This is the current release of the guideline.

Aneurysmal subarachnoid hemorrhage

Patients with or at risk for aneurysmal subarachnoid hemorrhage

Prevention

1. Antihypertensive medication
2. Smoking cessation
3. Screening with noninvasive imaging and catheter angiography, when indicated

Diagnosis/Evaluation

1. Assessment of severity of headache and of initial bleed
2. Urgent evaluation and treatment
3. Assessment of risk of rebleed
4. Computed tomography (CT) scan
5. Lumbar puncture for analysis of cerebrospinal fluid (CSF)
6. Cerebral angiography
7. Magnetic resonance angiography (MRA) and computed tomography angiography (CTA)
8. Assessment of neurological impairment with grading system
9. Development of standardized emergency department (ED) management protocol

Treatment/Management

1. Surgical clipping or endovascular coiling
2. Complete obliteration of aneurysm whenever possible
3. Early versus delayed surgery
4. Early referral to specialist
5. Minimization of hypotension during surgery
6. Pharmacological strategies and induced hypertension
7. Induced hypothermia during surgery
8. Bedrest to prevent rebleeding

Cerebral Vasospasm

1. Oral nimodipine
2. Early management including maintaining normal circulating blood volume and avoiding hypovolemia
3. Volume expansion, induction of hypertension, and hemodilution (triple-H therapy)
4. Cerebral angiography and/or selective intraarterial vasodilator therapy

Hydrocephalus

1. Temporary or permanent cerebrospinal fluid diversion
2. Ventriculostomy

Seizures

Prophylactic anticonvulsants (not recommended for routine long-term use without specific risk factors)

Hyponatremia

1. Avoidance of large volumes of hypotonic fluids and intravascular volume contraction
2. Monitoring of volume status
3. Fludrocortisone acetate and hypertonic saline
4. Reduction of fluid administration in some instances

In an effort to update recommendations (prepared in 1994), a systematic literature review was conducted based on a search of MEDLINE to identify all relevant randomized clinical trials published between June 30, 1994, and November 1, 2006 (search terms: subarachnoid hemorrhage, cerebral aneurysm, trial; see Table 1 the original guideline document). Each identified article was reviewed by at least 2 members of the writing group. Selected articles had to meet one of the following criteria to be included: randomized trial or nonrandomized concurrent cohort study. Case series and nonrandomized historical cohort studies were reviewed if no studies with a higher level of evidence were available for a particular topic covered in the initial guidelines. These were chosen on the basis of sample size and the relevance of the particular studies to subjects that were covered in the initial guidelines.

Not stated

Levels of Evidence

Therapeutic Recommendations

Level of Evidence A: Data derived from multiple randomized clinical trials

Level of Evidence B: Data derived from a single randomized trial or nonrandomized studies

Level of Evidence C: Consensus opinion of experts

Diagnostic/Prognostic Recommendations

Level of Evidence A: Data derived from multiple prospective cohort studies using a reference standard applied by a masked evaluator

Level of Evidence B: Data derived from a single grade A study or ≥1 case-control studies or studies using a reference standard applied by an unmasked evaluator

Level of Evidence C: Consensus opinion of experts

Applying Classification of Recommendations and Level of Evidence

*Data available from clinical trials or registries about the usefulness/efficacy in different subpopulations, such as gender, age, history of diabetes, history of prior myocardial infarction, history of heart failure, and prior aspirin use. A recommendation with Level of Evidence B or C does not imply that the recommendation is weak. Many important clinical questions addressed in the guidelines do not lend themselves to clinical trials. Even though randomized trials are not available, there may be a very clear clinical consensus that a particular test or therapy is useful or effective.

Note: In 2003, the American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines developed a list of suggested phrases to use when writing recommendations. All guideline recommendations have been written in full sentences that express a complete thought, such that a recommendation, even if separated and presented apart from the rest of the document (including headings above sets of recommendations), would still convey the full intent of the recommendation. It is hoped that this will increase readers' comprehension of the guidelines and will allow queries at the individual recommendation level. (See Table 3 in the original guideline document for a list of suggested phrases for writing recommendations.)

Not stated

The Stroke Council of the American Heart Association (AHA) formed a writing group to reevaluate the recommendations for management of aneurysmal subarachnoid hemorrhage (SAH). A consensus committee reviewed existing data in this field and prepared the recommendations in 1994. In an effort to update those recommendations, a systematic literature review was conducted to identify all relevant randomized clinical trials published between June 30, 1994, and November 1, 2006. The committee's recommendations were made by applying the standard American Heart Association evidence rating scheme (see the "Rating Scheme for Strength of the Evidence" field).

