Pre-Hospital Care

Most strokes occur at home and the EMS is the first medical contact for more than half of all patients who have a stroke. Because EMS transport significantly shortens arrival time to the emergency department and because of the narrow window for delivery of time-dependent medications, EMS plays a pivotal role in the rapid treatment of stroke. A recent 3-year data analysis found that stroke patients brought in by EMS were twice as likely to receive a timely CT scan compared to those who did not use EMS (NSA, 2014a).

Nine-one-one dispatchers, first responders, EMTs, and paramedics are often the first source of medical information and play a vital role in the initial triage of potential stroke victims. It is imperative that the stroke system of care provide training and education for these people in order to minimize delays in pre-hospital dispatch, assessment, and transport (JAHA, 2010).

Studies have found that the greatest portion of the delay between onset of symptoms and emergency treatment is the time it takes for a patient to recognize the signs of stroke and decide to seek medical care. Between one-half and three-quarters of ischemic stroke patients do not arrive at the hospital within the 3-hour window of treatment that is needed to make an assessment and begin therapy. Some of the factors in the delays include lack of knowledge regarding stroke symptoms, treatment options, and the need for quick therapy (Williams et al., 2009).

Delays in treating stroke also occur because of poor recognition of stroke by 911 dispatchers and misdiagnosis of stroke by EMS personnel. Dispatch is a crucial link in the chain of care, yet dispatchers miss as many as 70% of stroke cases because they do not have the understanding or tools to properly assess the symptoms reported by callers. A similarly high misdiagnosis rate (61%) was documented for the responding EMS personnel when diagnosing stroke in the field (Williams et al., 2009).

These findings underscore the challenges facing the emergency systems of care. The lack of close coordination of stroke care among healthcare providers has resulted in a fragmented system for stroke prevention, emergency care, treatment, and rehabilitation (Williams et al., 2009).

To improve stroke outcome, a better integration of the facilities, agencies, and professionals that provide stroke care is needed. There needs to be rapid access to EMS, use of diagnostic algorithms, and EMS protocols that reflect the most current stroke treatment, as well as recommendations to dispatch EMS as rapidly as possible to improve outcomes. Emergency physicians and stroke experts should be involved in the design of protocols and training programs, stroke assessment and thrombolytic screening tools, and should encourage rapid transport to a stroke center (Williams et al., 2009).

The CDC, in collaboration with the North Carolina office of EMS, created the NEMSIS-based North Carolina Prehospital Medical Information System (PreMIS), to develop and implement EMS stroke performance improvement toolkits. The EMS toolkits focus on:

• Prompt recognition of stroke through the use of stroke screening
• Documentation of stroke symptom onset—the last time the person was seen well
• Screening the blood glucose of the patient for hypo- and hyperglycemia
• Maintaining EMS scene times of 10 minutes or less
• Rapid transport (with early notification) to a stroke center (Williams et al., 2009)

EMS providers should provide pre-arrival notification to a medical facility capable of providing acute stroke care. Pre-arrival notification has been found to increase the number of stroke patients who receive fibrinolytic therapy. Recent studies indicate a favorable benefit from triage of stroke patients directly to designated stroke centers (JAHA, 2010).

In 2006 the Minnesota Department of Health (MDH) and the Minnesota Stroke Partnership (MSA) conducted two surveys. The survey for emergency medical services organizations, mailed to every licensed ambulance service in Minnesota, asked about transportation policies and training needs. The survey for hospitals, mailed to every hospital in the state, asked about capacity to treat acute stroke (Tsai, 2008).

The Minnesota Stroke Partnership made several recommendations as a result of the survey:

• Prehospital EMS personnel should continue to treat stroke as an emergent event.
• First responders should be taught to recognize the signs of stroke and to communicate such information to ambulance personnel.
• Ambulance service organizations should be encouraged to use the Cincinnati Stroke Scale as the standard for assessing patients suspected of having stroke.
• Hospital emergency staff should be informed that the Cincinnati Stroke Scale standard is being encouraged, and prehospital providers should include instructions in their standard operating procedures to always verbally provide stroke scale information to hospital emergency staff.
• Prehospital EMS providers should be informed about the locations of primary stroke centers and educated about recent recommendations for stroke systems of care.
• Training should be provided for prehospital EMS providers on stroke issues annually or semi-annually. This training should be offered, but not mandated, for ambulance personnel.
• Classroom education or regional conferences and seminars should be provided.
• Internet-based training also should be provided as an option for continuing education. (Tsai, 2008)

Emergency Department Care

As in the prehospital phase, initial patient assessments made in the emergency department (ED) are based on evaluation of airway, breathing, and circulation, vital signs, and neurologic status. Most acute ischemic stroke patients arrive to the ED hemodynamically stable; however, patients with decreased level of consciousness may require airway management.

