Check the victim for unresponsiveness. If the person is not responsive and not breathing or not breathing normally. Call 911 and return to the victim. If possible bring the phone next to the person and place on speaker mode. In most locations the emergency dispatcher can assist you with CPR instructions.
If the victim is still not breathing normally, coughing or moving, begin chest compressions. Push down in the center of the chest 2-2.4 inches 30 times. Pump hard and fast at the rate of 100-120/minute, faster than once per second.
Tilt the head back and lift the chin. Pinch nose and cover the mouth with yours and blow until you see the chest rise. Give 2 breaths. Each breath should take 1 second.
CONTINUE WITH 30 PUMPS AND 2 BREATHS UNTIL HELP ARRIVES
NOTE: This ratio is the same for one-person & two-person CPR. In two-person CPR the person pumping the chest stops while the other gives mouth-to-mouth breathing.