Classes of Recommendation

Class I: Conditions for which there is evidence for and/or general agreement that the procedure or treatment is useful and effective

Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment

Class IIa: The weight of evidence or opinion is in favor of the procedure or treatment

Class IIb: Usefulness/efficacy is less well established by evidence or opinion

Class III: Conditions for which there is evidence and/or general agreement that the procedure or treatment is not useful/effective and in some cases may be harmful

Also see the table "Applying Classification of Recommendations and Level of Evidence" in the "Rating Scheme for the Strength of Evidence" field.

This statement was approved by the American Heart Association (AHA) Science Advisory and Coordinating Committee on October 3, 2008. Expert peer review of AHA Scientific Statements is conducted at the AHA National Center.

Definitions for the levels of evidence (A–C) and classes of recommendations (I–III) are provided at the end of the "Major Recommendations" field.

Prevention of Subarachnoid Hemorrhage (SAH): Summary and Recommendations

1. The relationship between hypertension and aneurysmal SAH is uncertain. However, treatment of high blood pressure with antihypertensive medication is recommended to prevent ischemic stroke, intracerebral hemorrhage, and cardiac, renal, and other end-organ injury (Class I, Level of Evidence A).
2. Cessation of smoking is reasonable to reduce the risk of SAH, although evidence for this association is indirect (Class IIa, Level of Evidence B).
3. Screening of certain high-risk populations for unruptured aneurysms is of uncertain value (Class IIb, Level of Evidence B); advances in noninvasive imaging may be used for screening, but catheter angiography remains the gold standard when it is clinically imperative to know if an aneurysm exists.

Natural History and Outcome of Aneurysmal SAH: Summary and Recommendations

1. The severity of the initial bleed should be determined rapidly because it is the most useful indicator of outcome after aneurysmal SAH, and grading scales that rely heavily on this factor are helpful in planning future care with family and other physicians (Class I, Level of Evidence B).
2. Case review and prospective cohorts have shown that for untreated, ruptured aneurysms, there is at least a 3% to 4% risk of rebleeding in the first 24 hours—and possibly significantly higher—with a high percentage occurring immediately (within 2 to 12 hours) after the initial ictus, a 1% per day to 2% per day risk in the first month, and a long-term risk of 3% per year after 3 months. Urgent evaluation and treatment of patients with suspected SAH are therefore recommended (Class I, Level of Evidence B).
3. In the triage of patients for aneurysm repair, factors that may be considered in determining the risk of rebleeding include severity of the initial bleed, interval to admission, blood pressure, gender, aneurysm characteristics, hydrocephalus, early angiography, and the presence of a ventricular drain (Class IIb, Level of Evidence B).

Manifestations and Diagnosis of SAH: Summary and Recommendations

1. SAH is a medical emergency that is frequently misdiagnosed. A high level of suspicion for SAH should exist in patients with acute onset of severe headache (Class I, Level of Evidence B).
2. Computed tomography (CT) scanning for suspected SAH should be performed (Class I, Level of Evidence B), and lumbar puncture for analysis of cerebrospinal fluid (CSF) is strongly recommended when the computed tomography scan is negative (Class I, Level of Evidence B).
3. Selective cerebral angiography should be performed in patients with SAH to document the presence and anatomic features of aneurysms (Class I, Level of Evidence B).
4. Magnetic resonance angiography (MRA) and CT angiography (CTA) may be considered when conventional angiography cannot be performed in a timely fashion (Class IIb, Level of Evidence B).

Emergency Evaluation and Preoperative Care: Summary and Recommendations

1. The degree of neurological impairment using an accepted SAH grading system can be useful for prognosis and triage (Class IIa, Level of Evidence B).
2. A standardized emergency department (ED) management protocol for the evaluation of patients with headaches and other symptoms of potential SAH currently does not exist and should probably be developed (Class IIa, Level of Evidence C).

Medical Measures to Prevent Rebleeding After SAH: Summary and Recommendations

1. Blood pressure should be monitored and controlled to balance the risk of stroke, hypertension-related rebleeding, and maintenance of cerebral perfusion pressure (Class I, Level of Evidence B).
2. Bedrest alone is not enough to prevent rebleeding after SAH. It may be considered a component of a broader treatment strategy, along with more definitive measures (Class IIb, Level of Evidence B).
3. Although older studies demonstrated an overall negative effect of antifibrinolytics, recent evidence suggests that early treatment with a short course of antifibrinolytic agents combined with a program of early aneurysm treatment followed by discontinuation of the antifibrinolytic and prophylaxis against hypovolemia and vasospasm may be reasonable (Class IIb, Level of Evidence B), but further research is needed. Furthermore, antifibrinolytic therapy to prevent rebleeding may be considered in certain clinical situations, e.g., in patients with a low risk of vasospasm and/or a beneficial effect of delaying surgery (Class IIb, Level of Evidence B).

