Emergency Medical Services Management of Acute Stroke Patients

Jennie Helmer, ACP, M.Ed.

Introduction
According to the American Stroke Association, stroke is the third-leading cause of death in the
United States. It is also a major cause of permanent disability and results in billions of dollars in
medical costs and lost productivity. Approximately two-thirds of all patients who seek acute care
for stroke arrive at the emergency department by ambulance. Transport by paramedics is safer for
these patients and ultimately enables patients to be triaged to appropriate hospitals that provide
immediate and targeted stroke services. Ultimately, treatment for stroke involves thrombolytic
therapy. This can only be done properly in the hospital, and there is a narrow window for treatment.
Due to stroke being a time-sensitive condition, brain cells are dying and effective treatment must
start as early as possible, Emergency Medical Service (EMS) personnel are required to take quick and
rapid action.

Stroke Presentation & Types
A stroke is defined as an acute impairment of neurological function that results from an interruption
of cerebral blood flow to a specific area of the brain. There are two main types of stroke: Ischemic
stroke and Hemorrhagic stroke. Ischemic stroke results from the occlusion of a cerebral artery by
a blockage or a clot. Hemorrhagic strokes occur from a cerebral vessel that ruptures, disrupts the
blood flow and allows bleeding in and around the brain.

Ischemic Strokes
Approximately 80-85% of all strokes are ischemic. The primary etiology of these strokes is from a
blockage of a cerebral artery that obstructs blood flow to an area of the brain. The most common
cause of ischemic stroke is atherosclerosis with rupture of the plaque, or plaque buildup, leading to a
blockage.

Hemorrhagic Stroke
A hemorrhagic stroke is due to a rupture of a cerebral vessel, with bleeding occurring into brain
tissue or area surrounding the brain. Approximately 17% of all strokes are hemorrhagic in nature.
When a vessel ruptures, the blood leaks from the vessel, accumulates in the brain and causes
brain tissue to become compressed. The two major types of hemorrhagic stroke, intracerebral
and subarachnoid hemorrhage, produce abrupt onset of severe and dramatic signs and symptoms
(sudden onset of the “worst headache” ever experienced, nausea, vomiting, light intolerance, and an altered mental state). Hemorrhagic stroke carries a higher acute mortality rate than ischemic
stroke.

Transient Ischemic Attack (TIA)
A transient ischemic attack (TIA) is a condition where the patient suffers a temporary interruption
of blood flow to an area of the brain. Since the interruption of blood flow is only temporary, there
is no permanent neurological dysfunction or damage associated with the blocked blood flow.
TIAs produce sudden onset of the same signs and symptoms of a stroke; however, the signs and
symptoms typically only last for a few minutes, to usually no more than one hour. TIAs are predictive
of impending stroke in patients and the risk of stroke within 90 days of a TIA may be as high as
17%, with the greatest risk during the first week (1). For EMS personnel, getting the job done right
involves educating the TIA patient about the high risk of suffering a true stroke in the near future,
and to seek appropriate supportive, medical care.

Stroke Pathology
Stroke is a medical condition in which poor blood flow to the brain causes cell death and improper
brain function. Lack of blood may result in significant motor (movement), sensory or cognitive
(thought or perception) dysfunction, or even death. There are two critical elements that brain cells
require for normal function: oxygen and glucose. Without these two elements, brain cells begin to
malfunction and will eventually die.

Following the occlusion of a cerebral artery, focal brain ischemia develops with reduced cerebral
blood flow, which are most severe in the core of the lesion and more moderate in the surroundings
area (penumbra). There is strong evidence for the general association between time from onset
and irreversible tissue damage. The so-called penumbra hypothesis states that “the core of the
focal ischemic lesion is irreversibly destined to die while the surrounding areas has lost its function
due to reduced blood supply but has maintained metabolic and structural integrity, and hence, may
be salvaged” (2). If the blood flow is restored to these ischemic areas, brain cells will continue to
function and become active. This may be evident in the patient who initially presents as a severe
stroke with significant neurological dysfunction, who then later regains function of many of the
previously dysfunctional areas.

