Stroke Smart

You’re eating breakfast when suddenly the cereal spoon won’t cooperate and you become aware of numbness and heaviness in your right arm. When you try to stand up, your right leg won’t cooperate. For 700,000 people each year, these are some of the common presenting symptoms of a stroke.

While EMTs certainly have the ability to help a patient suffering from a stroke, effective treatment actually starts much earlier. Patients can begin by reducing certain risk factors that can cause a stroke. They can also learn to quickly identify the physical symptoms of a stroke in order to receive fast, effective treatment. But first some background on strokes.

We can divide strokes into two types: ‘wet’ or ‘dry’. Hemorrhages in the subarachnoid space or from an intracerebral vessel are obviously the wet strokes. Dry strokes are caused by the formation of blood clots in brain arteries or from emboli that travel to the brain and lodge in an artery, shutting off the blood supply.

For most stroke victims, we are talking about a thrombotic stroke from a blood clot that has formed in a cerebral artery, thus reducing blood flow (ischemia) to brain cells. This causes the brain to malfunction and if untreated can result in damaged brain tissue and permanent disability or death. Thrombotic strokes can be treated emergently thanks to the clot-dissolving medication, tissue plasminogen activator (TPA). However, there is a 3-hour time limit from definite onset of stroke symptoms to administration of TPA, and that includes a trip through a computed tomography (CT) scanner. The earlier TPA can be administered, the better the result. To be successful, ALL participants in the process must be stroke smart.

Being smart about stroke prevention begins with the patient’s recognition of risk factors that can lead to a stroke. Stroke risk factors are divided into those you can change and those you cannot.

If prevention fails and a stroke does occur, then treatment begins with timely recognition of stroke symptoms by the patient. The most common presenting stroke symptoms are:

• Sudden numbness or dead feeling on one side of the body
• Sudden painless weakness on one side of the body
• Sudden painless loss of vision
• Sudden loss of ability to express oneself verbally or in writing
• Sudden loss of ability to understand what people are saying
• Sudden onset of severe headache without a known cause

Once symptoms are recognized, the patient must get access to a medical facility with a CT scanner and the ability to administer TPA if indicated. The CT scan of the brain is essential to rule out a wet stroke; you don’t want to give a clot-buster when a brain hemorrhage is present. More than half of these stroke patients will obtain access via EMS. The role of EMS in an acute stroke from any cause is outlined in the recently published position statement from the National Association of EMS Physicians. In summary:

• Expeditious EMS dispatch and response
• Stroke-smart EMS personnel skilled in the stroke screening process
• Timely communication with the receiving medical facility
• Stroke protocols founded on evidence-based treatment and local resources
• Strategies of care targeting the acute stroke patient to maximize local and regional resources

In addition to using a stroke screening tool to identify those patients who may benefit from early notification and timely transport to a medical facility with a CT scanner and TPA, EMS offers additional care that can improve stroke outcome. Simply transporting the patient with their head level may improve blood flow to the brain, but should be done only if there are no signs of increased intracranial pressure and if the patient can tolerate lying flat. At any point during your care of the patient, treating and preventing the ups and downs that occur during homeostasis is important in helping brain cells survive.

Here are the current recommendations:

• Hypoxia decreases oxygen availability to brain cells, and supplemental oxygen is indicated to obtain normal oxygen saturation. For the stroke patient with normal oxygen saturation on room air, supplemental oxygen may or may not be beneficial.
• Hypotension requires fluid resuscitation to obtain and maintain a perfusing blood pressure for optimal delivery of oxygen and nutrients to the brain cells. For the stroke patient with a normal blood pressure, TKO the fluids or use a saline lock. If the patient is hypertensive, contact medical oversight for direction. Treating the hypertension may actually reduce cerebral blood flow.
• Hypoglycemia deprives the brain cells of their primary energy source. Be sure to replenish without causing hyperglycemia, which is detrimental to the stroke patient.
• Hypothermia for stroke patients may prove to be beneficial in the future, but for now, maintain a normal temperature and avoid hyperthermia by removing excess clothing and controlling temperature shifts in the ambulance. However, prevent shivering, which can increase body temperature.

Even if your system lacks rapid access to TPA, the recommendations above will have a positive impact on stroke outcome. Although a lot of information bullets have been covered, if we are equipped with enough ammunition, then we can improve our aim at stroke survival and post-stroke quality of life.

References

1. Prehospital and Hospital Delays After Stroke Onset – United States, 2005-2006. Morbidity and Mortality Weekly Report May 18, 2007/56(19);474-478. Retrieved August 15, 2007 from http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5619a3.htm
2. Adams HP, del Zoppo G, Alberts MJ, et al. AHA/ASA Guideline: Guidelines for the Early Management of Adults with Ischemic Stroke. Stroke. 2007;38:1655-1711
3. NAEMSP Position Statement: The Role of EMS in the Management of Acute Stroke: Triage, Treatment and Stroke Systems. Prehospital Emergency Care, 11:3, 312.
4. Millin MG, Gullett T, Daya MR. EMS Management of Acute Stroke – Out-of-Hospital Treatment and Stroke System Development. Prehospital Emergency Care, 11:3, 318-325.
5. Crocco TJ, Grotta JC, Jauch EC, Kasner SE, Kothari RU, Larmon BR, Saver JL, Sayre MR, Davis SM. EMS Management of Acute Stroke – Prehospital Triage. Prehospital Emergency Care. 11:3, 313-317.