Surgical/Endovascular Treatment of Ruptured Aneurysms: Summary and Recommendations

1. Surgical clipping or endovascular coiling should be performed to reduce the rate of rebleeding after aneurysmal SAH (Class I, Level of Evidence B).
2. Wrapped or coated aneurysms and incompletely clipped or coiled aneurysms have an increased risk of rehemorrhage compared with those that are completely occluded and therefore require long-term follow-up angiography. Complete obliteration of the aneurysm is recommended whenever possible (Class I, Level of Evidence B).
3. For patients with ruptured aneurysms judged by an experienced team of cerebrovascular surgeons and endovascular practitioners to be technically amenable to both endovascular coiling and neurosurgical clipping, endovascular coiling can be beneficial (Class I, Level of Evidence B). Nevertheless, it is reasonable to consider individual characteristics of the patient and the aneurysm in deciding the best means of repair, and management of patients in centers offering both techniques is probably indicated (Class IIa, Level of Evidence B).
4. Although previous studies showed that overall outcome was not different for early versus delayed surgery after SAH, early treatment reduces the risk of rebleeding after SAH, and newer methods may increase the effectiveness of early aneurysm treatment. Early aneurysm treatment is reasonable and is probably indicated in the majority of cases (Class IIa, Level of Evidence B).

Hospital Characteristics and Systems of Care: Summary and Recommendations

1. Early referral to high-volume centers that have both experienced cerebrovascular surgeons and endovascular specialists is reasonable (Class IIa, Level of Evidence B).

Anesthetic Management: Summary and Recommendations

1. Minimizing the degree and duration of intraoperative hypotension during aneurysm surgery is probably indicated (Class IIa, Level of Evidence B).
2. There are insufficient data on pharmacological strategies and induced hypertension during temporary vessel occlusion to make specific recommendations, but there are instances when their use may be considered reasonable (Class IIb, Level of Evidence C).
3. Induced hypothermia during aneurysm surgery may be a reasonable option in some cases but is not routinely recommended (Class III, Level of Evidence B).

Management of Cerebral Vasospasm: Summary and Recommendations

1. Oral nimodipine is indicated to reduce poor outcome related to aneurysmal SAH (Class I, Level of Evidence A). The value of other calcium antagonists, whether administered orally or intravenously, remains uncertain.
2. Treatment of cerebral vasospasm begins with early management of the ruptured aneurysm, and in most cases, maintaining normal circulating blood volume and avoiding hypovolemia are probably indicated (Class IIa, Level of Evidence B).
3. One reasonable approach to symptomatic cerebral vasospasm is volume expansion, induction of hypertension, and hemodilution (triple-H therapy) (Class IIa, Level of Evidence B).
4. Alternatively, cerebral angioplasty and/or selective intraarterial vasodilator therapy may be reasonable after, together with, or in the place of triple-H therapy, depending on the clinical scenario (Class IIb, Level of Evidence B).

Management of Hydrocephalus: Summary and Recommendations

1. Temporary or permanent cerebrospinal fluid diversion is recommended in symptomatic patients with chronic hydrocephalus after SAH (Class I, Level of Evidence B).
2. Ventriculostomy can be beneficial in patients with ventriculomegaly and diminished level of consciousness after acute SAH (Class IIa, Level of Evidence B).

Management of Seizures: Summary and Recommendations

1. The administration of prophylactic anticonvulsants may be considered in the immediate posthemorrhagic period (Class IIb, Level of Evidence B).
2. The routine long-term use of anticonvulsants is not recommended (Class III, Level of Evidence B) but may be considered for patients with risk factors such as prior seizure, parenchymal hematoma, infarct, or middle cerebral artery aneurysms (Class IIb, Level of Evidence B).

Management of Hyponatremia: Summary and Recommendations

1. Administration of large volumes of hypotonic fluids and intravascular volume contraction should generally be avoided after SAH (Class I, Level of Evidence B).
2. Monitoring volume status in certain patients with recent SAH using some combination of central venous pressure, pulmonary artery wedge pressure, fluid balance, and body weight is reasonable, as is treatment of volume contraction with isotonic fluids (Class IIa, Level of Evidence B).
3. The use of fludrocortisone acetate and hypertonic saline is reasonable for correcting hyponatremia (Class IIa, Level of Evidence B).
4. In some instances, it may be reasonable to reduce fluid administration to maintain a euvolemic state (Class IIb, Level of Evidence B).