Acute stroke produces an increase in blood pressure in approximately 80% of patients and pressure must be monitored frequently. Control of blood pressure is important because significant elevation in blood pressure is an exclusion criterion for administration of thrombolytic therapy (recombinant tissue plasminogen activator, or rt-PA). Elevated blood pressure after administration of rt-PA is associated with increased risk of intracerebral hemorrhage.

When a suspected stroke patient arrives to the ED, triage is usually the function of the nursing staff. Acute stroke patients should be identified as quickly as possible to determine those eligible for thrombolytic therapy, which must be administered within 3 hours of known onset of stroke symptoms. The triage nurse, using the 5-level Emergency Severity Index, will assign most stroke patients an acuity level 2, meaning the patient needs immediate assessment. The nurse must be able to recognize symptoms suggestive of stroke and determine the last time the patient was seen normal (Jeffrey, 2009).

Because the benefit of thrombolytics in acute ischemic stroke is strongly time-dependent, ED personnel are trained to “think FAST”—meaning they look for (F) facial droop, (A) arm drift, (S) slurred speech, and (T) time to act quickly. Each minute that goes by, more nerve cells die. Treatment is most beneficial in the first minutes after stroke and declines steadily during the first 3 hours (Jeffrey, 2009).

Because there is no way to tell whether symptoms are from a TIA or an acute stroke, assume that all stroke-like symptoms signal an emergency—do not wait to see if they go away. A prompt evaluation (within 60 minutes) is necessary to identify the cause of the event and determine appropriate therapy. Depending on the patient’s medical history and the results of a medical examination, the physician may recommend drug therapy or surgery to treat or reduce the risk of stroke. Patients seen as ineligible for thrombolytic therapy immediately undergo a rapid secondary categorization to establish their treatment plan.

Response systems—including optimal time frames—must be established, maintained, and monitored in all emergency departments. Evaluation and treatment of acute stroke within one hour of arrival to the emergency department must include:

• An initial patient evaluation within 10 minutes of arrival in the ED. This should include patient history, insertion of 2 to 3 peripheral IVs, bedside blood glucose, initiation of lab work, and NIHSS (National Institutes of Health Stroke Scale) assessment by the physician. An electrocardiogram does not take priority over the CT scan, but should be done as soon as possible (JAHA, 2010).
• Notify the stroke team within 15 minutes of arrival.
• Initiate a CT scan within 25 minutes of arrival.
• Interpret the CT scan and labs within 45 minutes of arrival.
• Ensure a door-to-drug (needle) time of 60 minutes from arrival for eligible patients.

The patient should be transferred to an inpatient setting, preferably a stroke unit, within 3 hours of arrival to the emergency department (JAHA, 2010).

Because of the narrow therapeutic window for the use of thrombolytic medications, acute stroke teams are recommended to ensure the fastest onset-to-treatment time possible. The teams should comprise:

• Code team—responds to a code pager and delivers urgent treatment. May consist of a neurologist, ED physician, and nurse.
• Task force—works daily to facilitate patient access to treatment. May include members from neurology, emergency medicine, neurosurgery, nursing, pharmacy, laboratory, physical medicine, and rehabilitation (Ellmers, 2013)

The NIH Stroke Scale

The American Heart Association recommends that all emergency departments assess the severity of stroke using the National Institutes of Health Stroke Scale (NIHSS). The NIHSS is a graded neurologic examination assessing consciousness, eye movements, visual fields, motor and sensory impairments, ataxia, speech, cognition, and inattention. The scale was developed as a communication tool; it is simple and quick, and has shown significant reliability across diverse groups, settings, and languages. However the NIHSS also contains items with poor reliability and redundancy. The modified NIHSS (mNIHSS) minimizes redundancy and eliminates items with poor reliability (Meyer & Lyden, 2010).

Note: Since the mNIHSS is more reliable, it allows for improved communication, better medical care, and refinement of trial enrollments. The mNIHSS should serve as the primary stroke clinical deficit scale for clinical and research aims (Meyer & Lyden, 2010).

The NIHSS is used to evaluate the level of impairment sustained by a stroke patient, immediately and at intervals post onset. Scores increase as neurologic deficits increase. Although a level of neurologic deficit on the NIHSS has not been established for treatment with thrombolytics, the Food and Drug Administration (FDA) has included a package insert in rt-PA instructions listing a score greater than 22 as a warning. Additionally, patients with a score higher than 22 are at greater risk for hemorrhage transformation if they are given rt-PA. The mNIHSS is summarized in the table below.

