EMS Stroke Care

Stroke Care should follow your local medical direction and treatment guidelines.  Here’s how we do it in North Central Connecticut.

EMS Role

When Emergency Medical Services (EMS) recognizes stroke in the field, and notifies the hospital either by radio patch or transmission, the hospital stroke team can be activated prior to the patient’s arrival. With enough notification, the patient can often go directly to CT Scan on the EMS stretcher. This single intervention has led to a marked decrease in door-to-needle time and improvement in patient outcome. The patient can receive an immediate evaluation by hospital neurologists and the decision can be made whether or not the patient meets the criteria for rTPA. The American Heart Association, recognizing the role EMS can play, has established a new goal of door-to-needle time of 60 minutes.  Even if the patient does not meet the narrow criteria for rTPA, the immediate neurological evaluation will lead to swifter interventions such as blood pressure control that will lead to better outcomes.

Stroke Assessment

Prehospital assessment of stroke should center on rapid identification of possible stroke symptoms such as numbness or weakness of face, arm and/or leg, acute vision changes, difficulty in speaking, trouble in understanding simple statements, confusion, trouble in walking or maintaining balance, and sudden severe headache.

The Cincinnati Stroke Scale

The Cincinnati Stroke Scale should be done on every patient suspected of stroke.

Just because a patient may score zero on the Cincinnati Stroke scale does not mean they are not having a stroke.  Posterior strokes, in particular, often present as zero Cincinnatis.

If a patient is zero on the Cincinnati scale, and they have a risk factor for stroke such as history of hypertension, smoking, diabetes, stress, atrial fibrillation, etc., ask these questions:

Did the patient’s symptoms happen suddenly and without an explanation such as trauma or intoxication?

Does the patient present with altered mental status?

Is the patient experiencing a sudden vision problem?

Does the patient have an altered equilibrium or vertigo?

A yes to the first question and a yes to any of the following three questions should heighten your suspicion of stroke as a possible cause of the patient’s condition.

Last Known Well Time

The rtPA clock starts with the onset of the stroke. The sooner rtPA is given the better the patient outcome. As time passes, the potential benefit of rtPA become less effective and the risk of rtPA becomes greater.  Determining when the patient was last seen at their norm is critical. Ask questions. Don’t be afraid to repeat the question to make certain the answers are correct.  Try to transport a witness if possible.

If a patient wakes up with left sided weakness at 6:00 A.M., but his wife states he got up and used the bathroom at 5:00 A.M., then the last known well time is 5:00 A.M.

Blood Glucose

Every suspected stroke patient should receive a blood glucose test. Hypoglycemia can often present with stroke like symptoms that are soon resolved with resolution of the hypoglycemia.

If blood glucose is below 70 mg/dl then administer as little D10 as necessary to restore normal levels.

Do the blood glucose test early in your assessment. A patient who you may suspect has hypoglycemia may be having a stroke, and any delay on scene can affect the patient’s eligibility for rtPA.

Blood Pressure Management

Obtain and record blood pressure. If hypertensive or normotensive, elevate head of stretcher to 30 degrees. If patient hypotensive, lay patient flat (if tolerated) and start IV Normal Saline titrated to blood pressure > 100 mmHg.

History

It is important to get a clear history not only of the event, but the patient’s baseline. Has the patient had previous strokes?  Do they have any residual effects?

 Medications

Is the patient on blood thinners? Do they take Coumadin? Do they take certain medications which will exclude them from being able to receive rtPA? If you can’t get an updated list, put all medication bottles in a bag and bring them to the hospital.

Early Notification

Early notification to the receiving hospital is essential to ensure the immediate availability of an appropriate in-hospital response.

Contact receiving hospital for ACUTE STROKE ALERT and include following information:

* Time of symptom onset/Last Known Well Time

* Description of neurologic deficits (include Cincinnati stroke scale)

* Blood glucose level

When contacting CMED say “I need a radio patch to (Name of Hospital) for a Stroke Alert.” This will help CMED prioritize your patch. Unlike STEMI, it is not necessary to ask for Medical Control.

Scene Time

Try to limit scene time to 15 minutes or less, and transport rapidly. Transport should be equivalent to trauma or acute myocardial infarction calls.  However, in your rush to get the patient to the hospital do not neglect to obtain pertinent information or assist a key witness in traveling to the hospital with you.

