Chapter 12: Circulatory Emergencies

Overview

Circulatory emergencies are those that affect the heart or vascular system. While a circulatory emergency can often appear as a sudden, dramatic emergency, the underlying cause may be a condition that has been developing over a period of years or even decades. Because circulatory emergencies can deprive vital organs of oxygen, they are often immediately life-threatening.

Circulatory Emergencies

Angina. This is not a heart attack. It develops when the heart needs more oxygen than it gets during physical exertion. Pain usually lasts less than 10 minutes, and the person will describe it as a constricting chest pain that spreads to the neck, jaw, and arms. They will usually have prescription medication if this has happened before (typically sublingual nitroglycerin in a spray or pill form). Nitroglycerin is a vasodilator, which means that it causes blood vessels to dilate (expand). This allows blood to pass more easily through narrowed vessels, increasing the flow of oxygenated blood to the myocardium and reducing the workload of the heart.

  • Stable angina usually occurs while a patient is exercising or under emotional stress and follows a predictable pattern. Usually, the pain can be relieved with a combination of rest and medication: A patient experiencing stable angina should cease any physical activity that could increase the body’s oxygen demands and rest in a position of comfort. Recognizing the difference between stable angina (which is usually not life threatening) and the symptoms of a myocardial infarction (MI) is crucial. The patient should track how long his or her angina typically lasts and which factors are effective in reducing it so that this baseline can be used to evaluate any future cases.
  • Unstable angina is angina that is not typical for the patient. It may occur when the patient is at rest, last longer than 10 minutes, or not respond to medication. Unstable angina may also be more painful or last longer each time it occurs, or may happen with increasing frequency. Unstable angina occurs when the myocardium (heart muscle) is receiving insufficient oxygenated blood. It is similar to an MI, except that the effects are usually temporary and do not result in permanent damage. Unstable angina is a warning sign that an MI may be imminent. Because the signs and symptoms of unstable angina and of an MI are difficult to distinguish in the field, you should provide essentially the same care for the two conditions.

If you are unsure whether the patient is experiencing angina or an MI, treat the patient for an MI.

Myocardial Infarction (Heart Attack). When a great deal of heart tissue is deprived of oxygen and dies, it is called a heart attack. The most prominent system of a heart attack is persistent chest pain or discomfort. Brief, stabbing chest pain or pain that feels more intense when the person breathes deeply is usually not caused to a heart attack. The pain is constant and is usually not relieved by resting. Quick treatment is to crush and swallow aspirin to dissolve possible clots. Sometimes a person (typically women or people with diabetes) may only present soft symptoms, such as difficulty breathing, muscle soreness, or stress.

Treating Angina and a Heart Attack. Recognize the symptoms. First, have the patient stop and sit comfortably. Have the patient crush and swallow aspirin as well as their angina medication. Find a defib and pre-place it on the patient’s body. Immediate evac.

Congestive Heart Failure (CHF). CHF is the condition in which the heart loses its pumping ability. This may be the result of a heart attack or from several heart-conditions. The result is that fluids and blood back up into the lungs or body tissue.

  • Left-sided HF: Fluid backs up into the lungs causing pulmonary edema. Symptoms: Increased HR and RR, history of severe shortness of breath when lying down, cyanosis, coughing up foamy sputum, wheezing, panic, pale clammy skin, and confusion.
  • Right-sided HF: Caused by left-sided HF when eventually the right side is unable to keep up with the increased workload. Right-sided HF may also occur as a result of a pulmonary embolism, long-standing COPD, or MI. When the right side fails, blood back up into the body’s veins causing a pooling of fluid in the tissues of the extremities. This is most noticeable in the feet when the person is sitting or standing, or in the lower back if the person is bedridden. Right-sided heart failure is seldom life-threatening, however together they cause cardiac arrest. Symptoms include swelling of the feet and ankles, urinating more frequently at night, heart palpitations, irregular fast heartbeat, weakness, and fainting.
  • Jugular Venous Distention (JVD). Jugular venous distension (JVD) refers to a visible swelling of the jugular vein in the neck. It is an indication of increased blood volume in the patient’s circulatory system, or anything that interferes with the flow of blood into the right atrium or the right ventricle. Essentially, JVD increases whenever the venous return of blood to the heart overwhelms the heart’s ability to pump it back out to the body. It is primarily seen in patients with right-sided heart failure. JVD is most easily assessed when a patient is in the Semi-Fowler’s position (inclined 30 to 45 degrees). It should be visible in a supine patient as well.

