What do you do if you witness or experience a stroke?

This week, I want to talk about stroke signs and symptoms.  Again, it is a little different than what has previously been written on my blog but I feel it is SO important and SO necessary to make people aware about this—the CDC reports that strokes are the leading cause of death in the US and nearly 130,000 people in the US die every year because of a stroke (1 in 19 deaths).  Strokes are a medical emergency!  Not only is it the leading cause of death, but strokes can cause severe disabilities in people: weakness or paralysis, cognitive issues, speech impediments, difficulty walking, etc.

The American Stroke Association, a branch of the AHA, has come out with an acronym called FAST which helps people in remembering and recognizing symptoms of a stroke.

·         F- facial drooping: often times a victim experiences one-sided weakness which can be manifested through facial drooping.  If you suspect facial drooping, ask the victim to smile.  Their smile will be lopsided.

·         A- arm weakness: again, this is a result of one-sided weakness.  Ask the victim to raise both arms in front of them. If one is unable to raise or is held lower than the other, this is a sign of stroke.

·         S- speech difficulty: ask the victim to talk.  They may say nonsensical things, are unable to communicate clearly, or have slurred speech.

·         T- Time is brain! If any of these signs manifest, call 9-1-1 immediately.

Outside of the acronym FAST, other signs may be evident: numbness or weakness of the leg, confusion, sudden blurred vision or blindness in one or both eyes, trouble walking, dizziness, loss of balance and sudden severe headache, often called “the worst headache of my life.”

If you or your loved ones are ever confronted with any of these signs or symptoms, do not hesitate to contact emergency medical services.  Quick recognition and identification of a stroke can save someone’s life!

What should you do if you find someone unresponsive?

For this week’s blog, I figured I will take a different approach.  In past blogs I discussed hypothermia as a post-resuscitation treatment after a sudden cardiac arrest (SCA).  But what can the layperson do if they witness someone experiencing a cardiac arrest?  This week I will talk about the proper way to perform CPR (cardiopulmonary resuscitation) so that the victim of a SCA has an increased chance of survival so that hypothermia may be used afterward.

The best resource for learning CPR is through the AmericanHeart Association (AHA).  New best practices and guidelines are always changing, so it is important to keep up to date.

When you see someone suddenly become unconscious or unresponsive, or find someone unconscious or unresponsive:

1.    Determine whether or not the environment is safe: Is there a fire around? Is the building about to collapse? There are 2 reasons for this: first, it will not do you or the victim any good if the environment is unsafe and you are risking yourself and second, if it is possible, pull the victim to safety.

2.    Once the environment is deemed safe, check the victim’s level of consciousness.  This can be assessed by shaking the victim and asking if they are okay.  If they are unresponsive, you can check the carotid artery for a pulse which is located in the neck.  You will also want to assess the victim for breathing.  If they are not breathing or are only gasping, then you will want to look into the victim’s mouth to see if there is something blocking their airway.

3.    If the victim is still unresponsive and a pulse is not palpable, immediately begin CPR.  Chest compressions are the first thing you will want to do.  You will want to interlock the fingers of your hands and begin chest compressions in the middle of the victim’s breastbone (sternum).  You will want to push hard and fast, usually about 100 beats per minute.  You will do 30 compressions before switching to 2 rescue breaths.

4.    After 30 compressions, 2 rescue breaths will be given to the victim.  In order to make these rescue breaths effective you will want to tilt the victim’s chin back to establish a patent airway.  When administering these breaths, you can check the victim’s chest for a rise—this indicates the breaths are effective.

5.    You will continue this cycle until 1 of 3 things occur: either first responders are available on the scene or if you are in a public place, someone brings an AED (automatic external defibrillator), or the patient is no longer unconscious or unresponsive.

6.    In the event that first responders are still not available and an AED is available, follow the prompts given by the AED.

The long list of CPR can be intimidating to those who have either never performed it or formally learned CPR.  The AHA always has classes available so if you are interested, I strongly recommend taking one.  As I mentioned before, guidelines are always changing and there are some new studies that have come out recently that say to not even worry about the 2 rescue breaths, just do the compressions because that will circulate what oxygenated blood is left. If you are ever confronted with this situation, do not panic! Just remember to check the environment, the victim, and then immediately begin chest compressions if nothing else. Remain calm, you can do it!

Methods of Cooling

In this week’s post I will discuss different methods of cooling for therapeutic hypothermia.  There are many different methods that can be used and hospitals employ them based on their set protocol—which is typically dependent upon the preference of the hospital or current evidence based research available that supports one method over another. There are two different types of cooling methods: surface and core cooling.  Surface cooling includes the use of blankets or ice packs whereas core cooling involves the use of chilled IV fluids administered directly into the veins of the patient. 

