Stroke: Time is brain in delivering EMS care

The sooner treatment is started, the smaller the area of permanent damage will be


Stroke is the third leading cause of death in the United States and one of the leading causes of long-term disability. Stroke refers to the acute neurological impairment that follows an interruption in blood supply to a specific region of the brain1.

It is beneficial to classify strokes as either hemorrhagic or ischemic. Ischemic strokes account for 87 percent of all strokes, and treatment that can dramatically improve outcome is available for a certain subset of carefully screened patients.

Time is brain. For every minute stroke is left untreated, an estimated 1.9 million neurons are destroyed2. Each hour in which treatment fails to occur, the brain loses as many neurons as it does in almost 3.6 years of normal aging.

Research data indicate that 29 percent to 65 percent of patients with signs or symptoms of acute stroke access their initial medical care via local EMS.

Also, EMS is strongly associated with decreased time to initial physician examination, initial computed tomography (CT) imaging, and initial neurological evaluation3.

All of these are important when determining which treatment modality would provide the greatest benefit for the patient. The sooner treatment is started, the smaller the area of permanent damage will be and the better the quality of life the patient will have.

Critical EMS assessments and actions1

  • Support ABC's
  • Perform prehospital stroke scale
  • Establish time when patient was last known normal
  • Transport: consider triage to a center with a stroke unit (consider bringing witness)
  • Alert hospital
  • Check glucose

EMS
A rapid prehospital stroke assessment should be preformed; either the Cincinnati Stroke Scale or the Los Angeles Prehospital Stroke Screen. Facial paresis, arm drift, and abnormal speech are highly predictive of an acute stroke.

If stroke is suspected, the patient is time critical until the type of stroke can be determined. This means the patient should be taken to a facility that has the resources necessary to rapidly assess, diagnose, and be able to provide the definitive treatment required within the appropriate time frame1

Helicopter transport to a regional stroke center can be very beneficial, but early notification is important to eliminate delays. This link can be used for a list of verified centers.

Patients often ignore or deny symptoms. EMS responders can make a significant positive impact in treatment by giving credit to even the more minor type of symptoms, and determining as close as possible the time of onset.

When was the patient last seen normal? Time of symptom onset is the single most important element of the patient's history.

Obtaining a cell phone number from a caregiver or close family member may provide answers or necessary consent later, after the patient arrives at the hospital.

If protocols allow, transporting the responsible caregiver with the patient to the hospital may also save valuable time with detailed history or signing consents for definitive treatment. 

Symptoms of a stroke may be:

  • Sudden weakness or numbness of the face, arm, or leg
  • Sudden confusion
  • Trouble speaking or understanding
  • Sudden trouble with vision, one eye or both
  • Sudden trouble walking
  • Dizziness or loss of coordination
  • Sudden severe headache

When taking a history, particular attention should be paid to identifying anticoagulant, antiplatelet, and antihypertensive drugs. 

The 7 D's of ACLS Stroke Care are:

Detection: Early recognition
Dispatch: EMS activation
Delivery: Transportation with appropriate prehospital care
Door: Immediate general neuro assessment with predefined targets
Data: CT Scan, Serial neuro exams, Review for rtPA criteria, Review patient data
Decision: Patient candidate for tPA? 
   ~Review risks vs benefits with patient and family
   ~Obtain informed consent
Drug: Begin rtPA treatment within 3 hour time limit
*rtPA - (Recombinant Tissue Plasminogen Activator)

ED treatment  
Management of patients with stroke symptoms requires a team approach. This is a time dependant patient and having a protocol in place with clear directions spelled out will provide a rapid organized flow of care.

Alert the Stroke Team, or plans should be made for a rapid transfer to a regional stroke center.

Oxygen, cardiac monitor, pulse oximetry, IV, blood draw for labs, bedside glucose, general and neurologic assessments and non-contrast head CT should all be quickly accomplished. 

For the neurologic assessment, an NIHSS (National Institutes of Health Stroke Scale) score should be calculated as soon as practical, but should not slow the progressive movement to CT. This can be helpful in determination of candidates for reperfusion therapy with rtPA.

Current accepted guidelines for reperfusion therapy with rtPA are based on studies from 2007. The 3 hour maximum time limit for therapy is based on these and, of course, the sooner treatment can be initiated, the smaller the area of permanent damage.

In spite of our best efforts, many patients fall outside this window of time. There are other treatment options available that can be provided outside of the 3 hour window. These are available primarily at regional stroke centers.

Take-home points:

  • Most strokes are ischemic and treatment is available, but must be started within a 3 hour time from onset of symptoms
  • EMS utilization for transport to the hospital has been shown to greatly reduce time to diagnosis
  • Having a family member immediately available at ED arrival for information and / or consent may play an important role for treatment initiation in the 3 hour time limit
  • Early hospital and stroke team notification can minimize delays

References:

1. American Heart Association. (2010) ACLS Resource Text for Instructors and Experienced Providers. pp 155-177.

2. Saver J. Time is brain-quantified. Stroke 2006; 36: 263-6.

3. Schwamm et al. Translating Evidence Into Practice: A Decade of Efforts by the American Heart Association/American Stroke Association to Reduce Death and Disability Due to Stroke. A Presidential Advisory From the American Heart Association/American Stroke Association. Stroke (2010) pp. STR.0b013e3181d2da7dv1

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