If you have a crash or notice someone fainting in an emergency, check if they need CPR. Cardiopulmonary resuscitation is a life-saving technique, but it should only be performed when someone really needs it. To check if the person needs CPR, check the airway, breathing, and Microcirculation before starting.

Assess the situation. If you find someone collapsing or see someone fainting, please look around to see if you can reach them without compromising your safety. You should also check if he is in an area sufficient to move and assist you. If the person appears to be in immediate danger (such as in the middle of the street), please take them to a safe place before helping-but don't put yourself in danger. If you find yourself in a dangerous situation, you may also get injured. This can not only help the person you want to save, but also give rescuers another person to save.
If you suspect a neck or spinal cord injury, such as a person who fell from a height or a car accident scene with obvious signs of additional serious trauma, please be careful. [1] Anyone who falls from a height or gets involved in a motor vehicle accident should take precautions against the spine.

Talk to the victim. One of the best ways to check if someone is responding is to talk to her. "Are you okay?" There are also "Can you hear me? Also, pat her shoulder or arm while patting to see if it helps.
If this doesn't work, try yelling at her to see if it can wake her up. Shouting phrases like "Hey!" Or "Hello!" to see if she wakes up.
Rub the breastbone. Chest massage can help you make sure that the patient is not responding. You don't want to perform CPR on people who are slow to respond but are still breathing and circulating. Clench your fist and rub the person's sternum with your knuckles.
You can also try to "squeeze", grab the shoulder muscles with your thumb and fingers, and then squeeze the depression of the collarbone. When doing this, lower and listen for any sound or signs of breathing.
Anyone who is only numb but breathing needs to wake up in pain.
Please write down any reply to inform when the EMS will arrive.

Check the airway

Place the victims. The victim must be in the correct position before checking the airway. If there is an exudate (vomit, blood, etc.) in or around the person's mouth, please wear gloves and take off the gloves to clear the airway before rolling the person. Roll that person on her back. It should be on the surface as flat as possible so that her body can be straight and easy to use. Make sure that his hands are on his sides and his back and legs are straight.
Take a moment to gently press her shoulders down. This will increase the width of the trachea and help keep the jaws upward.

2 Move the head. To open the airway when lying on the floor, his head and airway must be aligned correctly. Place one hand behind the head and the other hand under the chin. Tilt your head to the sky.
The chin should end in a slightly raised position as if sniffing the air.

3 Remove foreign bodies from the respiratory tract. There may be airway obstruction. This may come from a foreign body, the victim's tongue, vomit, or other body fluids. If the airway is obviously blocked by vomit or other movable materials, use two or three fingers to quickly slide in the mouth to remove it from the mouth. You can quickly turn the victim's head to the side to aid removal.
Try to avoid wiping the open mouth to avoid pushing the substance further into the trachea. Instead of digging, use sweeping action.
If the tongue is blocking the airway, try the jaw thrust method. Bend down and look at the toes. Grasp the chin gently but firmly with both hands so that the fingers are bent into the soft flesh of the chin. Gently lift your chin into the air without moving the rest of the head. This helps to make the tongue fall to the bottom of the chin instead of in the airway.