The new C-A-B (Compressions, Airway, and Breathing) sequence, before anything else, shows rescuers to perform chest presses. But after four decades, the AHA implement such an extreme change when there is a lot of buzz surrounding the A-B-C to C-A-B update. This is because it requires anyone who learned CPR previously to get re-educated, but the AHA thinks that it is just too much that it cannot balance the advantages to the disadvantages.