Definitions:

Classes of Recommendation

Class I: Conditions for which there is evidence for and/or general agreement that the procedure or treatment is useful and effective

Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment

Class IIa: The weight of evidence or opinion is in favor of the procedure or treatment

Class IIb: Usefulness/efficacy is less well established by evidence or opinion

Class III: Conditions for which there is evidence and/or general agreement that the procedure or treatment is not useful/effective and in some cases may be harmful

Levels of Evidence

Therapeutic Recommendations

Level of Evidence A: Data derived from multiple randomized clinical trials

Level of Evidence B: Data derived from a single randomized trial or nonrandomized studies

Level of Evidence C: Consensus opinion of experts

Diagnostic/Prognostic Recommendations

Level of Evidence A: Data derived from multiple prospective cohort studies using a reference standard applied by a masked evaluator

Level of Evidence B: Data derived from a single grade A study or ≥1 case-control studies or studies using a reference standard applied by an unmasked evaluator

Level of Evidence C: Consensus opinion of experts

Applying Classification of Recommendations and Level of Evidence

*Data available from clinical trials or registries about the usefulness/efficacy in different subpopulations, such as gender, age, history of diabetes, history of prior myocardial infarction, history of heart failure, and prior aspirin use. A recommendation with Level of Evidence B or C does not imply that the recommendation is weak. Many important clinical questions addressed in the guidelines do not lend themselves to clinical trials. Even though randomized trials are not available, there may be a very clear clinical consensus that a particular test or therapy is useful or effective.

Note: In 2003, the American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines developed a list of suggested phrases to use when writing recommendations. All guideline recommendations have been written in full sentences that express a complete thought, such that a recommendation, even if separated and presented apart from the rest of the document (including headings above sets of recommendations), would still convey the full intent of the recommendation. It is hoped that this will increase readers' comprehension of the guidelines and will allow queries at the individual recommendation level. (See Table 3 in the original guideline document for a list of suggested phrases for writing recommendations.)

None provided

The type of supporting evidence is identified and graded for each recommendation (see the "Major Recommendations" field).

These recommendations are intended to summarize the best available evidence for treatment of patients with aneurysmal subarachnoid hemorrhage (SAH) and to identify areas of future research. Treatments for specific patients need to be individualized.

An implementation strategy was not provided.

Not applicable: The guideline was not adapted from another source.

American Heart Association

The Special Writing Group of the Stroke Council, American Heart Association

Writing Group: Joshua B. Bederson, MD, Chair; E. Sander Connolly, Jr, MD, FAHA, Vice-Chair; H. Hunt Batjer, MD; Ralph G. Dacey, MD, FAHA; Jacques E. Dion, MD, FRCPC; Michael N. Diringer, MD, FAHA; John E. Duldner, Jr, MD, MS; Robert E. Harbaugh, MD, FAHA; Aman B. Patel, MD; Robert H. Rosenwasser, MD, FAHA

Reviewers: Gavin Britz, Gary Ross Duckwiler, Randall Higashida, R.L. Macdonald, Adnan Qureshi

The American Heart Association makes every effort to avoid any actual or potential conflicts of interest that may arise as a result of an outside relationship or a personal, professional, or business interest of a member of the writing panel. Specifically, all members of the writing group are required to complete and submit a Disclosure Questionnaire showing all such relationships that might be perceived as real or potential conflicts of interest.

This table represents the relationships of writing group members that may be perceived as actual or reasonably perceived conflicts of interest as reported on the Disclosure Questionnaire, which all members of the writing group are required to complete and submit. A relationship is considered to be "significant" if (1) the person receives $10,000 or more during any 12-month period, or 5% or more of the person's gross income; or (2) the person owns 5% or more of the voting stock or share of the entity, or owns $10,000 or more of the fair market value of the entity. A relationship is considered to be "modest" if it is less than "significant" under the preceding definition.

*Modest
**Significant

See the original guideline document for reviewer disclosures.

This is the current release of the guideline.

Electronic copies: Available from the American Heart Association Web site .

Print copies: Available from the American Heart Association, Public Information, 7272 Greenville Ave, Dallas, TX 75231-4596; Phone: 800-242-8721

None available

None available

This summary was completed by ECRI Institute on June 30, 2010.

Copyright to the original guideline is owned by the American Heart Association, Inc. (AHA). Reproduction of the AHA Guideline without permission is prohibited. Single reprint is available by calling 800-242-8721 (US only) or writing the American Heart Association, Public Information, 7272 Greenville Ave., Dallas, TX 75231-4596. Ask for reprint No. 71-0276. To purchase additional reprints: up to 999 copies, call 800-611-6083 (US only) or fax 413-665-2671; 1000 or more copies, call 410-528-4121, fax 410-528-4264, or email kgray@lww.com. To make photocopies for personal or educational use, call the Copyright Clearance Center, 978-750-8400.