Although thrombolysis with alteplase is an effective therapy for ischemic stroke, few patients arrive at the hospital in the three to 4.5 hour time window required for use. Improved prehospital processes are essential to offering the therapy to additional patients with stroke, according to a review published in the June issue of Lancet Neurology.
Thrombolysis with alteplase is administered to only 1 to 8 percent of stroke patients, partially due to delays in prehospital management, according to Klaus Fassbender, MD, of University Hospital of the Saarland in Homburg, Germany, and colleagues. In addition, within this “golden window,” treatment benefits decrease with time.
Fassbender and colleagues offered an array of prehospital patient management strategies to help increase the number of patients who arrive at the hospital within the time window for alteplase administration.
Research has indicated that between 24 and 54 percent of patients do not call for help within the first hour of stroke onset. Other evidence has pointed to the importance of emergency medical services (EMS) rather than personal transport; that is, EMS transport is a strong predictor of arrival within two hours of symptom onset.
Although conventional wisdom suggests patient stroke education campaigns may play a role, most have been more effective at raising awareness than changing behavior, according to Fassbender et al. “[An] obvious challenge is overcoming the gap between knowledge about stroke and appropriate behavior in the emergency situation.”
EMS can be leveraged to optimize stroke management, and several strategies have been demonstrated to be effective. These include educational programs for EMS personnel, use of instruments for symptom recognition, priority transport to centers with stroke experience and algorithms for advanced notification of receiving hospitals.
The correct identification of stroke by EMS dispatchers ranges from 30 to 83 percent, which suggests the need for continuing education that includes medical training, education about instruments to recognize stroke, the importance of priority transfer to experienced stroke centers and prenotification of centers.
Fassbender and colleagues recommended EMS dispatchers use the Medical Priority Dispatcher Systems stroke protocol or Cincinnati prehospital stroke scale, as well as the face arm speech time (FAST) scale, which can be used by community members.
“Although the use of such scales still represents a compromise between accuracy in the recognition of more complex deficits and practicability in critical emergency situations, their application is an important step in the right direction.”
Dispatch to hospitals with stroke expertise can up alteplase administration from 10 percent to 24 percent, according to the authors. Fassbender et al noted the evolving nature of guidelines, which currently recommend transport to the closest hospital that provides emergency stroke care. As other therapies, such as mechanical recanalization, are employed, patients may need to be diverted to specialized centers that offer this treatment.
Prenotification of the receiving hospital allows staff to prepare imaging equipment and other resources and can reduce door-to-imaging times and door-to-needle times, while enabling shorter symptom-onset-to-needle times and a greater likelihood of treatment with alteplase within three hours.
The authors also previewed potential future developments. These include equipping ambulances with diagnostic and therapeutic tools, use of telemedicine-based communication between EMS and hospital personnel and prehospital stroke treatment at the emergency site.
“[Every] link in the prehospital stroke rescue chain matters and must be further studied for potential improvements,” the authors concluded.