Treating CHF. One hundred percent oxygen should be given immediately. If nitroglycerin is available, give 1 tablet every 5 minutes under the tongue for a maximum of 3 tablets. Hold the nitroglycerin if the person experiencing congestive heart failure becomes light-headed or if the person’s pulse weakens. If the person takes a water pill, give double the normal daily dose. In very severe cases in which emergency medical personnel are far away, rotating tourniquets in one extremity at a time for no more than 10 minutes can decrease the workload on the heart. Only people trained in prehospital care should attempt this treatment, and then only with extreme caution.

Stroke. A stroke is a serious disruption of blood flow to a part of the brain. The affected brain tissue quickly becomes hypoxic and suffers damage. The effects of a stroke vary based on which part of the brain is affected: The patient will experience deficits in the areas that are controlled by the damaged tissue (speech, motor skills, memory, etc.). Effects can range from minor to catastrophic, depending on the location and extent of the damage.

There are two main causes of strokes: Either an artery in the brain is blocked (ischemic stroke), or an artery in the brain ruptures (hemorrhagic stroke), spilling blood into the surrounding tissues. More than 4 out of 5 strokes are ischemic strokes, which result over time due to cardiovascular disease. Hemorrhagic strokes result from head injuries, hypertension, or a ruptured aneurysm (a weakened section of an artery wall).

Signs include: Remember FAST: Face numbness, arm weakness, slurred speech, time is critical. The signs and symptoms of a stroke or TIA vary based on which brain tissues are affected: The person will have deficits in the areas controlled by that tissue. If the language centre is affected, for example, the person may have difficulty communicating. A person may experience weakness (hemiparesis) or paralysis (hemiplegia) on one side of the body. More than one area of the brain can be affected.

Cincinnati Prehospital Stroke Scale (CPSS). The CPSS is a set of simple tests that can be used to assess face droop, arm weakness, and speech abnormalities in a patient suspected of having a stroke. If the patient has abnormal results in any of these areas, you should suspect a stroke.

  • Face Droop: Have the patient smile.
    • Normal: Both sides of the face move equally.
    • Abnormal: One side of the face does not move as well as the other side
  • Arm Weakness: Have the patient close both eyes and hold their arms out straight for 10 seconds.
    • Normal: Both arms move equally or neither arm moves at all.
    • Abnormal: One arm does not move or arms drift unequally.
  • Speech Abnormalities: Have the patient repeat a well-known saying (e.g., “The early bird gets the worm.”)
    • Normal: The patient uses the correct words and does not slur.
    • Abnormal: The patient uses the incorrect words, slurs the words, or does not speak at all.

Care: Rest them in a comfortable position and do not give them aspirin or anything to eat or drink. A patient may have difficulty managing their airway, and will likely be very confused. Keep the patient calm, and if the patient must be rolled into the recovery position and is experiencing weakness or paralysis on one side, position the patient with the affected side of the body downwards. The patient must be evacuated as soon as possible. When notifying the hospital of the patient’s condition, it is important to include the time of symptom onset so that treatment can be planned accordingly.

Transient Ischemic Attack (TIA) .A TIA is similar to a stroke in its signs and symptoms, but usually resolves quickly without permanent tissue damage. It is caused by a temporary restriction in blood flow to part of the brain and resolves when the blockage clears. Even if stroke signs and symptoms disappear, the patient is not out of danger. A TIA is sometimes referred to as a warning stroke, as someone who has experienced a TIA is at a significantly increased risk of having a stroke. Aside from the duration of signs and symptoms, a TIA is essentially identical to a stroke. TIA patients require immediate medical care as well: Don’t delay transport to see whether a patient’s condition changes.