For hemorrhagic strokes, the Glasgow Coma Scale is used in addition to the NIH Stroke Scale to determine level of consciousness and severity of the underlying change of consciousness. The Glasgow Coma Scale ranges from 3 to 15, in which progressively higher scores indicate higher levels of consciousness.

Imaging Studies

[This section taken largely from NINDS, 2015a, except where noted.]

The most important function of an imaging study for acute stroke is to differentiate between ischemic and hemorrhagic stroke. It can also be used to rule out other conditions such as tumors. Further, imaging studies can be used to determine the extent of the ischemic damage and to guide the use of therapies.

There are a variety of imaging devices used to evaluate stroke patients. The most widely used imaging procedure is the computed tomography (CT) scan. Also known as a CAT (computed axial tomography) scan, CT creates a series of cross sectional images of the head and brain. Because it is readily available at most major hospitals and produces images quickly, CT is the most commonly used diagnostic technique for acute stroke.

CT also has unique diagnostic benefits. It will quickly rule out a hemorrhage, can occasionally show a tumor that might mimic a stroke, and may even show evidence of early infarction. Infarctions generally show up on a CT scan about 6 to 8 hours after the start of stroke symptoms.

If a stroke is caused by hemorrhage, a CT can show evidence of bleeding into the brain almost immediately after stroke symptoms appear. Hemorrhage is the primary reason for avoiding thrombolytic therapy. Thrombolytic therapy cannot be used until the doctor can confidently diagnose the patient as suffering from an ischemic stroke because this treatment could make a hemorrhagic stroke worse.

Magnetic resonance imaging (MRI) is also used with stroke patients. MRI uses magnetic fields to detect subtle changes in brain-tissue water content. One effect of stroke is the slowing of water movement, called diffusion, through the damaged brain tissue. MRI can show this type of damage within the first hour after stroke symptoms start. The benefit of MRI over a CT scan is more accuracy and earlier diagnosis of infarction, especially for smaller strokes, while showing equivalent accuracy in determining when hemorrhage is present. MRI is more sensitive than CT for other types of brain disease, such as brain tumor, that might mimic a stroke. MRI cannot be performed in patients with certain types of metallic or electronic implants, such as pacemakers.

In 2010 the American Academy of Neurology concluded that diffusion-weighted imaging MRI is superior to non-contrast CT scans for diagnosing ischemic stroke within 12 hours of onset of symptoms. However, due to time constraints for administration of thrombolytics, the longer time required to complete an MRI, and because MRI is often not immediately available, a non-contrast CT is still recommended to rule out hemorrhagic stroke in patients being considered for thrombolysis (Anderson, 2010).

Other types of MRI scans—often used for the diagnosis of cerebrovascular disease and to predict the risk of stroke—are magnetic resonance angiography and functional magnetic resonance imaging (fMRI). Neurosurgeons use magnetic resonance angiography to detect stenosis (blockage) of the brain arteries inside the skull by mapping flowing blood. Functional MRI uses a magnet to pick up signals from oxygenated blood and can show brain activity through increases in local blood flow.

Duplex Doppler ultrasound and arteriography are two diagnostic imaging techniques used to decide if an individual would benefit from carotid endarterectomy—used to remove fatty deposits from the carotid arteries to help prevent stroke. Doppler ultrasound is a painless, noninvasive test in which sound waves above the range of human hearing are sent into the neck. Echoes bounce off the moving blood and the tissue in the artery and can be formed into an image. Ultrasound is fast, painless, risk-free, and relatively inexpensive compared to magnetic resonance angiography and arteriography, but it is not considered to be as accurate as arteriography.

Arteriography involves use of an x-ray of the carotid artery that is taken as dye is injected into the artery. The procedure carries its own small risk of causing a stroke and is costly to perform. The benefits of arteriography over magnetic resonancing techniques and ultrasound are that it is extremely reliable and still the best way to measure stenosis of the carotid arteries.

In-Patient Hospital Care

In some cases stroke patients are transferred to intensive care until they are stabilized. Those who have received rt-PA are always sent to intensive care, as are many of those with hemorrhagic stroke.

Delivery systems for acute stroke hospital care are relatively primitive compared to systems for state-of-the-art emergency cardiac care. This is partly a reflection of being able to provide only supportive care to ischemic stroke patients until the approval of rt-PA. The approval of intravenous rt-PA for selected patients with ischemic stroke exposed these deficiencies and mandated changes in the hospital care system. These long-needed changes will also benefit patients with hemorrhagic strokes (NINDS, 2014a).

