The ABCs of CPR--again.

Survival rates for cardiac arrests that occur in hospitals and outside them continue to be low (17% and 6%, respectively), and fewer than one-third of patients who have an out-of-hospital cardiac arrest receive cardiopulmonary resuscitation (CPR). Consequently, a number of changes were made to the 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. The changes were intended to simplify CPR in order to increase its use and effectiveness by both clinicians and nonprofessionals. This article summarizes the primary changes to the recommendations, including a universal 30-to-2 compression-to-ventilation ratio for all lone rescuers, the need for compressions of sufficient depth and number, and the replacement of the three-shock model of initial defibrillation with one that recommends a single shock, now seen as an adequate precursor to CPR.