Based upon the 2010 American Heart Association Guidelines for CPR and ECC, the sequence for CPR has been changed from A-B-C (Airway-Breathing-Compressions) to C-A-B (Compressions-Airway-Breathing). Changing the sequence from A-B-C to C-A-B allows all rescuers to begin chest compressions right away. Research shows that rescuers who started CPR with opening the airway took 30 critical seconds longer to begin chest compressions than rescuers who began CPR with chest compressions. View the video/link above for more information.
2010 AHA Guidelines for CPR and ECC