Civilian CPR - Adult
When a you see a person laying on the ground, we can almost guarantee that your initial reaction will not be, "Oh my God, that person is dead, and needs CPR." A more realistic response would be, "Why is that person laying on the ground?" And that is actually a much better place from which to start, because it keeps open the possibility that this person may indeed just be sleeping. It is a perfect "lead-in" to the first step in any CPR event. That is to establish unresponsiveness. And so, you should tap the victim on the shoulders and shout, "Hey, hey, are you okay?" If the person does not respond, you need to immediately activate the Emergency Medical Services (EMS) System. This means that, if necessary, you should leave the patient, go to the nearest phone, and call 9-1-1. Hopefully, someone else will be standing around, and you can send them to make the telephone call for you. Be sure to instill in them a sense of importance by asking them to come back and let you know that the call has been made ("You! Go call an ambulance for an unresponsive adult. Then come back and let me know that the call was made.")
Once the EMS system has been activated (or you've sent this "helper" on his way to the nearest phone,) you should first position the patient on his/her back, then check the ABC's of CPR.
A - Airway This means positioning the patient's head so that it is hyperextended, by tilting the head and lifting the chin. If there is a chance that the patient has a neck injury, then the rescuer should guard against further injury by modifying the procedure. Instead of a head tilt with a chin lift, the rescuer should perform a modified jaw thrust, where the jaw is displaced anteriorly (in this case - upwardly) without moving the neck.
B - Breathing The rescuer should check to see if the patient is breathing. This is done by the Look, Listen, and Feel method. Look at the chest to determine if it is moving. Listen for the sound of air moving in and/or out of the nose and mouth. Feel for the movement of air from the nose and/or mouth. If this adult patient is not breathing, then the rescuer should ventilate the patient (mouth-to-mouth or mouth-to-mask) about 12 times a minute, or once every 5 seconds. If the patient is breathing, the rescuer should roll the patient into the recovery position. Once in the recovery position, monitor the patient's breathing to be certain that it is adequate. (see below)
C - Circulation The rescuer should check for signs of circulation (breathing, coughing, eyelid flutter, movement, and if trained to do so, the presence of a pulse.)
Our assumption at this point will be that we have a patient that is not exhibiting any "signs of circulation." Position the patient on his/her back. Applying an Automatic External Defibrillator (AED,) if available, might be appropriate, if the rescuer is properly trained and if the rescuer is certain that the patient is without a pulse (merely checking for the other "signs of circulation" would not be enough.) In lieu of the AED, the rescuer should initiate the CPR process by first assuring patient's head is in a position of hyperextension. Ventilate the patient twice (as explained in the "Simple CPR" section,) if the ventilations do not seem to be "going in," reposition the head and try again Once you have successfully ventilated the patient, position your hands (one on top of the other) over that portion of the patient's chest where you would expect to find the heart (generally, between the nipples on the chest of a man, or an equivalent position on the chest of a woman.) You are going to push the breastbone down toward the patient's back and "squeeze the heart between the breastbone and backbone. To do this the breastbone must be displaced approximately 1 to 2 inches toward the backbone. From this point the rescuer will do a combination of ventilations and compressions (Two  ventilations after thirty  compressions) for about two minutes (or five  cycles of ventilations and compressions,) at a rate of about 100 times per minute. Don't be surprised if you hear/feel some 'snapping or crunching' when you do that first compression. The likelihood is that you are disconnecting the ribs from the cartilage that connects them to the sternum (or maybe you just busted some ribs.) If you hear or feel any 'uncomfortable' sensations as described above, just be certain that you are in the right location, and continue with CPR. If necessary, we can 'fix' the ribs later. What we CAN'T do is 'fix' DEAD later.
After about two minutes of CPR, the rescuer should check for return of "signs of life" (including breathing.) If none, continue CPR. If the patient exhibits some signs of life, make sure that the patient is breathing at an appropriate rate (about 12 times per minute or once every 5 seconds for an adult patient.) If the patient is not breathing or is breathing inadequately, then the rescuer should perform rescue breathing to assure that the patient is ventilated once every 5 seconds.
If the patient is breathing adequately, he/she must be placed in the recovery position, and the patient's breathing should be monitored (one breath every 5 seconds) until you are relieved.