SUBARACHNOID HEMORRHAGE
Management of subarachnoid hemorrhage
Created 01/04/2021, last revision 03/12/2023
Standard management of SAH focuses on:
- blood pressure control and maintenance of normovolemia
- prevention and treatment of vasospasms
- elimination of the aneurysm from the circulation
- prevention and management of complications (both intra- and extracerebral)
General therapy and patient monitoring
- the initial management of patients with SAH is directed toward stabilizing the patient
- perform a basic neurological examination, assess the level of consciousness (LOC), airway, breathing, and circulation (ABCs)
- endotracheal intubation should be performed in patients presenting with coma, decreased level of consciousness, inability to protect the airway, or increased intracranial pressure (ICP)
- patients with signs of increased ICP or herniation should be hyperventilated (target pCO2 of 30-35 mm Hg)
- while there are some specifics in the conservative treatment of SAH (see tabs), the principles of general stroke management and management of intracranial hypertension apply
Laboratory studies and other methods
- serum chemistry panel – a baseline for detecting future complications
- natremia should be checked repeatedly
- CBC – evaluates potential infection or hematologic abnormalities
- prothrombin time (PT) and activated partial thromboplastin time (aPTT) to rule out coagulopathy
- blood typing/screening – to be ready for potential transfusion
- cardiac enzymes, cardiac troponin
- to exclude possible myocardial ischemia
- predictor of pulmonary and cardiac complications
- a correlation was found between troponin levels and neurological complications and outcome
- arterial blood gas (ABG) – required in respiratory-compromised patients
- a baseline chest X-ray
- ECG + ECG monitoring, transthoracic echocardiogram
- differentiate myocardial ischemia from common benign changes
- patients with SAH can experience myocardial ischemia due to the increased level of circulating catecholamines or autonomic stimulation from the brain
- nonspecific ST and T wave changes
- decreased PR intervals
- prolonged QRS intervals
- prolonged QT intervals
- presence of U waves
- arrhythmias – premature ventricular contractions (PVCs), supraventricular tachycardia (SVT), and bradyarrhythmias
Rebleeding prevention – timing
- rebleeding prevention is essential in SAH management – the risk is highest in the first few days (4% within the first 24 h) and decreases over time
- risk factors for rebleeding:
- decompensated hypertension
- aneurysm size and shape
- the severity of initial bleeding, incl. ICH or IVH
- seizures
- the most effective prevention is to treat the source ASAP (acute procedure, ideally within 24 hours) if the clinical condition of the patient permits
- thanks to vasospasm monitoring by TCD/TCCD, surgery can be performed even after 72 hours in the absence of spasm
- endovascular treatment is possible even in the presence of vasospasm (and can be combined with PTA/vasodilatation)
- early intervention allows subsequent full conservative therapy to prevent cerebral vasospasms
- indication for urgent neurosurgery:
- acute hydrocephalus requiring EVD
- life-threatening ICH (hematoma evacuation + aneurysm clipping)
- deferred management (elective procedures) should be chosen in the following cases:
- presence of vasospasms when clipping is indicated
- severe patient condition (Hunt-Hess IV-V, severe comorbidities)
- difficult, complex aneurysm
- incomplete endovascular team (e.g., at night)
- aneurysms where parent artery occlusion is considered
- it is optimal to verify collateral circulation by balloon occlusion test (BTO). However, due to heparin use, it is not suitable for the acute stage of bleeding
Hunt-Hess score | |
I-III | indication for acute intervention |
IV-V | the procedure is indicated in the presence of an expanding hematoma; otherwise, the indication is uncertain (the outcome of acutely operated and non-operated patients does not differ significantly) |
Rebleeding prevention – methods
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Craniotomy and aneurysm clipping |
- the advantage of clipping is the immediate and permanent removal of the aneurysm from the circulation
- some aneurysms are not treatable due to their shape/location