Cardiac Arrest. Someone in cardiac arrest is not breathing and does not have a pulse. They need CPR, defibrillation as soon as possible, and advanced care. The CPR should be given as soon as possible and should not be interrupted. Chest compressions should be one third deep, and the pressure should be fully released between compressions. Don’t stop if ribs break. 30:2 chest compressions to rescue breaths. After doing five cycles of continuous CPR, recheck for pulse and breathing. If the patient has a pulse but is not breathing, give rescue breaths. If the patient is breathing, keep their airway open. See the figures and tables below for how to modify CPR on children and infants. Stop CPR after 30 minutes normally, or 90 minutes if the patient was exposed to extreme cold.

  1. Position your hand. Kneel besides the patient and place the heel of your hand on the centre of the chest.
  2. Interlock fingers. Keeping your arms straight, cover the first hand with the heel of your other hand and interlock the fingers of both hands together. Keep your fingers raised so they do not touch the patient’s chest or rib cage.
  3. Give chest compressions. Lean forward so that your shoulders are directly over the patient’s chest, and press down on the chest about two inches. Release the pressure, but not your hands. Give 30 compressions at a rate of 100 compressions per minute.
  4. Give rescue breaths. Chin-lift/head-tilt the patient and let his mouth fall open slightly. Pinch the nostrils closed with one hand and support the patient’s chin with the other. Give 2 rescue breaths, removing your mouth from the patient’s to look along the chest making sure the chest falls.
  5. Continue CPR. 30 chest compressions, followed by two rescue breaths. Apply an AED to the patient as soon as possible, and continue CPR whenever otherwise.

Using a Defibrillator. The large majority of sudden cardiac arrests involve a shockable heart rhythm, so a defibrillator should always be used when a patient is in cardiac arrest. As soon as you determine that the patient is in cardiac arrest, deploy the defibrillator: If two responders are present, one responder should begin CPR while the second prepares the defibrillator and applies the pads to the patient. The unit will need to be activated, and the pads may need to be connected to the unit with electrical leads.

If available, select the most suitable pads for the patient (e.g., pediatric pads for a child). Pediatric pads are smaller and deliver a lower-intensity shock. If age-appropriate pads are not available, adult pads are acceptable. Defibrillation is not indicated for neonates (0 to 28 days old). Some defibrillators will detect the size of the patient and adjust the shock level automatically: Ensure that you are familiar with all the details of how your defibrillator works.

Activating the defibrillator as soon as cardiac arrest is confirmed allows the defibrillator to begin analyzing the patient immediately, and most defibrillators will also record the actions taken by responders and the times that they occur, creating a record of the treatment provided.

First, expose and prepare the patient’s chest. If it is wet, dry it quickly. If the patient has a large quantity of chest hair (enough that it interferes with the adhesion of the pads), quickly shave the areas where the pads will be affixed.

Attach the pads to the patient’s chest as directed by the defibrillator’s manufacturer. Most pads have illustrations showing the correct placement. Typically, one pad is placed on the upper-right side of the chest and the other on the lower-left side (figure 1 below). If the patient’s chest is too small to allow at least 2.5 cm (1 in.) of space between the pads, place one pad on the front of the patient’s chest (anterior) and one on the back (posterior).

The defibrillator may be used with standard defibrillation pads only on adults and children who are 8 years old or more or who weigh more than 25 kg (55 lb.). For children who are less than 8 years old or weigh less than 25 kg (55 lb.), use infant/ child reduced-energy defibrillation electrodes.

Pause CPR to allow the defibrillator to analyze the patient’s heart rhythm. Some devices do this automatically, and some (semi-automated defibrillators) require you to press an analyze button. To avoid interfering with the analysis, do not touch the patient or the defibrillator  while this analysis is performed (figure 2 below).  The defibrillator will notify you when the  analysis is complete. If the defibrillator detects a rhythm that indicates the need for a shock, ensure that no one is touching the patient and press the shock button. Compressions should be continued while the AED charges. The necessary interruption of CPR for the administration of a shock is referred to as the peri-shock pause. While it is crucial that no one touch the patient while the shock is administered, CPR compressions should be resumed immediately after the shock is complete. Continue CPR, listening for the defibrillator’s prompts.

