Confirmed aneurysmal SAH (adult)
SAH on CT or LP, with an aneurysm on CTA or DSA. Transfer early to a centre with neurosurgery, neurointervention and neuro-ICU.
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NeurosurgeryManagement
Aneurysmal SAH - Neurosurgical Management (AHA 2023)
Aneurysmal SAH - Neurosurgical Management (AHA 2023): Confirmed aneurysmal SAH (adult) → On an anticoagulant? Reverse it now → Before repair: ICU care a...
Pathway Overview
17 steps
Algorithm Steps
17 total
01Start 02Warning On an anticoagulant? Reverse it now
Before the aneurysm is secured. Stop all anticoagulants and antiplatelets (recent coronary stent: involve cardiology). Doses: local reversal protocol.
- Warfarin: IV vitamin K plus 4-factor PCC
- Dabigatran: idarucizumab
- Factor Xa inhibitor: 4-factor PCC (andexanet is not TGA-registered). Heparin: protamine
03Action Before repair: ICU care and BP control
Aim: prevent rebleeding and secondary brain injury until the aneurysm is secured.
- ICU or neuro high-dependency care; frequent neuro checks (GCS, pupils)
- Low GCS or cannot protect the airway: intubate; avoid hypoxia, high CO2 and BP surges at induction
- Frequent BP checks. Short-acting IV agents. Avoid severe hypertension, hypotension and BP swings
- No proven BP target. If SBP >180-200 mmHg, lower it gradually. Keep MAP 65 mmHg or more. Earlier guidelines used SBP <160 mmHg
- Treat pain and nausea; stool softener; avoid straining
- Mechanical VTE prophylaxis (IPC) from admission; no drug prophylaxis until repair
- Do not give tranexamic acid routinely (no functional benefit)
- Pregnant: involve obstetrics early; do not delay imaging or repair
04Action Start enteral nimodipine now (adult)
Give to all patients with aSAH. Enteral only (oral or NG). Never inject an oral product IV.
- Adult: nimodipine 60 mg (AU: 2 x 30 mg tablets) every 4 hours, orally or by NG tube. NG: prepare as pharmacy advises
- Start as soon as possible, within 96 hours of onset. Course: 21 days (AHA, US label); AU PI oral-only course: 10-14 days
- Hepatic impairment: 30 mg every 4 hours
- Low BP: treat it and keep giving nimodipine if possible. Stop briefly only for marked BP instability. Caution if SBP <100 mmHg
- Contraindicated with rifampicin, phenytoin, carbamazepine or phenobarbital (loss of effect)
- CYP3A4 inhibitors (azoles, macrolides, ritonavir, valproate, fluoxetine, grapefruit): more hypotension; monitor BP, reduce dose if needed
05Action Acute hydrocephalus with drowsiness: urgent CSF drainage
Drowsy or falling GCS with enlarged ventricles on CT. Do not wait for aneurysm repair.
- EVD by neurosurgery; use an EVD bundle (insertion, care, monitoring)
- Lumbar drain only if the neurosurgeon confirms communicating hydrocephalus and no mass effect
- If a stent or flow diverter is likely: place the EVD before antiplatelets
- Watch for infection and for rebleeding
06Action Grade clinical severity
Use WFNS or Hunt and Hess after resuscitation. Good grade: I-III. Poor grade: IV-V.
- WFNS I: GCS 15, no motor deficit
- WFNS II: GCS 13-14, no motor deficit. WFNS III: GCS 13-14 with motor deficit
- WFNS IV: GCS 7-12. WFNS V: GCS 3-6
- Hunt and Hess: I mild headache; II severe headache, neck stiffness or cranial nerve palsy; III drowsy, confused or mild deficit; IV stupor, hemiparesis; V deep coma
- Modified Fisher grade (blood on CT) predicts DCI risk
07Action Assess the aneurysm (CTA or DSA)
DSA if CTA is not diagnostic or to plan treatment.
- Location; other aneurysms
- Size (giant: 25 mm or more); neck width (wide neck: 4 mm or more, or dome-to-neck ratio <2)
- Branch vessels from the dome or neck
- Intracerebral haematoma and its volume
- Blister or fusiform aneurysm: needs a different plan (flow diverter or complex surgery)
- Mycotic (infective) aneurysm: not covered by this pathway; infectious diseases and neurovascular team
08Warning Secure the aneurysm early: preferably within 24 hours
As early as feasible after presentation, whatever the day since onset. Poor grade: same aim if the patient is salvageable.
- Early repair lowers the risk of rebleeding, which is often fatal
- Presenting on day 4-10: do not postpone repair until after the vasospasm period
- Choose the method with both a neurosurgeon and a neurointerventionalist
09Action Choose the repair method: coiling or clipping
Team decision (neurosurgeon and neurointerventionalist) on patient and aneurysm features.
- Posterior circulation, amenable to coiling: coiling (AHA Class 1)
- Anterior circulation, good grade, suits both: primary coiling; better 1-year function (AHA Class 1)
- Large haematoma with reduced consciousness: emergency clot evacuation and clipping (AHA Class 1)
- Age under 40: clipping may be preferred for durability (AHA Class 2b). Over 70: no proven advantage for either
- MCA aneurysm, or anatomy not suitable for coiling (for example, a branch from the dome): clipping often favoured
- Function at 5 years is similar with either. After coiling: more recurrence and retreatment
- Not suitable for either: team considers stent-assisted coiling or flow diverter
10Action If coiling chosen: endovascular coiling
Aim for complete occlusion. If that is not feasible, secure the rupture site now and retreat later.