Endovascular procedures |
- in acute SAH, coiling alone should be performed (the use of stents and diverters requires antiplatelet therapy)
- the aneurysm sac is usually filled with detachable platinum coils that induce local thrombosis
- it takes some time for the aneurysm to be completely removed from the circulation; partial filling of the sac may occur, and repeated embolization is sometimes necessary (perform a control vascular imaging after the procedure)
- rebleeding rate is slightly higher than with clipping
- this method is preferred for aneurysms with a narrow neck (ideally < 5 mm) in the posterior circulation and for patients with more severe neurological deficits, cerebral edema, or older age with comorbidities
- the use of flow diverters, stents, or balloon-assisted coiling extends the indications for endovascular management to aneurysms with wider necks (mostly in elective procedures)
Deconstructive procedures |
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Other surgical procedures
- external ventricular drainage (EVD) for obstructive hydrocephalus + ICP monitoring
- lumbar CSF drainage for hyporesorptive hydrocephalus, typically for 5-7 days, with the evacuation of 100-200mL of CSF per 24h
- trepanation and insertion of a micro-sensor for ICP (ventricular, parenchymal) and/or tissue monitoring
- ICH evacuation (combined with clipping)
- decompressive craniectomy
Therapy results
- effectiveness of aneurysm treatment is measured by the rebleeding rate and clinical outcome
- ISAT (The International Subarachnoid Aneurysm Trial) was a prospective randomized trial comparing endovascular treatment with surgical clipping
- only patients eligible for both treatments were enrolled at centers performing both treatments (n=2143)
- the primary endpoint was the prevention of disability (mRS 3-5) and death from SAH within one year after treatment
- coiling was more likely to result in independent survival at 1 year than neurosurgical clipping; the survival benefit continued for at least 7 years
- dependency or death: 23% (endovascular) vs. 30.6% (clipping), the benefit continues > 7 years
- risk of rebleeding was relatively low but more common after coiling compared to clipping – 1.6% (coiling) vs. 0.7% (clipping)
- in both groups, rebleeding occurred most frequently during the first 30 days after aneurysm treatment, and rebleeding was associated with up to 50% mortality in both groups
- CARAT (Cerebral Aneurysm Rerupture After Treatment)
- the rebleeding rate was higher in the embolized patients (3.4% vs. 1.3%)
- rebleeding in coiled patients was mostly seen in angiographically incompletely filled aneurysms
- factors leading to incomplete aneurysm occlusion are:
- larger aneurysms (> 10 mm)
- wide neck (> 4 mm)
Follow-up
- long-term follow-up is recommended (especially in patients with incomplete occlusion) → increased risk of recurrence or regrowth of the treated aneurysm or development of de novo aneurysm(s)
- in the ISAT trial, the risk of recurrent aSAH from the target aneurysms in the endovascularly treated and surgically treated groups in the first 30 days after treatment was 1.9% and 0.6%, respectively
- In the ISAT trial, the risk of recurrent SAH from the target aneurysms in the endovascularly treated and surgically treated groups at 30 days to 1 year was 0.6% and 0.4%, at 1-5 years was 0% and 0%, and at >5 years was 0.5% and 0.3%, respectively
- in the ISAT trial, the risk of recurrent aSAH from the target aneurysms in the endovascularly treated and surgically treated groups in the first 30 days after treatment was 1.9% and 0.6%, respectively
- incomplete aneurysm occlusion
- associated with a higher risk of rerupture (however, even completely obliterated aneurysms carry a risk of rerupture in the long term)
- a higher rate of incomplete occlusion is associated with coiling compared to clipping
- imaging (perioperative and long-term) is recommended to evaluate for remnants or recurrence that may require treatment
- de novo aneurysm formation
- risk is approx. 0.3% at 1-5 years, and 0.3% at >5 years
- risk factors include younger age, family history, and multiple aneurysms
- risk factors for growth and rupture of de novo aneurysms include female sex, shorter interval to formation of the de novo aneurysm, multiple aneurysms, and larger size