If the defibrillator determines that no shock is advised, resume CPR and follow the defibrillator’s prompts, reanalyzing after 5 CPR cycles. If the defibrillator advises a shock and then later advises against a shock, this indicates that the patient’s condition has changed: Quickly reassess the patient before proceeding.

Defibrillator Care and Maintenance. You must ensure that your defibrillator is ready for use at all times. To arrive at the scene of a cardiac arrest with a defibrillator that is not functioning properly could result in the death of the patient.

At the beginning of each shift:

  • Ensure that the battery is fully charged. If possible, have a backup battery with you.
  • Ensure that all necessary components are with the unit.
  • Ensure that you have several sets of pads with you, including pediatric and infant pads (if available), and that they are within their expiration date.

Defibrillation Precautions.

  • Do not use a defibrillator in a moving vehicle. The motion of the vehicle can interfere with the defibrillator’s analysis of the patient’s heart rate, resulting in a shock being advised when it is not needed (or vice versa). Some modern defibrillators however are able to filter out external movement.
  • Do not defibrillate a patient in the presence of flammable materials. Do not use a defibrillator if materials such as gasoline are present. A defibrillator may produce a spark when the shock is delivered, which could ignite flammable materials. For the same reason, avoid using alcohol to clean the patient’s chest before applying the pads. You should also keep free-flowing oxygen away from the patient during defibrillation. Remove any oxygen-delivery devices while the shock is delivered, and use caution around oxygen in general.
  • Do not touch a patient while the shock is delivered. A defibrillator necessarily delivers a shock powerful enough to stop the human heart, so ensure that the electrical current travels through the patient only. Make sure that no one is touching the patient when a shock is delivered, and if the patient is touching a conductive surface (e.g., the metal frame of a stretcher), ensure that no one is touching that surface, either.

Special Resuscitation Situations

Pregnant Women. When performing CPR on a visibly pregnant woman, putting a blanket or cushion under her right hip will help blood return to the heart. However, do not interrupt CPR to find an object. It is safe to use a defibrillator normally on a pregnant woman.

Transdermal Medication Patches. A defibrillator pad should not be placed over a transdermal medication patch (e.g., nitroglycerin or nicotine), as the patch may block the transfer of the energy to the heart and may cause small burns on the skin. Remove any patches from the chest and wipe the area clean before attaching the electrode pads. Ensure that you are wearing gloves, as the medication in these patches is designed to be absorbed through the skin.

Implanted Pacemakers and Implanted Cardioverter-Defibrillators. A patient may have a pacemaker or cardioverter defibrillator (ICD) implanted in his or her chest. If you see a small scar and a matchbox-sized lump on the chest, ensure that the electrodes are positioned at least 2.5 cm (1 in.) away. If an ICD is already in shock sequence (e.g., the patient’s muscles contract in a manner similar to that observed during external defibrillation), allow 30 to 60 seconds for the ICD to complete the treatment cycle before delivering a shock from the external defibrillator.

Body Jewellery. If a piece of jewellery is within 1 inch of the defibrillator pad placement, remove the jewellery before applying the pad.

Trauma to the Torso. It is safe to perform CPR and place the defibrillator pads on the chest as usual if the trauma does not interfere with their placements.

Patients in Water. If the patient is in the water, remove them before defibrillation. A shock delivered in water could be conducted to responders or bystanders. Quickly wipe the patient’s chest dry and attach the defibrillator pads normally.

Rain or Snow. If it is raining or snowing, ensure that the patient is as dry as possible and sheltered from the weather. This should be done as quickly as possible: Throwing a tarp over yourself and the patient can provide the necessary shelter. If there is a safe, dry area nearby, consider moving the patient so long as it causes minimal delay. Wipe the patient’s chest dry. As always, follow all of the manufacturer’s precautions.

Neonatal Resuscitation. Resuscitation methods must be adjusted when the patient is a neonate (from birth to 28 days old). Because the cause of cardiac arrest in neonates is almost always respiratory in origin (not cardiac), there is more of a focus on ventilations. The ratio of compressions to ventilations is 3:1. Defibrillation is not indicated for neonatal patients.