American Heart Association's guidelines dictate that Adult CPR is performed on any person over the age of approximately 10 to 14 years (or post-adolescence, as defined by the presence of secondary sex characteristics).
Before you start any rescue efforts, you must remember to check the victim for responsiveness.
If you suspect that the victim has sustained spinal or neck injury, do not move or shake him. Otherwise, shake the victim gently and shout "Are you okay?" to see if there is any response. If the victim is someone you know, call out his name as you shake him.
If there is no response, immediately dial 911 and check the victim for circulation