How to easily distinguish between syncope, coma and shock? How to provide first aid on the spot?

Author: Jia Dacheng, first aid expert at Beijing Emergency Center

Reviewer: Wang Lixiang, Chief Physician, Third Medical Center, PLA General Hospital

Ordinary people often confuse fainting, coma and shock.

So, how do we differentiate between syncope, coma and shock? And how do we provide first aid?

1. What are syncope, coma, and shock? How to distinguish them?

Syncope is a brief loss of consciousness due to various reasons, which usually recovers in one or two minutes.

There are two major types of syncope: one is called simple syncope, accounting for more than 90% of the cases. There is no disease but there are triggers, such as standing for a long time, hunger, overwork, lack of sleep for a long time, and mental stimulation, which can all cause syncope; the other type is caused by various diseases, especially cardiac and brain-related syncope. These two types are very dangerous.

There may be signs before fainting, such as dizziness, palpitations, nausea, pale complexion, cold sweats, etc. Generally, the body gradually becomes weak and limp, and then falls to the ground.

Coma is caused by various reasons, which leads to extensive and severe inhibition of the cerebral cortex, mainly manifested as loss of consciousness and no response to various external stimuli. If the coma is relatively mild, pinching or pricking him may make him frown; if the coma is more serious, he will not respond to any stimulation, in layman's terms, he cannot be awakened.

If you suddenly lose consciousness and then wake up quickly, it is called syncope. If you don't wake up for a long time, it is called coma. The shortest coma time is tens of minutes or a few hours, and the longest coma may be decades, such as vegetative state.

Shock is a very urgent situation caused by a sharp decrease in blood volume in a short period of time due to various reasons, insufficient microcirculation perfusion, and a series of pathological damage to various tissues and organs. Many cases of shock are caused by a combination of reasons.

What are the causes of shock?

For example, hemorrhagic shock is caused by insufficient blood volume after massive bleeding, which leads to insufficient perfusion of all tissues and organs. It is a type of hypovolemic shock.

Hypovolemic shock also includes dehydration caused by sweating, severe vomiting, diarrhea, etc. Dehydration does not necessarily lead to shock, but shock definitely involves dehydration, and insufficient blood volume will lead to shock.

For example, anaphylactic shock. Drugs such as penicillin may cause anaphylactic shock. After taking the drug, the patient suddenly becomes pale, dizzy, has a drop in blood pressure, or even cannot be measured, and has a change in consciousness. Some patients will soon experience cardiac arrest after the shock, which is very dangerous. The mechanism of anaphylactic shock is very complicated. It is an allergic reaction that causes vasodilation.

What is more common now is cardiogenic shock, such as shock caused by myocardial infarction, arrhythmia, etc.

How is cardiogenic shock caused?

First, the myocardial contractility decreases, leading to a decrease in cardiac blood output; the severe pain caused by myocardial infarction causes reflex dilation of blood vessels. After the blood vessels dilate, the volume increases, but the blood does not increase, causing relative ischemia; rapid arrhythmia or slow arrhythmia can reduce cardiac blood output; in addition, vomiting and sweating can also reduce blood volume.

How can ordinary people judge whether someone is in shock?

Shock has two main characteristics: one is a drop in blood pressure, which may even be unmeasurable; the other is peripheral circulatory disorders, such as pale complexion, cold and clammy skin, etc.

In addition, due to different degrees of cerebral ischemia, consciousness may change to varying degrees. For example, the person may be confused at first, and then cannot be awakened and fall into a coma, which means that the cerebral ischemia is more serious. The pulse and respiration may be normal at first, but as time goes by, the pulse weakens or even cannot be felt. The breathing becomes shallow, slow, and irregular, which is quite serious.

2. How to provide first aid after fainting?

If you encounter a fainting spell, no matter what the reason is, you must prevent the person from falling. Lay the person flat immediately without putting anything under the head. If the person wakes up in one or two minutes, it is generally not a big problem.

Figure 1 Original copyright image, no permission to reprint

If you are still unconscious, you are in a coma. You should adopt a stable side-lying position to avoid suffocation and call emergency services immediately.

3. How to provide first aid after coma?

Adopt a stable lateral position, which is also called the recovery position or the restoration position. Try to let the patient lie on the right side. If environmental conditions do not allow, the left side position is also acceptable.

First, let the patient lie flat on the ground. The first aid personnel kneel or squat on the ground, lift the patient's right arm, put his left hand on his right shoulder, keep the hip and knee joints of the lower limbs flexed, and the first aid personnel hold the patient's left shoulder with one hand and the patient's left leg with the other hand. After fixing them, the patient is turned over and becomes a right-side lying position.

Figure 2 Original copyright image, no permission to reprint

Why do we need to lie on our side? First, the tongue will not block the airway. Second, if we vomit, we will not suffocate. In addition, the arm is under the neck, just like a pillow. This position is also more comfortable. Now this action is popular all over the world.

Also, be careful not to give the patient water or medicine to prevent suffocation. At the same time, call the emergency number immediately.

4. How to provide first aid after shock?

When encountering shock, different treatments should be taken immediately according to the different causes.

For example, in case of hemorrhagic shock, bleeding must be stopped immediately.

Bleeding can be divided into external bleeding and internal bleeding. If the internal organs such as the liver and spleen are ruptured, or if there are other reasons for internal bleeding, non-professionals will not be able to stop the bleeding on the spot.

If the bleeding is caused by trauma, such as knife wounds, car accidents, etc., it is relatively easy to deal with.

The first step is to take measures to stop the bleeding immediately. The second step is to let the patient lie flat. Because the blood supply to various tissues and organs is reduced, the brain is the most affected. The brain can tolerate ischemia and hypoxia for the shortest time, so the blood supply to the brain must be guaranteed first. After lying flat, gravity is overcome, and the blood supply to the brain can be relatively more.

It should be noted that you cannot put anything under your head and you should remove the pillow. If the head is higher than the chest, the blood supply to the brain will be reduced due to gravity, and the airway will be compressed, which will affect breathing. In addition to body position, you should also pay attention to keeping warm. Another important issue is to keep the airway open. After severe cerebral hypoxia and coma, the muscles of the whole body will relax, and the tongue will fall back, which can easily cause suffocation. If the patient vomits, you need to turn the head to the side immediately to prevent suffocation.

Figure 3 Original copyright image, no permission to reprint

While handling the situation, you must immediately call the emergency number. Ordinary people cannot do much on the scene. Professional personnel are needed to rush to the scene as soon as possible to provide professional treatment and send the patient to the hospital as soon as possible.