Recognizing the Signs of Stroke in the Prehospital Environment

Every three to four minutes, someone in the United States dies from a stroke.

Emergency medical services (EMS) personnel are often the first on the scene of a stroke in the prehospital environment. Stroke recognition and treatment is of premier importance to preserve brain tissue and limit the amount of disability the individual will suffer in the long-term. All EMS providers, including EMTs, other ambulatory staff and fire department personnel are required to undergo extensive training to increase their knowledge regarding that stroke prehospital training may include acute stroke certification, particularly recognizing the two types of stroke and identifying potential stroke-related complaints.

Upon arrival at the scene of an emergency, EMS providers and other first responders look for certain warning signs and acute stroke symptoms. Sudden numbness or weakness of the face, arm or leg, especially on one side of the body, is the most common sign of stroke, occurring in 94 percent of patients. Sudden confusion and trouble speaking or understanding speech is another common indicator of stroke, which is seen in 88 percent of patients.

Sudden trouble walking, dizziness and loss of balance or coordination are other hallmark symptoms of stroke, and are seen in 85 percent of patients. Sudden trouble seeing in one or both eyes, characterized by either blurred vision or total loss of vision, as well as the sudden onset of a severe headache with no obvious explanation, also represent common indicators of stroke, occurring in 68 percent and 61 percent of patients, respectively.

If witnessing a patient with stroke symptoms, many prehospital medical professionals will conduct a rapid assessment using the Cincinnati Pre-Hospital Stroke Scale. The scale, which dictates a three-item examination that has proven effective in the identification of individuals experiencing an acute stroke, follows the acronym of “FAST”:

Facial droop – One side of patient’s face does not move as well as the other.
Arm drift – Patient’s arm does not move or drifts downward when held extended.
Speech – Patient slurs words, uses the wrong word or cannot speak at all.
Time to call 911 – The presence of one of the above signs is associated with a high risk of stroke (72 percent), while the presence of all three signs suggest the risk of stroke is even higher (85 percent).

In addition to visual and physical assessment of signs and symptoms of potential stroke, prehosptial healthcare professionals may also conduct a brief interview with the patient or a caregiver to glean information about other potential risk factors for stroke. These risk factors commonly include:

High blood pressure
History of cardiovascular disease
Atrial fibrillation
Smoking
Diabetes mellitus
Obesity
Family history of stroke
History of previous stroke or blockage of circulation to the brain
High cholesterol
Physical inactivity
Heavy alcohol usage
Age over 55 (doubles the risk)
Ethnic background (heightened incidence of stroke in Native American, Hispanic American and African American populations)

Often this background information—in conjunction with an initial assessment of the patient’s symptoms—can help prehospital healthcare providers identify cases of potential stroke and tailor care accordingly to mitigate chances of death and disability in patient populations.

For more information, visit the overview of stroke courses offered online.

The information included in this article is based on the 2020 guidelines for CPR, first aid and advanced cardiovascular care.