Significant advancements have been made in the prevention and treatment of acute brain attack over the past few decades. Nevertheless, stroke is still the third leading cause of death and disability in the U.S., largely because healthcare facilities have not been able to bring these advancements to the bedside in a timely manner.
Recognizing the scope of the problem and the need for integrated systems of stroke care, the Brain Attack Coalition (BAC) developed guidelines in 2000 for stabilizing and treating acute stroke patients in primary stroke centers.
The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) and several states, including Florida, Massachusetts, and New York, have since created certification programs for these centers.
The BAC also established guidelines for comprehensive stroke centers to care for stroke patients who need highly intensive medical or surgical care, specialized diagnostic tests, and interventional procedures.
Guidelines from the BAC, scientific papers, JCAHO, and state certification programs provide an overall framework for creating a stroke center. But the rush to adopt them by individual hospitals may be interfering with the common underlying principle of stroke care: rapid evaluation of the acute stroke patient.
Of 79 hospitals in the state of Massachusetts, 77 are stroke centers. The practical result is that ambulance teams send every stroke patient to the nearest stroke center, which in some cases is a 50-bed hospital that is not equipped to deal with a major stroke, said R. Gilberto Gonzalez, MD, PhD, chief of neuroradiology at Massachusetts General Hospital and a professor of radiology at Harvard Medical School in Boston.
"Efforts to make every hospital a stroke center are misguided, because you can't have a full capacity to treat major strokes, which involves an interventional team, at every 50-bed hospital. Although 50-bed hospitals can get the scans and give tissue plasminogen activator within 3 hours, there's no point in giving the drug to someone with a large-vessel occlusion because the odds of helping that individual with tPA are very low. So you end up wasting time," he said.
Gonzalez believes there should be a triage system that immediately transports patients with signs of a major stroke (such as dysphagia, paralysis, or unconsciousness) to comprehensive stroke centers and sends patients with subtle presentations of a minor peripheral stroke to a primary stroke center.
"Triage in the field will be critical," he said. "You don't want your major hospitals to get every transient ischemic attack. You also don't want to make all 5000 hospitals in the country stroke centers, because the maximum number of stroke patients who are ever going to be treated is on the order of 16% to 17%, and a quarter of those will have a major stroke that is not helped by tPA."
Would there be enough comprehensive stroke centers to handle the major strokes?
"There are 700,000 ischemic strokes a year, and about 100,000 or 150,000 are major ones. If you split them up between 300 hospitals around the country, each hospital would treat around 500 a year, which is 2 or 3 a day," Gonzalez said. "Hospitals like Northwestern Memorial in Chicago and Mass General in Boston handle 4 or 5 myocardial infarctions a day, so 2 or 3 strokes would not be a huge number."
DEVELOPING STROKE CENTERS
While guidelines and certification programs are helpful as generalized roadmaps, nascent stroke centers still need to put the recommendations together in a format that works for them. Hospitals differ widely in their personnel makeup, organizational structure, and logistics, according to Irene Katzan, MD, MS, an associate professor of neurology at The Cleveland Clinic.
Stroke centers face certain common issues:
- Staffing. In many hospitals, a stroke center is not a particular site with dedicated staff but is a service with a multidisciplinary team of on-call professionals. It begins with the emergency department and includes radiology, neurology, interventional therapy or surgery, inpatient and outpatient rehabilitation, and even wellness care to manage patients across a continuum, said Mike Harrington, COO of Sarasota Memorial Hospital. Sarasota Memorial, an 800-bed public hospital in northwest Florida that operates both a primary and a comprehensive stroke center, takes a case management approach, mobilizing stroke team members as directed by the neurologist on call and individual patients' needs.
The primary stroke center at Cleveland Clinic follows a similar scheme. The center does not have a dedicated staff, but it does have a team of clinicians involved in the management of stroke patients. The team includes vascular neurologists, critical care neurologists, endovascular neurologists, cerebrovascular neurosurgeons, inpatient neuroscience nurses, and nurses who work in the outpatient setting. The team also includes staff from transport to speech therapy, as well as nutritional care.
In contrast, the Greater Baltimore Medical Center localizes patients on 2 specific units: telemetry for less critical patients and the critical care unit for those more gravely affected. Staffing is organized in a core center that pulls together all the service units and puts resources behind them under the direction of a nurse stroke program manager, said former administrator Robert West.
- Technology. "Technology is relevant only as it pertains to the speediness of hyperacute evaluations," Katzan said.
A CT scanner that is available at all times and quick laboratory turnaround are the diagnostic cornerstones of Cleveland Clinic's primary stroke center.
Because CT must be performed before tPA can be administered-and time is of the essence-Greater Baltimore and other primary stroke centers have streamlined imaging triage processes. They maintain round-the-clock, year-round direct access to a neurology consultant who can evaluate scans to be sure a patient isn't experiencing intracranial hemorrhage, West said.
As a comprehensive stroke center, University Hospital's Neurological Institute of New Jersey in Newark offers advanced diagnostic procedures to find vascular conditions such as carotid stenosis and cerebral aneurysms. In addition to CT and MRI, University Hospital provides blood flow tests, carotid and transcranial Doppler ultrasonography, and cerebral CT and MR angiography.
- Safety. One focus of a primary stroke center is to rapidly evaluate acute stroke patients and either administer tPA immediately or stabilize and transfer a patient to a hospital that can provide other forms of treatment. But it is not the only focus, Katzan said.