- Primary or balloon-assisted coiling first
- Do not use a stent or flow diverter if coiling or clipping can secure the aneurysm (harm)
- Stent or flow diverter needed: dual antiplatelets; higher bleeding risk, especially around an EVD
- Partial occlusion: retreat, usually within 1-3 months, if recovery allows
- Imaging after the procedure to confirm occlusion
11Action If clipping chosen: microsurgical clipping
Craniotomy and clip across the aneurysm neck.
- Evacuate a haematoma at the same operation if present
- Confirm occlusion during surgery (ICG or angiography)
- Imaging after surgery (CTA or DSA) to find a remnant
- Remnant: plan retreatment
12Action After repair: prevent and detect DCI
Highest risk from day 3 to day 14. Continue nimodipine.
- Keep euvolaemia with goal-directed fluids. Do not give prophylactic hypervolaemia or induced hypertension (harm)
- Frequent neuro checks by trained nurses
- TCD: mean MCA velocity 120 cm/s or more with Lindegaard ratio 3 or more suggests vasospasm
- New deficit: CTA or CT perfusion. Poor grade or unreliable exam: consider cEEG
- Statins and IV magnesium: not recommended
13Action After repair: medical care
Treat complications that worsen outcome.
- Drug VTE prophylaxis once the aneurysm is secured (timing after craniotomy or EVD: neurosurgery). Keep IPC until then
- No routine seizure prophylaxis; consider only if high risk. Do not use phenytoin
- Seizure: antiseizure medicine for up to 7 days
- Low sodium: do not fluid-restrict; fludrocortisone is reasonable (watch potassium)
- Control glucose and avoid hypoglycaemia; treat fever
- Ventilated more than 24 hours: ICU care bundle
14Action New deficit or fall in GCS: exclude other causes, then treat DCI
Urgent CT for rebleeding and hydrocephalus. Check sodium, glucose and oxygen. EEG if seizure possible.
- Keep euvolaemia; do not induce hypervolaemia
- Aneurysm secured: raising SBP may be reasonable (AHA Class 2b). No proven target; ICU team sets it
- Severe vasospasm: intra-arterial vasodilator or angioplasty may be reasonable (AHA Class 2b)
- Cardiac dysfunction (stunned myocardium): assess the heart before vasopressors or extra fluid
- Avoid hypotension, hypoxia and fever
15Action Late hydrocephalus: watch, and shunt if chronic
Chronic symptomatic hydrocephalus: permanent CSF shunt (AHA Class 1).
- Signs: slow decline, poor recovery, gait or cognitive change, failed EVD wean
- EVD in place: bundle protocol; watch for infection
- Fenestration of the lamina terminalis: not for routine use
16Action Follow-up imaging and recovery
Image after repair to find a remnant, recurrence or new aneurysm.
- Coiled: imaging at least once at 12 months or later
- Clipped: no long-term imaging if imaging within 6 months shows complete occlusion
- Partial occlusion or newer device (flow diverter, intrasaccular): long-term imaging
- Young age, family history of aSAH or polycystic kidney disease: screen for new aneurysms every 5 years
- Stop smoking; treat hypertension
- Screen for cognitive, mood and fatigue problems; multidisciplinary rehabilitation
17Outcome Outcome and prognosis
Case fatality is about 40%. Many survivors have lasting deficits.
- Main causes of poor outcome: the first bleed, rebleeding, DCI and hydrocephalus
- Cognitive, mood and quality-of-life problems are common and can persist
Guideline Source
2023 AHA/ASA Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage (Hoh BL et al., Stroke 2023;54:e314-e370)
Clinical Safety Information
Clinical Decision Support — Not a Substitute for Clinical Judgment
Individual patient factors may require deviation from these recommendations.
Known Limitations
- Adults only. Not for mycotic, traumatic or non-aneurysmal (perimesencephalic) SAH.
- Repair method needs a neurosurgeon and a neurointerventionalist; local expertise affects the choice.
- No proven BP target before repair or during DCI.
- Flow diverters and intrasaccular devices in ruptured aneurysms: limited evidence.
Contraindicated Populations
Children (under 18 years)Mycotic (infective) aneurysmNon-aneurysmal perimesencephalic SAHTraumatic SAH
Applicable Regions
USEUAU
AU: Andexanet is not on the ARTG; use 4-factor PCC per local protocol. Nimotop AU PI gives a 10-14 day oral-only course; many units give 21 days (AHA, US label). Follow the local protocol.
EU: ESO/EANS/ESMINT 2026 aSAH guideline agrees on early repair, coiling when both suit, oral nimodipine and no routine antifibrinolytics; follow-up imaging intervals are from ESO 2026.
US: AHA/ASA 2023 guideline is the primary source.
Version 2Next review: 2027-09-30
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Frequently Asked Questions
What is the Aneurysmal SAH - Neurosurgical Management (AHA 2023)?
The Aneurysmal SAH - Neurosurgical Management (AHA 2023) is a management clinical algorithm for Neurosurgery. It provides a structured decision tree to guide clinical decision-making, based on 2023 AHA/ASA Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage (Hoh BL et al., Stroke 2023;54:e314-e370).
What guideline is the Aneurysmal SAH - Neurosurgical Management (AHA 2023) based on?
This algorithm is based on 2023 AHA/ASA Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage (Hoh BL et al., Stroke 2023;54:e314-e370) (DOI: 10.1161/STR.0000000000000436).
What are the limitations of the Aneurysmal SAH - Neurosurgical Management (AHA 2023)?
Known limitations include: Adults only. Not for mycotic, traumatic or non-aneurysmal (perimesencephalic) SAH.; Repair method needs a neurosurgeon and a neurointerventionalist; local expertise affects the choice.; No proven BP target before repair or during DCI.; Flow diverters and intrasaccular devices in ruptured aneurysms: limited evidence.. Individual patient factors may require deviation from these recommendations.
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