A person needing CPR will be collapsed on the ground, completely unresponsive, not breathing, and have no pulse.
To determine if a person needs CPR the first thing to do is go over and slap them on the shoulders to try waking them up. Be forceful; make sure they aren’t simply unconscious or semiconscious.
If they don’t show any sign of life immediately call 911, then check to see if they’re breathing.
Tilt the person's head back by lifting their chin, and put your ear close to their nose and mouth to listen for breathing sounds. As you do this look at their chest to see if it rises and falls. Do this for no more than 10 seconds to make sure they’re not breathing.
It is unnecessary to check for a pulse for 2 reasons.
The pulse can be weak or difficult to find.
The person may be unconscious due to choking. In this case the proper treatment is CPR. See the section on choking below for more information.
How to Perform CPR
Before giving CPR check for severe bleeding. If the patient has major bleeding, CPR will only push more blood out of their body. Hemorrhage must be controlled before starting CPR.
After determining that the person needs CPR, roll them onto their back and begin chest compressions by kneeling to one side of the torso and placing the heel of one hand in the center of their chest right between the nipples.
Place the heel of your 2nd hand on top of the first one and interlock your fingers.
Lock your elbows straight and position yourself so you’re pushing straight down. Push hard and fast, keeping a pace of at least 100 beats per minute (bpm). For reference, the choruses to Stayin' Alive by the Beegees and Another One Bites the Dust by Queen are both 100 bpm.
Give 30 chest compressions counting out loud and pushing at least 2 inches deep on every compression.
Stop compressions to give 2 rescue breaths.
Tilt the head back, and lift the chin up.
Pinch the nose so that the air goes into their lungs and blow into their mouth for about 1 second making sure that the chest rises. If you have a disposable face barrier, place it as shown by the pictographic instructions on the barrier. If you have a pocket mask, you don’t have to pinch the nose since the mask covers both the nose and the mouth. 5 cycles of breaths and compressions should take 2 minutes.
Repeat the cycles of compressions and breaths until one of these things happens:
The person shows signs of life, like breathing.
Another trained responder shows up and takes over.
An AED is ready to use.
CPR for Choking Victims
If the patient is conscious and choking, perform the Heimlich maneuver. See here for more details.
If the patient is unconscious due to choking, CPR can clear their airway. Administer compressions and breaths as normal until the person shows signs of life, a trained responder shows up and takes over, or an AED is ready to use.
If the patient drowned, it may also be helpful to lower the head below the lungs to drain the water while you perform CPR.