"Once you get over the 3 to 6-hour window, the management that's relevant to 99% of stroke patients occurs. It involves good systems of care, like the prevention of complications, good nutritional therapy, screening for dysphasia and deep venous thrombosis, and the initiation of intrathrombotic agents. All those processes have to be in place in a widespread and systematic way to improve the outcomes of patients," she said.
Sarasota Memorial recently opened the Institute for Advanced Medicine with a comprehensive neurological rehabilitation service and wellness center.
"That's what this whole program in neuroscience is built around: helping patients gain and maintain as much quality of life as possible with this kind of illness," Harrington said.
- Communication. Patient and physician education is the best way the medical community and the community at large can help ensure that stroke patients get rapid access to a hospital where they can receive life-saving interventions, Katzan said.
Primary and comprehensive stroke centers are using billboards, direct mail, and television announcements to let the public know about the importance of getting to a hospital quickly if they note signs of a stroke and about the services hospital stroke centers can provide.
The stroke program manager at Greater Baltimore Medical Center also visits physicians' offices and sends out mass communications as part of the center's marketing and public relations programs, West said.
Sarasota Memorial conducts symposia and educational presentations for physicians and emergency medical technologists on a grassroots, one-on-one basis, Harrington said.
IMAGING TECHNOLOGY
More complex imaging consequently is becoming a critical service at stroke centers, especially for patients who are likely to have had a major ischemic stroke or a transient ischemic attack that may require immediate treatment to forestall a major stroke.
In the overall evaluation of stroke patients, multislice CT evaluates the presence and extent of hemorrhage in a matter of seconds. By mapping the cerebral blood volume, CT angiography can pinpoint the area of infarction and indicate the amount of tissue at risk for further infarction. Dynamic CT perfusion of the tissue at risk can distinguish dead from viable tissue, said Richard Latchaw, MD, a professor of radiology and chief of neuroradiology and interventional radiology at the University of California, Davis.
MRI provides a diffusion-weighted image that is the most sensitive way of detecting acute ischemia. MRI tends to be easier to interpret than CT. MRI also covers the entire brain in perfusion studies, while CT typically captures between 2 cm and 4 cm of brain tissue and therefore can miss lesions outside of its range, said Howard A. Rowley, MD, chief of neuroradiology and an associate professor of radiology, neurology, and neurosurgery at the University of Wisconsin in Madison.
At the University of Wisconsin, MR images are automatically analyzed by a software package that creates perfusion parameter maps without postprocessing at the console or a stand-alone workstation. By reducing the additional offline postprocessing steps, Rowley saves at least 15 minutes per case.
The university also uses 2 imaging protocols. The standard bells and whistles "stroke deluxe" technique, which provides highly detailed images, uses fast spin-echo T1-weighted imaging. The "emergency stroke" method, which involves fast spoiled gradient-recalled (SPGR) sequences and replaces high-resolution 3D imaging of the neck with a single acquisition that looks at the blood vessels of the neck, cuts some corners but nevertheless provides perfusion, diffusion, and brain and neck MR angiography, he said.
"The big picture for both CT and MRI is the development of fast yet comprehensive protocols," Rowley said. "By fast, I mean on the order of 10 to 15 minutes for the entire study to be done. By comprehensive, I mean getting beyond the brain substance-the parenchyma itself-to also look at blood vessels with CTA or MRA and, ideally, incorporate brain perfusion studies to give a more global, comprehensive physiological assessment of what's going on with the stroke patient."
Karen Sandrick is a freelance writer based in Chicago.
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Stroke resources
Brain Attack Coalition
This site contains a variety of guidelines, orders, and pathways designed to improve timely and effective delivery of stroke care, including recommendations for establishing a stroke center.
http://www.stroke-site.org/
JCAHO Primary Stroke Center Certification
http://www.jointcommission.org/CertificationPrograms/PrimaryStrokeCenters
Recommendations for the Establishment of Stroke Systems of Care
Recommendations from the American Stroke Association's Task Force on the Development of Stroke Systems
http://stroke.ahajournals.org/cgi/content/full/36/3/690
Stroke Trials Registry
http://www.strokecenter.org/trials/
RECOMMENDED READING
- Albers GW, Thijs VN, Wechsler L, et al. Magnetic resonance imaging profiles predict clinical responses to early reperfusion: the diffusion and perfusion imaging evaluation for understanding stroke evolution (DEFUSE) study. Ann Neurol 2006;60(5):508-517.
- Chalela JA, Kidwell CS, Nentwich LM, et al. Magnetic resonance imaging and computed tomography in emergency assessment of patients with suspected acute stroke: a prospective comparison. Lancet 2007;369(9558):293-298.
- Hacke W, Albers G, Al-Rawi Y, et al. The desmoteplase in acute ischemic stroke trial (DIAS): A phase II MRI-based 9-hour window acute stroke thrombolysis trial with intravenous desmoteplase. Stroke 2005;36:66-73.
- Kidwell CS, Chalela JA, Saver JL, et al. Comparison of MRI and CT for detection of acute intracerebral hemorrhage. JAMA 2004;292(15):1823-1830.
- Kidwell CS, Jahan R, Starkman S, et al. MR and recanalization of stroke clots using embolectomy (MR-RESCUE). Presented at the American Stroke Association International Stroke Conference, Feb. 16, 2006, Kissimmee, FL.
