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 and control 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.