By Tracey Barron
FAST is key to effective stroke identification and treatment.
FAST is the acronym for warning signs, and FAST is the speed of action required to improve the chances of patient survival.
FAST is also the outcome reached in research assessing the effectiveness of EMD use of the telephone-administered Stroke Diagnostic Tool (SDxT) in emergency calls.
FAST—the acronym
A stroke occurs when one of the arteries to the brain is blocked (ischemic) or bursts (hemorrhagic). When that happens, the area of the brain affected starts to die. The damage can cause problems with walking, speaking, seeing, or feeling.1
Stroke and cerebrovascular disease are the second largest cause of death in the world.2 A stroke can occur at any age; risk of a stroke more than doubles each decade after age 55.
The U.S. National Stroke Association presents the acronym FAST to remember the warning signs of a stroke:3
F—is for Face: Ask the person to smile. Does one side of the face droop?
A—is for Arms: Ask the person to raise both arms. Does one arm drift downward?
S—is for Speech: Ask the person to repeat a simple phrase. Is his or her speech slurred or strange?
T—is for Time: If you observe any of these signs, call 9-1-1 immediately.
The Medical Priority Dispatch System (MPDS) Stroke Diagnostic Tool (SDxT) involves a quick, three-item diagnostic test—asking the patient to smile (to check for facial drooping), asking the patient to raise both arms above his/her head (to check for weakness or paralysis on one side of the body), and asking the patient to repeat “The early bird catches the worm” (to identify any speech abnormalities). Each question is scored, according to the patient’s response. The higher the score, the higher the likelihood of evidence of a stroke.
FAST—speed of action
When a person suffers a stroke, prompt treatment can mean the difference between permanent neurological damage and an almost-full recovery; treatment is most effective when administered as soon as possible after onset.4 When a stroke is suspected, a call for emergency medical help is paramount.
Protocol 28: Stroke (CVA)/Transient Ischemic Attack (TIA) in the MPDS is selected for the conscious and breathing patient when the caller initially reports “stroke” or one or more of the symptoms listed in the STROKE Symptoms list on Protocol 28. Since it is impossible in a prehospital environment to tell whether symptoms are from a TIA—a temporary disruption in the blood supply to part of the brain—or an acute stroke, EMDs should assume that all stroke-like symptoms signal an emergency and need prompt evaluation.
SDxT—methods
The University of North Carolina, School of Medicine, Department of Emergency Medicine, published a study5 to assess the effect of introducing telephone-administered SDxT into stroke-related 9-1-1 calls to the Raleigh-Wake County (N.C.) communication center. Dispatchers were trained in using the SDxT and administer the tool when using Protocol 28.
Study participants were divided into two groups: callers identified by 9-1-1 dispatchers as reporting stroke-like symptoms (forward-identified), and stroke patients transported by Wake County EMS and discharged from the hospital with a diagnosis of stroke (considered true strokes) (reverse-identified).
Data was collected from calls received from May 1, 2007, to June 30, 2008—divided into “before” (n= 41,088) and “after” (n=34,627) use of the SDxT.
Dispatcher accuracy (after—during the period they were using the SDxT) was compared to the accuracy that would have been obtained had the SDxT been used as the screening instrument for sensitivity and specificity (before—during the period prior to using the SDxT), based on the caller complaints leading to protocol selection.
SDxT—results
The percent of true stroke patients identified increased by 5% after the SDxT was used, compared to pre-implementation. The sensitivity and specificity of stroke identification before and after SDxT implementation was similar, however the accuracy by which patients with stroke-like symptoms were dispatched increased by almost 5%.
The most common non-stroke dispatch categories among reverse-identified patients—those the EMD did not categorize as stroke patients before or after the tool was introduced—included unconscious, sick person, and fall. This finding was one of the most relevant in the evolution of the SDxT.
These results raise the possibility of integrating the SDxT into these additional Chief Complaints in the MPDS. In fact, the SDxT is currently being added to Protocol 18: Headache in v13.0 of the MPDS.
Placement of the SDxT in protocols relevant to possible stroke—for example, Protocol 17: Falls, Protocol 18: Headache, and Protocol 26: Sick Person—would give EMDs a tool for faster identification of possible stroke patients and, consequently, a rapid deployment of EMS assistance.
Sources
1National Stroke Association. Explaining Stroke. http://www.stroke.org/site/PageServer?pagename=explainingstroke. Accessed May 21, 2013.
2World Health Organization. The top 10 causes of death. http://who.int/mediacentre/factsheets/fs310/en/. Accessed May 24, 2013.
3National Stroke Association. Warning Signs of Stroke. http://www.stroke.org/site/PageServer?pagename=symp. Accessed May 21, 2013.
4Adair G. Speed essential in treating strokes. Oct. 29, 2012. http://www.bbc.co.uk/news/uk-northern-ireland-20122455. Accessed May 21, 2013.
5Brice, J., et. al. STAT 911: Stroke Assessment Tool for 9-1-1 Dispatchers
