How to use AED and seize the golden 4 minutes of "sudden death rescue"?

On the evening of June 30, a young athlete from the Chinese badminton team suddenly fell to the ground and convulsed during a competition in Yogyakarta, Indonesia, and died after being sent to the hospital. According to current information, the athlete's death was most likely caused by sports-related sudden cardiac death .

Sudden death refers to acute symptoms caused by various reasons, usually within 1 hour. Among the causes of sudden death, sudden cardiac death is the most common, accounting for more than 80% of the total number of sudden deaths. According to data from the National Center for Cardiovascular Diseases, more than 540,000 people die of sudden cardiac death in my country each year.

Sudden death rescue, time is life

Image source: Tencent @心内科阳地黄

A "life-saving artifact" called AED is the key to grasping the golden time for rescue.
It can be seen in public places such as subway stations, schools, large shopping malls, swimming pools, etc.

On the wall of the corridor of Lujiazui subway station

Image source: csgy.rmzxb.com.cn

Shopping mall AED

Source: Xinmin Evening News

Of course, we also have it in Shanghai Science and Technology Museum~

AED at Shanghai Science and Technology Museum before renovation

AED boxes in different regions look slightly different. For example, Shenzhen has green ones and Beijing has orange ones.

AED in Shenzhen subway station

Image source: Shenzhen Metro

AEDs in Beijing subway stations

Image source: Xinhua News Agency

In Shanghai, there are 10.8 AEDs for every 100,000 people. You can search for nearby AEDs through the "Service Hall" column of the WeChat public account "Shanghai Red Cross Service Account".

Image source: Shanghai Red Cross Service Number

The full name of AED is automatic external defibrillator . Why is it called this name? We need to first understand cardiac arrest.

When it comes to cardiac arrest, many people think that the heart suddenly stops moving. In fact, this is not the case.

In most cases of cardiac arrest, the electrical activity of the heart muscle cells is unsynchronized and irregular , which causes the heart's contraction to be in a similar chaotic state and unable to effectively pump blood to the body.

Medically, this activity is called " ventricular fibrillation " and " pulseless ventricular tachycardia ". If it lasts for more than 4 minutes, the brain will suffer irreversible damage due to lack of fresh blood supply.

You can see how chaotic the heart's electrical activity is during ventricular fibrillation.

Image source: nursingtimes.net

For ventricular fibrillation, the most effective first aid is early electric shock defibrillation . For every minute of delay in defibrillation, the success rate of first aid will drop by 7% to 11%. If cardiopulmonary resuscitation and electric shock defibrillation are not performed in time, the patient's chance of survival will be lower.

The function of AED is to terminate the irregular heartbeat activity and make it regular through a powerful electric shock ; instead of changing the patient's electrocardiogram from a straight line to a fluctuating line as shown in TV dramas.

Usually, one electric shock cannot completely stop the chaotic activity of the heart, so continuous and effective cardiopulmonary resuscitation (CPR) is needed to maintain basic blood circulation and wait for the heart to resume regular beating on its own.

Image source: CCTV News

AED is easy to operate and comes with a simple and easy-to-understand operating guide. But it should be emphasized that when using an AED, chest compressions must be maintained until the AED prompts you to stop!

Step 1: Turn on the power (maintain chest compressions)

After turning on the power, the AED will start voice prompts.

Step 2: Apply electrode patches (maintain chest compressions)

Remove the patient's clothes to expose the chest. Stick two electrode patches on the skin below the left nipple and above the right nipple, and connect the electrode patches to the AED.

Image source: fda.gov/consumers

It should be noted that if the patient's chest skin is very moist, it should be simply wiped dry first (not completely dry); if the patient's chest hair is particularly dense and the patch cannot stick tightly to the skin, the patch should be torn off forcefully to remove the chest hair, and then a new patch should be applied to the skin.

Step 3: Prepare for shock (stop chest compressions)

After the electrodes are properly attached, the AED will automatically analyze the patient's heart rhythm and prompt you to stop compressions. At this time, you should stop chest compressions and do not touch the patient to avoid interference.

Image source: CCTV Video

After the analysis is complete, the AED will voice prompt whether to recommend an electric shock. If not, continue chest compressions; if it is recommended, immediately remind everyone not to contact the patient (otherwise you will get an electric shock), and then press the shock button.

Step 4: Repeat (continue chest compressions)

Do not remove the patch and continue chest compressions immediately until the AED automatically analyzes the heart rhythm again and prompts you to stop compressions (usually automatically analyzes once every 2 minutes).

Image source: CCTV News

Learning first aid knowledge such as the use of AED is not only to save the lives of others, but also to enable yourself to get timely assistance in times of crisis.

Please bookmark and share this article to help popularize the use of AED and build a protective barrier for the life safety of yourself and those around you!

Author: Zhu Renqing, MD, neurosurgeon at the Children's Hospital of Fudan University. Editor: Xiao Dingdang, Xiao Xiao Dandelion