Once a patient has been evaluated and treated in the ED, the patient should be transferred to a specialized stroke unit (usually intensive care). Primary and comprehensive stroke centers have stroke units with specially trained staff and a multi-disciplinary approach to treatment and care of stroke patients. These units have been shown to be superior to general medical units and have been shown to result in positive effects that last for years. Stroke unit care reduces the likelihood of death and disability by as much as 30% in men and women of any age with mild, moderate, or severe stroke (AHRQ, 2010a).

Nursing care focuses on continued stabilization of the stroke patient. Vital signs and neuro checks must be done every 15 minutes for 2 hours after administration of rt-PA, then every 30 minutes for 6 hours, and every hour for the next 16 hours. The NIH stroke scale is done every hour for the first 24 hours after rt-PA administration. The NINDS rt-PA Stroke Study and the AHA recommendations for rt-PA include strict monitoring and regulation of blood pressure below defined upper limits with antihypertensive agents. There are protocols for emergency management of hemorrhage in rt-PA-treated patients, specific guidelines for the control of hypertension, and recommendations for management of bleeding complications. Any neurologic changes must be reported to the physician immediately (NINDS, 2015a).

In addition to careful monitoring and treatment of blood pressure and neurologic status, it is important to prevent hypoxia, maintain euthermia (normal body temperature), and control blood glucose. Other complications from stroke (eg, deep vein thrombosis, prevention of urinary tract infection) must be addressed. All patients who have had a stroke must have a swallow evaluation prior to being given anything by mouth to prevent aspiration pneumonia. During this time the focus will be to discover the cause of the initial stroke, prevent complications from treatment, and initiate therapies to prevent another stroke (JAHA, 2010).

Specialized Stroke Centers

[This section is from The Brain Attack Coalition (Adams et al., 2007).]

The concept of specialized stroke centers evolved in response to the complexity of caring for patients with acute stroke. The Brain Attack Coalition recommended establishing two tiers for stroke centers: primary stroke centers (PSCs) and comprehensive stroke centers (CSCs). The Joint Commission now provides accreditation for both. These centers have the following characteristics:

• Primary Stroke Center (PSC): Designed to maximize the timely provision of stroke-specific therapy, including the administration of rt-PA; the PSC is also capable of providing care to patients with uncomplicated stroke.
• Comprehensive Stroke Centers (CSC): Shares the commitment that the PSC has to acute delivery of rt-PA and also provides care to patient with hemorrhagic stroke and intracranial hemorrhage, as well as to all patients with stroke who require emergent advanced imaging, intra-arterial therapies, neurosurgical interventions, and management in a neurosurgical intensive care unit.

PSCs and CSCs are most effective when integrated into a regional stroke system of care so that patients are treated at the most appropriate level based on factors including severity, co-morbidities, and timing. Integrating pre-hospital services (911 and EMS) into this system of care, ensures that the patients receive the most appropriate care from field to bed. Additionally, stroke centers have personnel trained in the monitoring of stroke vital signs, including the following:

• Blood pressure
• Glucose levels
• Temperature
• Oxygenation
• Change in neurologic status

A further tier, acute stroke-ready hospitals, is being defined as hospitals having most of the resources needed to emergently evaluate and potentially treat with fibrinolytics, possibly with the assistance of remote stroke care experts done through telemedicine. These systems of care must manage patient transactions following regional guidelines in order to optimize outcomes in patients requiring care at remote sites.

Overall Coordination of Care

Once the patient is identified as a potential stroke patient, ED evaluations are fast-tracked to allow completion of laboratory tests and non-contrast head CT scans, as well as to notify stroke staff. Some EDs have developed code stroke protocols for their department. These protocols extend to EMS personnel, who are trained to recognize possible stroke symptoms and arrange for preferential transport to a PSC or CSC if one is available.

Code stroke teams are a system-based approach requiring cooperation of the ED, radiology, pharmacy, neurology, and ICU staff. A successful stroke system of care ensures effective communication and collaboration among the agencies, services, and individuals providing prevention, timely identification, triage, transport, treatment, and rehabilitation of stroke patients.

Once the patient is stabilized, the stroke team includes consultations with additional team members who can provide more comprehensive services once the critical phase is over. These consultations may include:

• Occupational therapists
• Physical therapists
• Speech therapists
• Rehabilitation therapists
• Dietitians
• Home health care coordinators
• Social Workers
• Psychiatrists