New Guidelines on Management of Aneurysmal Subarachnoid Hemorrhage

Susan Jeffrey

January 22, 2009

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January 22, 2009 — New guidelines on the management of aneurysmal subarachnoid hemorrhage (aSAH) have been released by the American Heart Association/American Stroke Association.

Among recommendations based on newly available evidence are that these patients be treated at high-volume centers where endovascular interventions as well as neurosurgical services are available. Guideline authors also caution that despite having generally among the most dramatic presentations in medicine, these hemorrhages can present as a milder sentinel headache, and aSAH should be considered in the differential diagnosis of all patients with new headache.

Joshua B. Bederson MD, professor and chair of the department of neurosurgery at Mount Sinai Medical Center, in New York, and chair of the writing group for the new guidelines, told Medscape Neurology & Neurosurgery that aSAH is a complex process, from the initial bleed to the devastating delayed effects of rupture.

"What has changed over the past 15 or 16 years is a gradual improvement in understanding of many of the separate processes that constitute the disease, as well as the evolution of some new technologies such as endovascular treatment of aneurysms that were really just beginning at the time of the first guidelines," Dr. Bederson said in an interview.

The guidelines are published online January 22 in Stroke.

Improving Outcomes by Many Paths

Mortality associated with aSAH is high, about 45% in the first 30 days after a rupture, Dr. Bederson said. Still, he notes, "The majority of aneurysms do not rupture, and as much as 1% of the population dies of old age with a small, unruptured aneurysm."

When they do rupture, the focus of treatment has to be on both prevention of rebleeding and management of the pathological adverse effects that the bleed has in the brain. However, he said, "We still have very few treatments for the hit that the brain takes during the first seconds after the hemorrhage. Most of our progress has been in secondary things like preventing the aneurysm from rebleeding, which can occur in 20% of patients in the first 2 weeks."

The last guidelines document was released in 1994, and 1 of the main changes since then has been the development of endovascular approaches to obliteration of aneurysms. Development since that time of the subspecialty of neurocritical care, with its own fellowships and certification, may also have improved outcomes, Dr. Bederson noted.

"The current standard of practice calls for microsurgical clipping or endovascular coiling of the aneurysm neck whenever possible," the writing group concludes. "Treatment morbidity is determined by numerous factors, including patient, aneurysm, and institutional factors. Favorable outcomes are more likely in institutions that treat high volumes of patients with SAH, in institutions that offer endovascular services, and in selected patients whose aneurysms are coiled rather than clipped."

Other major conclusions in the new guidelines include:

  • SAH is frequently misdiagnosed, in up to 12% of cases. For the initial evaluation of headache, CT scanning for suspected SAH is "strongly recommended," followed by lumbar puncture if the CT is negative. A standard management protocol for the evaluation of patients with headaches and other symptoms that may potentially relate to SAH does not currently exist and should be developed.

  • Early vs later treatment of the aneurysm reduces the risk for rebleeding after SAH, and so early surgery is "reasonable and probably indicated in the majority of cases," the authors write.

  • Medical measures to prevent rebleeding include blood-pressure monitoring andcontrol and bed rest, although these should be part of a broader strategy with more definitive measures. A short course of antifibrinolytics may be considered prior to definitive treatment.

  • To reduce poor outcomes associated with vasospasm, the authors "strongly recommend" use of oral nimodipine. The value of other calcium antagonists remains uncertain, they note. Treatment begins with early management of the ruptured aneurysm, they add; "in most cases maintaining normal circulating blood volume and avoiding hypovolemia is probably indicated."

  • Another "reasonable" approach to symptomatic vasospasm is volume expansion with induction of hypertension and hemodilution, so-called "triple-H therapy," the authors note. "Alternatively, cerebral angioplasty and/or selective intra-arterial vasodilator therapy may also be reasonable, either following, or together with, or in the place of, triple-H therapy, depending on the clinical scenario."

  • The relationship between hypertension and aSAH is "uncertain," they conclude, but management of blood pressure to prevent other clinical problems is recommended. Quitting smoking is "reasonable," they note, "although the evidence for this association is indirect."

  • Screening for unruptured aneurysms in high-risk populations is of "uncertain value," they conclude. Noninvasive imaging may be used for such screening, "but catheter angiography remains the 'gold standard' when it is clinically imperative to know if an aneurysm exists."

Other recommendations in the document focus on the management of hydrocephalus, hyponatremia, and volume contractions, as well as seizures.

The management of aSAH is so complex that "people have really been clamoring for recommendations or guidelines," Dr. Bederson said. The final document is large, with over 85 pages and more than 400 references, but basically summarizes the current literature into recommendations on each of the complex processes that run their separate course after aSAH.

"Even if there isn't 1 major new earthshaking change, putting it all together for the practitioner may be the most valuable part of this," he said.

Dr. Bederson reports he has no conflicts of interest. Disclosures for other members of the writing group appear in the paper.

Stroke. Published online January 22, 2009.