Each year in the United States, nearly 800,000 people suffer a stroke, or a brain attack. This occurs when an artery that supplies blood to part of the brain becomes blocked or ruptures and leads to bleeding in the brain. In ischemic strokes, a blood clot is the triggering event, while the remaining 10 percent of strokes are called hemorrhagic and a burst blood vessel or aneurysm is typically the cause.
Strokes occur frequently: Once every 40 seconds, while every four minutes an American dies from stroke complications. Stroke is now the fourth leading cause of death in this country—and number one in much of the world. Although many people survive a stroke, even multiple episodes, stroke is still the number one cause of disability.
Stroke has profound impact on health. When blood flow is interrupted to a portion of the brain, the brain’s neurons become starved of the nutrients and oxygen needed to function properly. Within minutes, damage—sometimes-irreversible destruction—occurs. After a few hours of disrupted blood flow, neurons begin to die off, and brain function is lost.
The consequences of stroke can be devastating: Nerve cell damage due to a stroke is often permanent, leading to such impairments as difficulty walking, speaking, and thinking.
With the FDA approval in 1996 of the emergency stroke drug, tissue-type plasminogen activator, or r-tPA, doctors finally had a treatment for ischemic stroke—the most prevalent kind—that could effectively break up a blood clot that was hindering blood flow to the brain. With the clot dissolved, blood flow resumes, brain injury is minimized, and the risk of permanent disability decreased. The chance of getting better without tPA is almost zero.
Time lost is brain lost and every second counts for stroke victims: Each minute that goes by, it’s estimated that two million brain cells die. The faster t-PA is given after a stroke, the more effective and safer it is. Best given within an hour of arrival at a hospital, the intravenous drug may still be used in select patients up to 4.5 hours from symptom onset. The problem is that only 2 to 7 percent of people eligible for tPA ever get the clot-busting drug in this country.
In order to improve stroke outcomes, a few hospitals in Germany and the United States are now using specially equipped mobile stroke treatment ambulances outfitted with all the necessary elements for the emergency evaluation and treatment of stroke and taking them on the road—bringing the highest level of care directly to the patient.
These high-tech ambulances, with onboard paramedic, critical care nurse, EMT, CT technologist, and virtual stroke neurologist (via telemedicine) are now bringing the emergency department straight to the patient with stroke symptoms—wherever he or she may be.
The goal is to preserve optimal brain function by performing a neurological evaluation, making an accurate diagnosis and administering tPA as soon as possible, occasionally as fast as 11 minutes after arrival on the scene. This prevents and often reverses the effects of stroke before they can lead to permanent brain injury.
The faster an ischemic stroke is recognized, the faster effective treatment can be administered. With the mobile stroke treatment unit, a special portable computed tomography (CT) scanner takes brain images in two minutes, which are then rapidly sent via a 4G broadband wireless link to hospital neurologists and neuroradiologists to interpret and yield a diagnosis. These doctors then prescribe and direct the treatment of the patient via the video hookup, and then triage the patient based on stroke type and severity to the appropriate hospital resource in the area.
After an ischemic stroke is detected, tPA therapy begins immediately in the ambulance, well before arrival at the hospital, dramatically cutting the time from diagnosis to treatment. Thanks to the mobile stroke unit, many survivors recover fully and regain their previous levels of function.
Where Are They Now
Mobile stroke treatment units have been in use in Ohio and Texas for over a year now, and have shown significant improvements in stroke treatment times. Studies examining patients who use the mobile stroke unit found that CT scans were accomplished 20 minutes sooner and the total treatment time was significantly reduced from an average of 104 minutes in the emergency room to 64 minutes. There is an ongoing study to determine the cost-effectiveness of this treatment option.