Mobile stroke units debuted in two U.S. cities during the past year, and already they are saving critical minutes when it comes to treating stroke patients, according to a pair of studies released Wednesday.
The mobile units, each of which resemble an ordinary ambulance and cost about $1 million, are essentially specialized emergency rooms on wheels. They include unique equipment, such as a portable CT scanner to help determine what type of stroke a patient is experiencing and how best to treat it. They also include lab testing equipment and clot-busting drugs that can greatly improve the prognosis for patients who receive them soon after the onset of symptoms. In addition, the units are staffed with a critical care nurse and a paramedic, as well as a CT technology expert. In Cleveland, where one of the units began last summer, two-way video conferencing also allows a doctor to remotely evaluate a patient.
"This is a situation where every minute counts," said M. Shazam Hussain, head of the stroke program at the Cleveland Clinic, which recently named the mobile unit as a top medical innovation for 2015. "Time is critically important. You lose something like 2 million brain cells a minute [during a stroke]."
Researchers in Cleveland, where the stroke unit operates from 8 a.m. to 8 p.m. each day, examined the cases of dozens of patients treated by the mobile unit vs. those who went to the emergency room. They found that, on average, patients received a CT scan more than 20 minutes faster when using the mobile stroke unit. They also noted a "significant reduction" in treatment time -- 64 minutes when the mobile unit responded versus 104 minutes in the emergency room.
Hussain said Wednesday that while researchers are still investigating whether the faster response times translate directly into positive outcomes for patients, it is well established in the medical world that the sooner stroke patients receive treatment, the better off they typically are.
"Every 15 minutes you can save, you're probably improving their outcome by twofold," Hussain said. "It could make the difference between someone surviving a stroke or not surviving a stroke. Or being fully disabled or not."
In 2012, a study involving 100 patients in Germany also found that mobile stroke units there led to quicker diagnosis and more rapid administration of clot-busting drugs. Experts then argued that larger studies were needed to determine whether the faster response times led to better overall outcomes, and whether mobile units would be feasible only in densely populated urban areas, or also in more rural locations.
The first mobile stroke unit in the United States began operating last spring in Houston, where officials from the University of Texas Health Science Center outfitted a donated ambulance with a CT scanner and other equipment and staffed the vehicle a neurologist and a registered nurse with stroke expertise, among other emergency workers. The unit responds to possible stroke cases within a several-mile radius of the Texas Medical Center in Houston. Here's a video describing how it works:
A key goal was to try to treat ischemic strokes, the most prevalent type, with the clot-busting drug tPA as soon as possible after the first symptoms appear. So far, the mobile unit seems to be succeeding on that front in a significant number of cases.
"Despite two decades of efforts to streamline systems of care, most patients are treated beyond the two hours when tPA is most effective," Stephanie Parker, a project manager of the UTHealth Mobile Stroke Unit in Houston, said in a statement Wednesday detailing the findings. "Our ultimate goal is to show that patients treated on the mobile stroke unit will have better outcomes because of earlier treatment and, therefore, will have fewer long-term acute care needs and/or rehabilitation needs."
Stroke, which occurs when the blood flow to the brain is hindered by a blockage or a rupture in an artery, is the fourth leading cause of death in the United States and a major cause of long-term disability, according to the Centers for Disease Control and Prevention. An estimated 800,000 Americans suffer from a stroke each year.