If you find an unconscious victim, call 911 and do not move him. You don’t know what happened to him, so moving him could aggravate his injury. Furthermore, if he isn’t breathing, then you don’t have much time to get help. When you call 911, see if the victim is breathing or not and if he isn’t, start rescue breathing.
AIRWAY
The letter “A” stands for AIRWAY. When a victim is unconscious and unresponsive, check his airway to make sure there are no obstructions. The victim’s breaths might be faint and shallow, so be careful when you look, listen, and feel for his breathing. If you find the victim has stopped breathing, he might have an airway obstruction. The tongue is the most common airway obstruction, but many other things can obstruct the airway too.
While the victim is lying on his back, gently tilt his head backwards. You can do this by putting one hand on his forehead and the other hand under his chin. This position causes the tongue to move and clear the airway. However, if the victim still isn’t breathing, you’ll need to help him breathe.
BREATHING
The letter “B” is for BREATHING. After clearing the victim’s airway, keep the victim’s head titled back and pinch his nose. This will prevent air from escaping as you place your mouth over the victim’s and begin ventilating.
Watch the victim’s chest as you give him air. Avoid overinflating his lungs as this will force air into his stomach, which could result in vomiting. If the victim vomits, simply turn his head to one side and carefully use your finger to sweep any new obstructions away before continuing.
At this time, you need to give the victim two full breaths. After each breath, give his lungs time to exhale and relax. If you put your ear near his mouth and listen, you may hear air escaping. While you do this, watch the victim’s chest and it should fall as his body exhales.
After these breaths, if the victim does not become responsive (e.g. if there is no breathing, moving, coughing, etc.), then you need to check his circulation.
CIRCULATION
The letter “C” in the A-B-C acronym is for CIRCULATION. Check and see if the victim’s heart is beating by locating the carotid artery. Use two fingers and put them on the victim’s neck like it shows in the picture to the right. Find the middle of the neck (where the Adam’s Apple is located on men) and slide your fingers to the side of the his neck and feel for a pulse.
If the victim has no pulse, it means his heart is not beating. This is when you should perform chest compressions.