In a major change, the American Heart Association (AHA) now encourages bystanders who witness an adult's sudden cardiac arrest outside a hospital to activate emergency medical services, then provide chest compressions "hard and fast in the middle of the victim's chest, with minimal interruptions." Previously, the AHA recommended alternating 30 chest compressions with two quick rescue breaths, although giving only chest compressions was an acceptable option for those unwilling or unable to provide rescue breathing.
The change was triggered by research showing that survival to hospital discharge in adult out-of-hospital cardiac arrest victims was equivalent in those receiving chest compressions without rescue breaths and those
receiving conventional cardiopulmonary resuscitation (CPR) consisting of chest compressions plus rescue breaths. Experts believe that the simpler approach will encourage more and better-quality bystander CPR. Conventional CPR is still an option for appropriately trained rescuers who choose to use it in these circumstances and is still required for unwitnessed cardiac arrest, cardiac arrest in children, and cardiac arrest presumed to be noncardiac in origin.
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