Acting on behalf of the Phoenix Metropolitan Matrix of Primary Stroke
Centers and the Phoenix Operation Stroke Executive Committee, these physicians
developed a 24/7 stroke team led by three fellowship-trained stroke
neurologists who provided education and training to emergency physicians and
nurses. The group also made sure there was clear communication with the
radiology department and labs to enhance the expediency of necessary scans and
blood work. The goal—improving stroke team response—was achieved by observing
procedures for emergency response to other events such as acute myocardial
infarction.
"At the Mayo Clinic Hospital, when a patient arrives with acute onset
of focal neurological symptoms and signs consistent with a stroke and the time
of onset is within the past three hours, the patient is transferred to a
dedicated stroke treatment room," explained Bart Demaerschalk, MD, MSc,
FRCPC, director of the Cerebrovascular Diseases Center at the Mayo Clinic in
Scottsdale, Ariz., and one of the project's leaders. "The emergency
physician and stroke neurologist are notified, two [intravenous (I.V.)] sites
are established, blood tests are sent, and a stat computed tomography [CT] is
obtained. The stroke neurologist assesses the patient and decides whether to
administer thrombolytic therapy."
In 2003, the t-PA team posted algorithms and time targets for these steps in
the emergency department. They included paging the stroke neurologist within 10
minutes of a patient's arrival in the emergency department, performing a CT
scan within 25 minutes and administering t-PA within 60 minutes. A review of 60
patients—30 treated before the algorithms were posted and 30 afterward—revealed
definite decreases in time from patient arrival to notification of the stroke
neurologist (22 vs. 5 minutes; P<0.001), to CT scan (34 vs. 24
minutes; P<0.005) and to t-PA treatment (81 vs. 66 minutes; P<0.001).
"These improvements in times are statistically significant. When there
is brain ischemia in the setting of an acute stroke, every minute counts,"
Dr. Demaerschalk observed.
But there is still room for improvement; the American Stroke Association
recommends a time lag of 35 minutes from CT to t-PA, and the
Furthermore, "not every patient with ischemic stroke will be eligible
for t-PA," Dr. Demaerschalk said. "There is a ceiling effect of 20%
to 30%, which is limited by the t-PA exclusion criteria. For example, if a
patient wakes up from a night's sleep with stroke symptoms, t-PA cannot be
administered, because the time of symptom onset cannot be identified."
In many communities, acute t-PA stroke treatment programs have been slow to
develop, partly because of the staff requirements, and partly because of a
perceived marginal benefit of t-PA among some neurologists. More importantly,
perhaps, the extra time required by hospital personnel also has not been
reimbursed—until now. A new diagnosis-related group (DRG) that recognizes the
increased intensity of care required by an acute t-PA program was recently established
to provide an additional $6,000 to a hospital when a patient receives t-PA.
This DRG, plus the increasing acceptance of the value of t-PA by community
physicians, may help increase the numbers of patients treated within the
three-hour window.
Another new approach is being taken by Ben Bobrow, MD, a physician in the
Mayo Clinic's Department of Emergency Medicine and medical director of the
Bureau of Emergency Medical Services, a division of the Arizona Department of
Health Services, and the other leader of the t-PA team. Dr. Bobrow works
closely with emergency medical responders outside the hospital, like
firefighters and emergency medical technicians. "An aspect of improving
the time to t-PA and stroke outcomes requires the education of the public to rapidly
recognize stroke symptoms and to immediately call 911. Emergency medical
services need to consistently deliver patients to the nearest stroke
center," he said.
Drs. Demaerschalk and Bobrow discussed their program at the 2005 annual
meeting of the American Neurological Association.
—Andrew N. Wilner, MD, FAAN, FACP
Comment From the Field
Blood pressure lowering has a dramatic effect on stroke risk overall.
Patients with atrial fibrillation are at higher risk of stroke, and a large
proportion of these are unrelated to the atrial fibrillation. I suspect that
the impact of perindopril in this population is primarily related to reduction
of risk for these noncardioembolic strokes.
—S. Claiborne Johnston, MD, PhD
Associate professor of neurology and epidemiology and director of Stroke
Service at the University of California at San Francisco School of Medicine