CHAPEL HILL -- People who think they or someone else is suffering a stroke need to call 911 to summon emergency medical service (EMS) immediately and not wait for any reason, according to two new University of North Carolina at Chapel Hill studies. That's the most effective way to take advantage of a new clot-busting drug known as tPA and possibly prevent death or permanent impairment.
The related studies, conducted at the UNC-CH schools of public health and medicine, focused on why stroke treatment often is delayed. Both appear in the November issue of Stroke, a publication of the American Heart Association.
One, titled "Second Delay in Accessing Stroke Healthcare (DASH 11) Study," looked at how patients and witnesses reacted to stroke symptoms and tracked 617 patients arriving at hospital emergency rooms in Denver, Chapel Hill, N.C. and Greenville, N.C.
Patients who used EMS had a median pre-hospital delay of 2.85 hours, compared to 4.03 hours for those who didn't use EMS, said doctoral student Emily Schroeder and her mentor, Dr. Wayne D. Rosamond, assistant professor of epidemiology. But even the 2.85-hour median elapsed time for patients using EMS is far too slow.
"It can take an hour or more to complete and interpret necessary tests like a CT scan, which have to be done before thrombolytic (clot-dissolving) therapy can be given," Schroeder said. "The time a patient takes deciding to seek care is the biggest portion of the time between onset of symptoms and treatment. Once EMS is alerted, things can happen quickly, but people don't call 911 unless they perceive their symptoms to be urgent."
Dr. Dexter L. Morris, vice chair of emergency medicine at UNC-CH, led the second study, which involved monitoring 1,207 patients diagnosed with stroke or "mini-strokes" at 48 hospital emergency rooms nationwide.
"There's a limited window of opportunity of about three hours after the onset of stroke symptoms in which the patient's outc
Contact: David Williamson
University of North Carolina at Chapel Hill