Sudden cardiac arrest is the unexpected and complete cessation of effective heart activity with presence or absence of bioelectrical activity.
Cardiac arrest or, as doctors would say, “the state of clinical death”, may occur as a result of accidents (e.g. serious injury, drowning, electric shock or lightning, severe poisoning, etc.) or as a result of various severe diseases (such as acute myocardial infarction, cardiac arrhythmias, thromboembolism, respiratory failure and other terminal conditions). The state of clinical death usually lasts 4 to 5 minutes, after which irreversible changes begin to develop in the body of the victim, against which medicine is powerless (biological death).
The symptoms of cardiac arrest are: loss of consciousness, absence of pulse on large vessels, including the neck, cessation of spontaneous breathing, sudden blanching of the skin, occurrence of rare convulsive breaths, dilated pupils and their lack of response to light.
External cardiac massage and artificial respiration should not be performed if the victim is unconscious but breathing and the heart still works.
Artificial respiration cannot be performed in case of an open chest injury or in case of suspicion of ribs fracture, as blood vessels may be injured, thus increasing bleeding.
Clinical death first-aid (cardiopulmonary resuscitation measures or CPR) includes external cardiac massage and artificial respiration (2 breaths at every 30 cardiac compressions). The majority of cardiac arrests involve ventricular fibrillation, which can be suppressed by electrical defibrillation with an automatic external defibrillator at the hospital. The probability of successful defibrillation decreases with time, by approximately 2-7% every minute, but first aid measures slow down this process, delaying the development of asystole (absence of cardiac electrical activity).
The signs of correct performance of chest compressions and of artificial respiration are the narrowing of the pupils and appearance of their response to light.
If resuscitation actions prove successful, the victim must be taken to the hospital, taking special care as there may be repeated respiratory and cardiac arrest (in this case, all resuscitation measures would have to be repeated).
Cardiopulmonary resuscitation steps:
- The victim is placed with the face up on any smooth, hard surface (soft surfaces reduce the effectiveness of chest compressions). A roll must be placed under the shoulders to allow holding up the head and prevent the obstruction of airways with the tongue, which also impedes performance of artificial respiration. If possible, the victim’s legs should be lifted about 0.5 m up, in order to ensure a better blood flow to the heart from the lower body. Any constraining body clothes must be quickly removed to reveal the chest. Taking off the victim’s clothes is an unjustified waste of time, therefore not advisable.
- The person providing assistance must be situated on the left side of the victim, with his/her hands placed one on the other on the lower third of the chest, performing a rhythmical pressing on it (one compression for 2 seconds). In this way, the victim’s heart is squeezed between the thorax and the spine, and the blood is ejected from the cavities of the heart into the blood vessels; in the interval between the pressings, the heart is passively straightened and filled with blood. This is enough for the blood to be supplied to all body organs and tissues and to maintain the victim’s life. Massage movements should be quite vigorous but not rough; the thrusts of the rescuer should be made with the straightened arms, using the weight of his/her body (sternal compression with the force of the arms is inefficient, as it quickly leads to rescuer’s exhaustion). The lower part of the victim’s sternum should bend with 3-4 cm, and in overweight people — 5-6 cm. The ends of the lower ribs shouldn’t be pressed on, as this may cause their fracture. After each compression, hands should be held in the position reached for about one-third of a second, in order to allow the chest to straighten without taking off the hands. Compressions must be performed approximately once per second or more often. At a lower rhythm the blood flow created is not sufficient. A break of 2-3 seconds should be made after every 30 compressions. If assistance is provided by two people, the second rescuer shall perform artificial respiration during this time. If assistance is provided by a single person, it is recommended to alternate the measures as follows: after two quick insufflations of air into the lungs 30 chest compressions must follow, with an interval of 1 second. External cardiac massage should be performed until regular pulse appears. The pulse should be checked during the 2-3 second pause while blowing air into the lungs. It is preferable to determine the pulse at the site of the carotid artery. While performing the external cardiac massage it is worth remembering that, in a state of clinical death, due to a sharp decrease of muscle tone, the chest has an increased mobility. Therefore, the person providing assistance should act carefully, without panicking. A forceful type of massage could lead to fractured ribs and sternum. If assistance is provided by two people, the more experienced of the two should perform the cardiac massage, and the second rescuer should provide artificial respiration.
- Cardiac massage is practiced simultaneously with artificial respiration. For this purpose, it is necessary to stand up to the right side of the victim, to take the right hand under his neck, to impose the left one on the forehead and to tilt the head back at a maximum so that the chin is in line with the neck (usually when tilting the head back the victim’s mouth will spontaneously open). The mouth and nose of the victim are cleared from any blood, mucus, foreign bodies or liquids, dentures are removed (with gauze, handkerchiefs, etc.). Often these operations are enough to restore spontaneous breathing.
- After clipping the victim’s nose and after a deep inhale, the mouth of the rescuer is pressed tightly to the victim’s open mouth, forming a seal, and a strong exhale is made into the mouth of the victim (mouth-to-mouth respiration). Artificial respiration can be performed by another method: by holding the victim’s mouth and blowing air through the nose (mouth-to-nose respiration). Artificial respiration is effective when the victim’s respiratory movements of the chest reappear in the same rhythm with air insufflations. Artificial respiration can also be given through a handkerchief or several layers of gauze. About 12-15 breaths should be provided in a single minute; the volume of the injected air must be of 1-1.5 liters. Exceeding the recommended amount of blowed air at one time can cause pulmonary barotrauma. According to the American Heart Association (AHA, 2010), when performing CPR, artificial respiration may not be provided, especially if there is only one rescuer or for hygienic reasons. Instead, chest compressions must be applied, since this measure is more important for the sufficient blood and oxygen supply to the victim’s brain. In this case, the person performing cardiac massage must perform 70–100 chest compressions per minute in a continuous way.
- Massage movements and artificial respiration require physical strength and endurance; therefore the persons providing assistance should change places every 5-7 minutes.
- If there are three persons surrounding the victim, the two most enduring ones should begin performing artificial respiration and chest compressions, while the third person should call an ambulance and help deliver the victim to the hospital.
- Resuscitation measures must continue until professional help arrives or the victim regains consciousness, provided that the rescuer is not tired and is able to continue resuscitation. Resuscitation measures may be stopped if the surroundings become unsafe and the rescuer must leave the site/location, or if the last person becomes too exhausted to continue and cannot change places with someone else.
- Chest compressions and artificial respiration must not be interrupted during the way to the hospital. Once arrived at the hospital, advanced resuscitation measures will continue, including defibrillation and intravenous administration of all required drugs.
In some cases, sudden cardiac arrest can be reversible, if the resuscitation measures were applied correctly and in time. Otherwise, when untreated or when the victim’s body doesn’t respond anymore to the measures performed, it may cause death within minutes. It is very important for the person performing the first aid in cardiac arrest to stay calm and self-confident for the maximal and quick use of his knowledge and forces. It is also important for every person to know what CPR measures in cardiac arrest imply, so that, in case of an emergency, someone’s chances to survive can increase.