First, the cause of sudden death
Internal cause refers to the latent disease, disease outbreak, abnormal constitution and allergic constitution in the main organs of human beings. Sudden death accounts for about half of all acute deaths; It accounts for 10%~ 15% of all natural deaths. For adults, sudden death caused by cardiovascular diseases ranks first, followed by respiratory diseases and central nervous system diseases; Children with respiratory diseases account for the vast majority. Although there are various organic diseases leading to sudden death, the causes leading to the final death of patients can be summarized as: cardiac arrest, acute heart failure, shock, acute respiratory failure, acute liver failure or renal failure, and brain death.
In all kinds of situations, such as laughing, watching movies, listening to stories, quarreling, drinking, eating, urinating, bathing, having sex, walking, cycling, working, smoking, sleeping, etc., sudden death may occur. Most of them died outside the hospital, and a few died in the emergency room or hospital.
Second, common incentives.
Mental factors play an extremely important role in the inducement of sudden death. Such as carnival, anger, tension, fear and other emotional excitement or when people feel pain, the cerebral cortex will form too strong excitement focus, which can excite the cardiac acceleration center and vascular center of the medulla oblongata and obviously enhance sympathetic-adrenal activity. At this time, sympathetic nerve activity is dominant, not only the nerve medium norepinephrine released by sympathetic nerve endings increases, but also the amount of adrenaline secreted into the blood by adrenal medulla greatly increases. Under the action of sympathetic nerve and adrenaline, on the one hand, cardiac contraction is strengthened and accelerated, and cardiac output is increased; On the other hand, the small blood vessels in most areas of the body contract and the peripheral resistance increases, so the blood pressure rises rapidly.
However, some patients are just the opposite when they are excited. The excitability of the cardiac inhibitory center in the medulla oblongata is enhanced, and the vagus nerve is dominant. The neurotransmitter acetylcholine released by vagus nerve endings increases, which leads to slow and weak heart rate, decreased cardiac output, decreased blood pressure and even cardiac arrest.
The human body changes caused by emotional excitement may not have serious consequences for ordinary healthy people, but those with potential lesions such as cardiovascular, lung, brain and endocrine organs may have a certain degree of adverse effects and even lead to death. Sudden death caused by mental factors and pain is caused by ventricular fibrillation or ventricular arrest caused by nerve reflex.
During strenuous physical activity or excessive fatigue, muscles, tendons, joints and other receptors emit a large number of impulses, which are introduced through sensory nerves, so that the excitability of cerebral cortex increases, the excitability of sympathetic nerve increases correspondingly, and the excitability of parasympathetic nerve decreases. Sympathetic nerve excitation promotes adrenal medulla to secrete more adrenaline and norepinephrine. Under the action of sympathetic nerve and adrenal medullary hormone, cardiovascular function can undergo a series of changes, mainly manifested as accelerated and strengthened heartbeat, increased cardiac output and increased arterial pressure.
In addition, the metabolism of muscle substances is enhanced, and metabolites such as carbon dioxide and lactic acid are accumulated, which consumes a lot of oxygen and nutrients and produces excessive fatigue. Intense physical activity or excessive fatigue is very dangerous for people suffering from coronary artery stenosis, coronary atherosclerosis, coronary thrombosis, aneurysm, hypertension, myocardial infarction, myocardial hypertrophy, myocardial fibrosis, severe myocarditis and valve deformation, which may lead to decreased blood volume in cardiopulmonary circulation, myocardial hypoxia and cardiac insufficiency due to blood circulation disorder; Or cause arterial rupture and hemorrhagic shock; It may also cause cerebral artery rupture, leading to death from cerebral hemorrhage.
Nicotine is absorbed when smoking, which can lead to increased heart rate, spasm of peripheral blood vessels and coronary arteries, slight increase of blood pressure and slow down of coronary blood flow. In addition, the carbon monoxide produced during smoking changes hemoglobin into carbon monoxide hemoglobin, which affects the oxygen carrying capacity of red blood cells, thus causing myocardial hypoxia. Heavy smoking can make the content of carbon monoxide and hemoglobin in blood as high as 15%. Therefore, smoking is very harmful to patients with coronary heart disease and heart disease, and may even induce cardiac arrest and sudden death.
