Nimodipine is a dihydropyridine calcium-channel blocker that relaxes and widens blood vessels. Limited evidence shows some reductions in mortality, rebleeding, disability, and delayed cerebral ischaemia with nimodipine.[37][133] Although nimodipine is widely used in practice, there is uncertainty about its benefits owing to the lack of compelling contemporary data.[37][133]

Practical tip

Monitor BP after giving nimodipine to prevent hypotension and decreased cerebral perfusion.[39] Nimodipine is a potent cerebral vasodilator and may cause systemic hypotension in some patients.

Primary options

nimodipine: 60 mg orally every 4 hours

Consider – anticonvulsant

Plus – analgesia

Back

Plus –

analgesia

Treatment recommended for ALL patients in selected patient group

Provide analgesia in conscious patients.

Start with paracetamol. Avoid aspirin or non-steroidal anti-inflammatory drugs before aneurysm occlusion.[39]
For severe pain, give codeine or tramadol. If the patient is still in pain, give morphine or oxycodone.[39]
Document administration of opioid analgesia in the patient’s healthcare record.[37] Opioid analgesia may affect neurological assessment given its sedating and pupillary effects.[37]

Primary options

paracetamol: oral: 500-1000 mg orally every 4-6 hours when required, maximum 4000 mg/day; intravenous (<51 kg body weight): 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; intravenous (≥51 kg body weight): 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)

Secondary options

codeine phosphate: 30-60 mg orally/intramuscularly every 4 hours when required, maximum 240 mg/day

tramadol: 100 mg orally (immediate-release) initially, followed by 50-100 mg every 4-6 hours when required; maximum 400 mg/day; 50-100 mg intravenously every 4-6 hours when required

Tertiary options

morphine sulfate: 5-10 mg orally (immediate-release)/subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response

oxycodone: 5 mg orally (immediate-release) every 4-6 hours initially, adjust dose according to response, maximum 400 mg/day; 1-10 mg intravenously every 4 hours when required

Consider – stool softener and anti-emetic

Consider – stop and reverse anticoagulation

Plus – endovascular coiling or surgical clipping or conservative management

Back

Plus –

endovascular coiling or surgical clipping or conservative management

Treatment recommended for ALL patients in selected patient group

Interventional treatment with endovascular coiling or neurosurgical clipping
No interventional procedure, with monitoring to check for clinical improvement and reassess the options for treatment.

Practical tip

Older patients should not be excluded from treatment of the aneurysm based solely on their age. The decision to treat actively should take into account the patient’s clinical condition.[39]

Do not use a SAH severity score in isolation to determine the suitability of any management option.[37]

Consider – ventriculostomy or lumbar drainage of cerebrospinal fluid for acute hydrocephalus

Back

Consider –

ventriculostomy or lumbar drainage of cerebrospinal fluid for acute hydrocephalus

Additional treatment recommended for SOME patients in selected patient group

The neurosurgeon may consider drainage or diversion of cerebrospinal fluid for a patient with neurological deterioration caused by acute hydrocephalus.[37][122]
Either drainage or diversion could be considered. There is no evidence on the effectiveness of different techniques for drainage or diversion in acute hydrocephalus.[37]

ONGOING

with symptomatic vasospasm or DCI

1st line – referral to neurosurgeon

Use of this content is subject to our disclaimer

Subarachnoid haemorrhage

Treatment algorithm

GCS score ≤8 or falling

cardiopulmonary support

supportive care and monitoring

Practical tip

Blood pressure (BP)

Practical tip

Cardiac complications

Practical tip

Fever

Hyponatraemia

Hyperglycaemia

Prevention of deep vein thrombosis and pulmonary embolism

nimodipine (to prevent delayed cerebral ischaemia)

Practical tip

Evidence: Nimodipine use and route of administration

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

anticonvulsant

Prophylactic anticonvulsants

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

stop and reverse anticoagulation

Practical tip

endovascular coiling or surgical clipping or conservative management

Practical tip

ventriculostomy or lumbar drainage of cerebrospinal fluid for acute hydrocephalus

GCS score ≥9

supportive care and monitoring

Neurological status

Practical tip

Blood pressure (BP)

Practical tip

Cardiac complications

Practical tip

Fever

Hyponatraemia

Hyperglycaemia

Prevention of deep vein thrombosis and pulmonary embolism

nimodipine (to prevent delayed cerebral ischaemia)

Practical tip

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

anticonvulsant

Prophylactic anticonvulsants

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

analgesia

Primary options

Secondary options

Tertiary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Secondary options

Tertiary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

Secondary options

Tertiary options

stool softener and anti-emetic

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

stop and reverse anticoagulation

Practical tip