What is a cardiac arrest?

What is a cardiac arrest?

Sudden cardiac arrest is one of the most critical medical conditions. It manifests as a sudden stop of the heart beat. The patient does not respond to stimulation, no pulse, no spontaneous breathing, or only near-death wheezing. If timely and effective treatment is not available, immediate death often results in immediate death. . Many patients lost their lives or died prematurely because they were not rescued by resuscitation.

　　Modern medicine has not fully grasped the occurrence of cardiac arrest, so it is impossible to accurately predict which patients will have cardiac arrest. Patients with coronary heart disease (acute myocardial infarction, unstable angina pectoris), severe arrhythmia, decreased cardiac function, etc. are at high risk of cardiac arrest. The incidence of cardiac arrest is 5 to 10 times higher than that of the general population, but there are still Many patients with sudden cardiac arrest have no medical records due to physical discomfort during their lifetime, so cardiac arrest is still a serious public health problem worldwide.

　　The incidence of sudden cardiac arrest is difficult to count accurately. The total number of sudden cardiac arrests in the United States is about 300,000, and most of them occur outside the hospital. The annual incidence of cardiac arrest in China is 41.84/100,000, and the incidence rate is about 0.04%. Based on the 1.3 billion population, the total number of cardiac arrests is 544,000, which ranks first in the world, which means that every minute One person had a cardiac arrest. With the intensification of the aging population in my country, the number of patients with chronic cardiovascular disease is increasing, and the total number of patients with cardiac arrest will further increase. As far as the prevention of sudden cardiac arrest is concerned, the risk factors for sudden cardiac arrest such as smoking, hypertension, obesity, hyperglycemia, and hyperlipidemia are far from being controlled. The onset and management of cardiovascular diseases are not good. The preventive measures for suspension are still very different from the international level.

　　Sudden cardiac arrest can occur at any age, with a high incidence of elderly people over 60 years old, more men than women, but infants and children can also have cardiac arrest. Estrogen has physiological protection against cardiac arrest. Women are protected by estrogen before menopause and are not susceptible to coronary heart disease. Therefore, in young and middle-aged people, the probability of male cardiac arrest is 4-7 times that of women . The risk of cardiac arrest in women after menopause is gradually equal to that of men.

　　The most common cause of cardiac arrest is heart disease, especially coronary heart disease; others include non-cardiac causes such as trauma, drowning, overdose, and asphyxia. The main causes of cardiac arrest in children are non-cardiac. Meilun includes respiratory diseases (such as airway obstruction, smoke inhalation, drowning, and infection), poisoning (including overdose), and neurological diseases.

　　Sudden cardiac arrest is different from heart attack. During sudden cardiac arrest, abnormal heart rhythm causes the heart to vibrate, and the heart cannot pump blood to the brain, lungs, and other organs. When a heart attack occurs, blood flow to part of the myocardium is blocked by a thrombus, causing myocardial necrosis in the blocked area. Most heart attacks do not cause cardiac arrest, but heart attacks are a common cause of cardiac arrest.

　　Many patients may have prodromal symptoms, such as angina, shortness of breath, or increased palpitations, prone to fatigue, for days, weeks, or even months before cardiac arrest occurs. Acute changes in cardiovascular function can occur when cardiac arrest occurs. Typical symptoms include: persistent angina or acute chest pain, acute dyspnea, sudden palpitations, continuous tachycardia, and dizziness. If a sudden cardiac arrest occurs instantaneously without warning, 95% is cardiogenic and has coronary artery disease.

The vital signs of patients with sudden cardiac arrest under witnessing generally have the following manifestations: (1) Sudden loss of consciousness or accompanied by brief convulsions, convulsions are often systemic, mostly within 10 seconds after cardiac arrest, and sometimes with eye deflection; (2) The pulsation of the aorta (carotid artery or femoral artery) disappeared; (3) The breathing was interrupted, sighing, and then stopped. It mostly occurs within 20-30 seconds after cardiac arrest; (4) Mydriasis. With the help of (1) and (2), the occurrence of cardiac arrest can be basically determined. Although mydriasis is an important indicator of cardiac arrest, the response is delayed and susceptible to factors such as drugs, so you should not wait for the pupil to change It was determined to be a cardiac arrest. The assessment of vital signs in patients with cardiac arrest should be rapid and accurate.

The success rate of cardiopulmonary resuscitation outside the hospital in my country is extremely low, still staying at 1.2% to 1.4%. When sudden cardiac arrest occurs, the popularity and training of the CPR rescue process is still far from public awareness. Although the automatic external defibrillator (AED) has been installed in public places, the actual utilization rate is still very low. Due to the limitation of the allocation of emergency resources, the time for professional emergency personnel to call for help to reach the scene is more than 10 minutes on average, often missing the best "golden time" for emergency cardiac arrest. If CPR is not given within 4 to 6 minutes, the prognosis is poor. If cardiopulmonary resuscitation is not given within 8 minutes, unless there are special circumstances such as low temperature, there is little chance of survival.

　　 Early treatment, time is life. Cardiopulmonary resuscitation (CPR) is a series of life-saving actions that improve the chance of survival after cardiac arrest. The cardiopulmonary resuscitation process particularly emphasizes the prime time for the start of treatment: that is, cardiopulmonary resuscitation should be given within 4 minutes after the occurrence of cardiac arrest. Only 3 to 4 minutes of hypoxia can cause irreversible fatal damage to the brain. Studies have shown that from the time of cardiac arrest to the time of the first shock <4 minutes, the survival rate of patients can be as high as 60% to 75%, and those who receive effective treatment (electrodefibrillation and effective cardiopulmonary resuscitation) after a long period of time are treated. The success rate is only 15%. In the implementation of delayed defibrillation, timely, standardized and effective cardiopulmonary resuscitation is more important. Meilun can partially relieve the hypoxic state of the heart and brain ischemia caused by the cardiac pumping pause during the duration of ventricular fibrillation, and lengthen the effective treatment time. . For patients with sudden cardiac arrest outside the hospital, if they can receive cardiopulmonary resuscitation in time, the survival rate can be increased by 2 to 3 times.

　　Every minute the defibrillation is delayed, the survival rate is reduced by 7%-10%

　　 Although factors such as rescuers, patients, and available first-aid resources affect the implementation of optimal CPR, the basic problem of how to implement effective CPR as early as possible remains. The key to implementing CPR is to identify patients with cardiac arrest as early as possible, and to act quickly and decisively.