The main function of drinking alcohol is to inhibit the function of the higher center of cerebral cortex. After the inhibition of higher central function, it can lead to paralysis of respiratory and circulatory centers in subcortical medulla oblongata. For people with heart, blood vessels, lung, brain, liver, kidney and other diseases, drinking alcohol can easily lead to the failure of these organs, and also lead to blood vessel rupture and bleeding and death.
Trauma or infection generally refers to minor trauma or infection. Although they are not directly fatal, they will worsen the original lesions and lead to death. Mild infection can reduce the patient's resistance again, and promote the onset or aggravation of the original underlying disease and sudden death.
Other factors, such as overheating and overeating, may sometimes be the cause of sudden death.
To sum up, the main cause of sudden death is internal cause, that is, there are potential diseases or fulminant diseases in the body. Motivation works through internal factors. Some inducements do little or no harm to truly healthy people, but for people with underlying diseases, physical abnormalities or allergies to some major organs, they will lead to rapid aggravation of internal diseases and even death. However, there are also cases of sudden death under quiet conditions without incentives such as rest and sleep. Therefore, when judging the cause of death, we must correctly analyze the relationship between internal causes and incentives in order to better guide clinical work.
Third, the common primary diseases leading to sudden death
Heart disease and coronary heart disease are the most common causes of sudden death in the elderly. Literature shows that the average incidence of sudden death of coronary heart disease in China is 28.7/65438+ 10,000, accounting for 45. 1% of the total mortality of coronary heart disease. The main coronary artery or its branches of some deceased people are often seriously blocked, which is usually not paid enough attention or limited by medical conditions. Many people have hardly had ECG or coronary angiography without diagnosis, and the disease has not been treated in time and effectively. After acute large-scale myocardial infarction, it is often easy to lead to sudden death under some incentives. In addition, other heart diseases, such as myocardial ischemia, aortic dissection aneurysm, aortic valve stenosis and malignant arrhythmia, are also the causes of sudden death.
Due to the continuous improvement of examination methods and the autopsy of the deceased, the incidence of pulmonary embolism has become higher and higher in recent years, which plays an important role in the etiology of sudden death in the elderly. Because most elderly people have hypercoagulability, a considerable number of patients have varicose veins, phlebitis or thrombosis of lower limbs. Some people stay in bed for a long time due to illness, with little activity, and are prone to pulmonary embolism. Once the pulmonary artery is blocked, it will have fatal consequences and the success rate of rescue is low.
Cerebrovascular diseases are mainly cerebral hemorrhage. The vast majority of patients with cerebral hemorrhage have vascular diseases, and hypertension, diabetes and atherosclerosis are common causes. Under the bad stimulation of emotional excitement, alcohol and tobacco, blood pressure can often rise sharply and blood vessels rupture. A small amount of bleeding can be rushed to the hospital for treatment, which can save lives. However, many patients will die quickly because of the large amount of bleeding, forming brain hernia and oppressing the life center. Therefore, once the patient has symptoms such as headache and nausea, it must be taken seriously.
In digestive tract diseases, hemorrhagic necrotizing pancreatitis leads to more sudden death, and upper gastrointestinal bleeding can also lead to sudden death. Patients with gastrointestinal bleeding usually have a history of potential esophageal varices, peptic ulcer, massive medication or stress. Shock caused by sudden bleeding at night or suffocation caused by vomit blocking the throat are often the main causes of sudden death caused by upper gastrointestinal bleeding.
Sudden death at night caused by severe hypoglycemia in elderly diabetic patients is also common. The reason is that a considerable number of elderly diabetic patients have not received formal treatment, or have not eaten in time after receiving hypoglycemic drugs; The blood sugar level of some patients changes greatly, and hypoglycemia often occurs at night.