The 2015 American Heart Association guidelines update for pediatric basic life support (BLS) emphasizes significant changes from previous versions, particularly regarding the sequence of CPR and the importance of ventilation during pediatric cardiac arrest. It recommends using the C-A-B (compressions-airway-breathing) sequence and highlights that pediatric cardiac arrest often has asphyxial causes, making ventilation critical. The update also stresses the need for high-quality CPR, including proper compression depth and rate, and provides new recommendations based on a systematic review of relevant literature.