The American Heart Association has issued new CPR guidelines, recommending that when attempting life-saving efforts for adults and children, start with chest compressions—"push hard and fast"—before doing mouth-to-mouth resuscitation. As the AP reports, "The change ditches the old “ABC” approach - “A” for airway, “B” for breathing, “C” for compressions. That called for rescuers to give two breaths first, then alternate with 30 presses. Under the revised guidelines, rescuers using traditional cardiopulmonary resuscitation should start chest compressions immediately - 30 chest presses, then two breaths."
The AHA 2010 Guidelines (PDF) explains why they are recommending chest compressions first, "Most victims of out-of-hospital cardiac arrest do not receive any bystander CPR. There are probably many reasons for this, but one impediment may be the A-B-C sequence, which starts with the procedures that rescuers find most difficult, namely, opening the airway and delivering breaths. Starting with chest compressions might encourage more rescuers to begin CPR." Also:
The vast majority of cardiac arrests occur in adults, and the highest survival rates from cardiac arrest are reported among patients of all ages who have a witnessed arrest and an initial rhythm of ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT). In these patients, the critical initial elements of BLS are chest compressions and early defibrillation. In the A-B-C sequence, chest compressions are often delayed while the responder opens the airway to give mouth-to-mouth breaths, retrieves a barrier device, or gathers and assembles ventilation equipment. By changing the sequence to C-A-B, chest compressions will be initiated sooner and the delay in ventilation should be minimal (ie, only the time required to deliver the first cycle of 30 chest compressions, or approximately 18 seconds; when 2 rescuers are present for resuscitation of the infant or child, the delay will be even shorter).
The New York Red Cross offers classes in CPR and First Aid.