Patients experiencing an ischemic stroke, or a stroke caused by a blood clot or other blockage, can benefit greatly from receiving intravenous tissue plasminogen activator (tPA). Colloquially known as a “clot-buster,” tPA works best when administered to acute stroke victims in three hours of onset.
Despite its proven lifesaving value, emergency physicians often hesitate to prescribe tPA. If a patient is having a hemorrhagic stroke, then tPA could cause more bleeding, further brain damage, and even death. Many hospitals, even in some urban areas, have no staff to offer specialized stroke and brain imaging expertise.
For this reason, both the American Heart Association (AHA) and the American Stroke Association (ASA) have endorsed teleradiology as a crucial component of telestroke analysis. By distinguishing hemorrhagic stroke victims from ischemic stroke victims, teleradiology providers can increase the number of ischemic stroke patients that have access to intravenous tPA.
How tPA Works
When tPA is administered, it breaks a peptide bond to help plasminogen transform into plasmin, an enzyme that breaks down blood clots. Breaking down clots can restore some or all of the brain’s blood supply, minimizing the risk of brain damage and death. Currently, tPA is only administered to between 2 and 3 percent of stroke patients. After the first three hours following stroke onset, tPA is only moderately effective up to four and one-half hours after onset and not particularly effective thereafter.
The best candidates for tPA treatment score between 16 and 20 on the National Institutes of Health Stroke Scale (NIHSS). The patient should be in the verifiable time window, meaning that doctors can confirm that stroke onset occurred no more than three hours prior to tPA administration.
Doctors should see no verifiable bleeding on a CT scan, and the patient should have no history of bleeding disorders or heart attack. Finally, doctors shouldn’t administer tPA to patients who have had surgery in the past 14 days or who have suffered head trauma in the last three months.
Why Do So Few Stroke Patients Receive tPA?
Stroke is difficult to diagnose because patients can present a wide range of symptoms. Additionally, their symptoms could be caused by many different disorders. Identifying which type of stroke is taking place is virtually impossible without an imaging scan, usually a CT scan.
CT scans are good at revealing hemorrhagic stroke, but they are not always effective at pinpointing a clot. If the doctor interpreting the CT scan is not a stroke expert, he or she may have difficulty drawing conclusions from the image.
Since ischemic strokes comprise 80 percent of all strokes, far too few patients are receiving tPA treatment. Most likely, ER physicians hesitate to administer tPA because of fear of inappropriate patient selection, fear of complications, and fear of incorrectly documenting the onset of stroke.
The AHA/ASA recommends a combination of telemedicine and teleradiology when asking for offsite stroke specialist reviews. With these combined technologies, specialists can both visually review patients and examine patient imaging scans.
Telemedicine and Teleradiology: A 1-2 Punch for Stroke Diagnosis
Telemedicine via high-quality video teleconferencing (HQ-VTC) has been used by hospitals so that remote stroke specialists could administer the NIHSS. Administering the NIHSS over a video connection, according to AHA/ASA reviews, is comparable to having an expert administer the NIHSS by a patient’s bedside.
To an HQ-VTC consult, the AHA/ASA recommends adding a real-time imaging scan sent via an FDA-approved teleradiology system.
Unfortunately, acute care facilities often foot the bill for obtaining telemedicine and teleradiology systems. When these facilities are in rural areas or poor urban areas, the financial benefits of reduced disability and reduced rehabilitation time from tPA administration may not visibly offset the upfront technological investment.
Dr. Robert J. Adams, who administers the Remote Evaluation of Acute Ischemic Stroke at the Medical University of South Carolina (REACH MUSC), has called on state governments and insurers who do benefit from reduced disability costs to invest in developing telestroke networks in these acute care facilities.
When facilities have no access to onsite specialists, teleradiology and telemedicine investment is essential for good patient outcomes. Increasing appropriate intravenous tPA administration for ischemic stroke victims could save not only many health care dollars but also many victims’ lives.