The Rapid Evolution of Stroke Care
MADISON - With stroke, time is brain.
Eighty-five percent of the 700,000 strokes that occur nationally each year are ischemic, wherein a blood clot moves to the brain and interrupts the flow of blood. For each minute that passes, an estimated two million brain cells die, and every second diminishes the stroke sufferer's chance to return to normal function.
The rapid evolution of stroke treatment over the past 10 years has been geared toward attacking blood clots and addressing symptoms as quickly as possible, and advances in drug treatments have been complemented by an expansion of the role stroke nurses play in assessment, treatment and follow-up.
"Truly a light bulb moment"
Before 1996, medical intervention for stroke patients was after-the-fact. A stroke occurred, and a rehabilitation team helped the patient deal with its aftermath.
"If people had strokes, they were not a priority for ambulance transport, nor were they a priority in the emergency room," says Karen Jankowski, MS RN, Clinical Nurse Specialist, manager of the Stroke Clinic at UW Hospital. "The perception was, 'There is nothing we can do.' "
That all changed with the Food and Drug Administration's 1996 approval of tissue plasminogen activator (t-PA), which can dissolve the blood clots that catalyze ischemic stroke.
"t-PA was truly a light bulb moment in terms of having something we could do," Jankowski says. "Physicians had a way to stop a stroke that's in progress. If we can break up that clot and reestablish blood flow, we can save those brain neurons."
Although t-PA was a major breakthrough, it is not a panacea. It sometimes causes bleeding in the brain, which disqualifies it as a treatment for hemorrhagic stroke, and must be administered within three hours of initial symptom onset.
This second factor disqualifies all but 4 percent of ischemic stroke patients from receiving t-PA. Most patients just don't get to the emergency room quickly enough to reap the drug's benefits.
"In that three hours the walls of the blood vessels are deteriorating, and you can turn the ischemic stroke into a bleeding stroke (by using t-PA)," says Jankowski. "There's a need for a drug that widens that window."
Which is exactly the goal toward which the University of Wisconsin's clinical trials research is pointing.
The vampire bat's place in stroke care
Desmoteplase, a manufactured protein originally discovered in the saliva of vampire bats, is the focus of one of four UW clinical trials involving stroke patients. As acute stroke study coordinator, Kathy Acher, BSRN, CCRC, is responsible for enrolling eligible patients into the appropriate trial. She says that patients almost always opt for the clinical trial treatment if they qualify.
"Almost everyone says yes," she says. "They say, 'Do everything you can do.' "
(Not all clinical trial participants receive desmoteplase. Like many clinical trials, the desmoteplase study is double-blind and dose-ranging, which means one of every three subjects receive a placebo. And Acher stresses that while the drug is promising, it has not yet been approved by the FDA and thus its full effect has not yet been determined.)
Why so willing? In the case of desmoteplase, the treatment window is nine hours - six hours longer than that of t-PA - and the side effects few. In short, desmoteplase potentially offers a better chance at recovery for a larger segment of the stroke population, and the UW Hospital emergency room is the only place in Wisconsin where it's available.
"We offer cutting-edge therapies as clinical trials that aren't available elsewhere," Acher says. "Stroke is now an acutely managed event and the clinical trial may affect the outcome and improve their chances."
Still, only a few people per month are enrolled in the desmoteplase trial because of the extensive list of inclusion and exclusion criteria each enrollee must meet.
"It's based on the condition they're in to start with - we don't enter anybody in a trial who isn't totally functional prior to the stroke," says Acher. "About 30 strokes come in here each month. We're lucky if we enroll one or two, because most people don't qualify."
Drug discoveries may be the most dramatic advances in the treatment of stroke, but they're not the only factors in improved care. The role of nurses in early stroke intervention has expanded, as well, and plays a key role in mitigating a stroke's debilitating effects.
"From the nursing perspective, there are a lot of things we can do now post-stroke," says Chris Wilson, RN, MSN, UW Health's stroke program coordinator. "There are improved outcomes with tighter glucose control. Body temperature and blood pressure management is another way. The tighter we can control it, the better the outcome the patient will have."
The emphasis on prevention is also on the rise. Stroke Clinic staff keep an exhaustive checklist of factors that increase the risk of stroke - blood pressure, lipid levels, body weight, age and smoking are a few - and provide strategies for patients to improve in areas where they need to.
"Some are uncontrollable, some are controllable," Jankowski says. "The uncontrollable ones make it more important to control the controllable ones. If you're 70 and smoking, it's even more important you stop than if you're 50."
Wilson also points to the work underway to counteract the negative psychological impact of stroke. Many stroke patients suffer from depression and anxiety stemming from the uncertainty of their physical health. Support groups like the one UW Hospital offers have proven effective in resolving stroke's negative mental ramifications.
"It's an important component to care," Wilson says. "One of the best ways to combat depression is to help people have control over their condition. They can talk about barriers to getting back into their communities and how to get back to doing the things they used to do. The group helps people get back to their lives."
Information about UW Health's stroke program is available on uwhealth.org. General information about stroke, including warning signs, frequently asked questions and an extensive stroke encyclopedia can be found on the American Stroke Association Web site.
Date Published: 08/21/2009