IVs

Limit IV attempts due to possibility of patient receiving rtPA. Use 18 or 20 gauge IV if possible.

Neuro Checks

Perform and document vital signs and neuro exam every 15 minutes (on both 911 calls and interfacility transfers involving stroke patients). Neuro exam should include Glasgow Coma Scale (GCS), arm and leg strength, and evaluation of pupils.

Stroke Recognition

The most importation contribution EMS can make to a patient’s recovery is recognition of a possible stroke and notification of the hospital.  Stroke can be very difficult to diagnose and many diseases and conditions such as brain tumors, seizures, migraine, hyponatremia, Bell’s Palsy, metabolic derangements and transient global amnesia can present as stroke mimics.  It is not as important that your correctly recognize each stroke as that you alert the hospital to the possibility that the patient may be having a stroke so they can have a neurologist or team of neurologists available to immediately examine your patient.

Hospital Destination

Unless the patient has a clear hospital preference, the patient should be brought to closest hospital capable of giving rtPA. Currently all destination hospitals in the North Central Connecticut Region report they are ready to treat stroke patients (who meet the proper criteria) with rtPA.  While many patients do not qualify for rTPA, for those that do, any delay limits the benefits and increases the considerable risks.

Direct to CT Scan

Possible stroke patients within the rTPA window (0-3 hours and 0-4.5 hours for some patients) should be brought directly to CT scan on the EMS stretcher if their condition allows and specific hospital policy permits.  The CT scan looks for signs of hemorrhage, or signs of ischemia, which can also rule out rTPA as patients with already visible ischemia are at higher risk for hemorrhagic conversion.  A patient with a clear CT Scan may be a candidate for rTPA.

rTPA

Those patients with clear scans may be eligible to rTPA, which will involve a risk/reward conversation between patient and/or family and the MD.  A meta-analysis of 9 randomized rtPA studies showed rtPA resulted in an absolute 10% improvement (at three months) when given within 3 hours and a 5% absolute improvement when given between 3 and 4.5 hours.  If the patient meets the criteria for rTPA and consent is obtained,  rTPA is given by a bolus, followed by a drip over an hour.

CTA

While the patient is receiving the rTPA drip, they may be taken back to CT scan for a CTA (angiogram) if the patient is suspected to be having a large vessel occlusion (LVO).  If the CTA scan reveals a large vessel occlusion and shows good collateral circulation beyond the occlusion, the patient may be a candidate for endovascular intervention.  If the stroke center does not have an endovascular interventionalist available, the patient may be transferred by EMS directly to an interventionalist suite at an endovascular center with the rTPA still running.  This is known as “Drip and Ship.”

Endovascular

Only a few stroke patients are eligible for endovascular intervention (clot retrieval), a promising intervention which can normally be done up to six hours after time of onset and typically requires the pre administration of rTPA.  A recent study in European Stroke Journal found only 1-14% of stroke patients would have met the criteria for recently published trials that demonstrated benefit to endovascular intervention.  Like rTPA, the success rate for endovascular therapy is far from universal.  In the MR. CLEAN study, 33% of stroke patients who received endovascular therapy in addition to rtPA were functionally independent after 3 months compared to only 19% who received rtPA alone.

Stroke Severity Scales

Several stroke severity scales have been developed in an attempt to help identify patients with large vessel occlusions who would benefit from endovascular intervention.  These scales include the Cincinnati Stroke Triage Assessment Tool (CSTAT), the Los Angeles Motor Scale (LAMS) and the Rapid Arterial Occlusion Evaluation Scale (RACE).  However, according to the American Heart Association “no randomized trial data exist to support a firm recommendation on the acceptable delay in arrival at a stroke center when considering re-routing a patient to a comprehensive stroke center.”   The possible benefits of early endovascular have to be weighed against the “potential harm of delayed initiation of IV alteplase.”  We await further research on this critical question.

Bottom Line

Have a high index of suspicion for stroke.

Notify the hospital with Stroke Alert.

Unless the patient has a clear hospital preference, transport possible stroke patients to the closest stroke hospital capable of rapidly delivering rtPA.

 

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