Signs and Symptoms of Stroke
Often, the signs and symptoms of a stroke are subtle and may go unrecognized for a period of
time by the patient and family. However, like a heart attack, immediate recognition of the stroke
condition and initiation of treatment can reduce the amount of disability and death. This may
mean the difference between a patient who suffers significant permanent disability and one who
recovers completely, or with only minor deficits. For EMS, it is imperative in your history taking
that you attempt to precisely determine the onset of the first sign or symptom of stroke, no matter
how subtle. This will be vital information to the receiving medical facility in determining treatment
options.

The signs and symptoms of a stroke may include any of the following:

The signs and symptoms of a stroke may include any of the following:

Stroke Treatment
As with most critical patient presentations in EMS, it is critical to ensure an adequate airway, and
appropriate ventilation, oxygenation and circulation status in your initial assessment. Stroke patients
are at an increased risk of loss of airway control and aspiration. Protect your patient from aspiration
through positioning, or if vomiting is severe, attempt suctioning or intubation as your guidelines
indicate. Support ventilations as required, ensure suitable oxygenation and follow your respective
guidelines. Blood glucose levels should be confirmed and hypoglycemic patients treated and
re-assessed. Stroke patients require rapid transport with advance notification to the most
appropriate medical facility.

Several pre-hospital stroke identification tools have been developed and validated. They enable
dispatch to prioritize stroke care and EMS crews to pre-notify hospital-based stroke teams. Three
commonly used tools in EMS include the Cincinnati Prehospital Stroke Scale, the Los Angeles
Prehospital Stroke Screen, and the FAST VAN tool (which identifies large vessel occlusion and the
need for thrombectomy). Using these tools to support common-language communication of stroke
identification, EMS personnel should provide advanced notification to the receiving hospital of an
inbound stroke patient. This notification permits early activation of the stroke team and readiness
of in-hospital brain imaging facilities, and accelerates the initiation of definitive treatment at hospital
arrival.

Stroke Timelines
Pre-hospital phase:
This timeline starts with symptom onset and ends with hospital arrival. This timeline includes on
scene EMS management and transport time. Patients with ischemic stroke who arrive at a hospital
within a 4.5-hour time window from witnessed symptom onset (or when last seen well) may be
eligible to receive thrombolysis. Thrombolysis involves the administration of alteplase or tissue
plasminogen activator (tPA), which is a “clot-busting” drug. Early administration of tPA improves the
chance of recovering from a stroke. Studies show that patients with ischemic stokes who receive tPA
are more likely to recover fully or have less disability than patients who do not receive the drug (3).
As well, patients treated with tPA are also less likely to require long-term care in a nursing home.

Thrombolysis may be provided alone or in combination with endovascular thrombectomy which has
a 6-hour time window for most patients. Highly selective patients may be eligible for endovascular
thrombectomy up to 24-hours from symptom onset. There is definitive evidence of thrombectomy
for acute stroke with large vessel occlusion, as identified in the field through the paramedic use of
the FAST VAN tool.

The treatment of hemorrhagic stroke may require medication, surgery, or procedures to stop the
bleeding and save brain tissues.

Conclusion: Advances in Stroke Care
The goal of stroke care is to minimize brain injury and to maximize the patient’s recovery. The sooner
the treatment, the better the chance for recovery. Recent innovations have opened new perspectives
for stroke diagnosis and treatment before the patient arrives at the hospital. These include stroke
recognition by dispatchers and paramedics, mobile telemedicine for remote clinical examination
and imaging, and integration of modern diagnostics such as brain CT scanners, duplex sonography
and point-of-care laboratories in ambulances; and the integration of remote clinical examination and
imaging review via mobile telemedicine. (2). As well, several clinical trials are now being performed
in the prehospital setting testing delivery of neuroprotective, antihypertensive, and thrombolytic
therapy in the field.