Surface cooling is beneficial in that it is the least invasive method of achieving hypothermia.  As mentioned before, ice packs and blankets can be utilized.  When compared to core cooling, this method of cooling is relatively inexpensive and can be initiated almost immediately after the hypoxic insult.  However, as with any procedure, there are some disadvantages.  While surface cooling reaches the appropriate temperature pretty quickly, it is very difficult to regulate the patient’s body temperature with this method. Another disadvantage is the direct application of the cold to the patient’s skin—this can cause tissue damage if it is done incorrectly or not monitored closely.

Core cooling involves the use of invasive IV fluids in order to achieve and maintain therapeutic cooling temperatures. Maintaining correct temperatures during cooling is critical.  If a patient’s temperature is not low enough, there is no benefit.  If a patient’s temperature is too low, there is an increased risk for adverse effects.  In contrast to surface cooling, core cooling allows the clinician to closely and accurately monitor the patient’s temperature.

When either of these methods are employed, paralytics and sedating drugs are used to keep the patient from shivering, which would negate the effects of TH.  If you are interested about the different cooling methods of TH, you can find more information here.

Who is a candidate for therapeutic hypothermia?

In my previous post, I gave a general overview of what therapeutic hypothermia (TH) is.  You'll remember, it is most often used for those who experience a sudden cardiac arrest (SCA) and who have subsequently been revived with CPR.  TH is clinically indicated for those who experience a SCA due to two abnormal heart rhythms: ventricular tachycardia (V-Tach) and ventricular fibrillation (V-Fib).  Other arrhythmias like asystole (no heartbeat at all) and pulseless electrical activity (there's electrical conduction going on in the heart but no actual beat) have not shown to benefit from therapeutic hypothermia.

So now we understand a little bit about the differences in the arrhythmias when TH is useful.  So what are the other qualifications a patient must meet in order to undergo TH? 

Patients who are considered for therapeutic hypothermia have to meet two kinds of criteria: inclusion criteria and exclusion criteria. As you might guess, inclusion criteria would include people as candidates.  If any person should fall under any part of the exclusion criteria, they are no longer considered as a candidate for treatment.

Inclusion criteria for TH are those who have V-Fib or V-Tach as their initial insulting rhythm, as mentioned earlier.  Typically these patients become unconscious very quickly so an estimated “down-time” is usually no more than 10-15 minutes from initial insult to the start of CPR.  Further, a patient included for TH should not be down for longer than 60 minutes from initial insult to what is called return of spontaneous circulation (ROSC). After ROSC, in order for TH to be of any use, the patient must be comatose.  Those who are conscious after ROSC obviously are in no need of therapeutic hypothermia because there are no neurological deficits.  Patients must also be intubated with mechanical ventilation and be at least 18 years old.

Exclusion criteria, or those who are not candidates are those who are pregnant, have known blood clotting disorders (hypothermia increases blood clotting times which puts hypothermic patients at risk for bleeding), and those who are comatose for any reason other than cardiac arrest (head injuries, strokes, etc).  Patients with a known do-not-resuscitate (DNR) status are not candidates for TH, as their wishes are, obviously, to not be resuscitated.

Therapeutic hypothermia is a wonderful treatment for those who are candidates to receive it.  Clinicians offering this treatment should be well aware of the inclusion and exclusion criteria before initiating it on any patient. If you would like more information, I will place more links below.

Post-Resuscitation Care

Therapeutic Hypothermia from MedScape

An Overview of Therapeutic Hypothermia

Clinically, therapeutic hypothermia (TH) has been used for over 70 years. However, it was first observed in ancient history where they realized hypothermia slowed the rate of bleeding.  TH has raised many controversies: is it beneficial? Do the risks outweigh any benefit? What is the safest way to administer TH? Throughout the years of research and controversy there are still many questions that remain.

 For those who are unfamiliar, TH is a medically-induced hypothermia.  The brain needs oxygen—it cannot survive without oxygen for more than 6 minutes.  When the brain is deprived of oxygen, a hypoxic brain injury ensues.  This can occur in instances of cardiac arrest when the heart is either not beating (either properly or not at all) or if a baby is having a difficult time passing through the birth canal and cannot transition from intrauterine to extrauterine life.  There are other instances of hypoxic brain injury but TH has proven most effective in these cases. Therapeutic hypothermia has shown to decrease the brain’s demand for oxygen by as much as 6% for every 1 degree Celsius the body temperature is lowered.  When TH is initiated after a hypoxic insult, there are fewer, sometimes no, long-lasting neurological effects.

 Patients who receive TH as a treatment are in a controlled environment, like an intensive care unit (ICU) although it can be initiated by a first responder or EMT.  TH is considered a high risk procedure due to the critical nature of the patients’ condition and also because of the side effects involved. Side effects include irregular heart rhythms, drops in blood pressure, increased risk of bleeding, fluid and electrolyte imbalances, and increased risk of pneumonia. If the patients’ wishes are unknown, it is up to the clinician’s expertise to determine whether or not the benefits outweigh the risks for that particular patient.

If you're curious about more information, you can find it here:
Neurologic Prognosis After Cardiac Arrest
Therapeutic Hypothermia: An old treatment gets a new look