The American Heart Association's long-awaited new guidelines for CPR reflect what the resuscitation community has learned in recent years: that fast, high-quality compressions, started quickly and sustained, are among the most vital components to helping a sudden cardiac arrest victim survive.
In its new 2010 Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, just published in the AHA journal Circulation, the organization reorders the traditional A-B-C of care to put the C, for circulation, first. Now, responder or lay person, you call a C-A-B.
"For more than 40 years, CPR training has emphasized the ABCs of CPR, which instructed people to open a victim's airway by tilting their head back, pinching the nose and breathing into the victim's mouth, and only then giving chest compressions," guidelines coauthor Michael Sayre, MD, chair of the AHA's Emergency Cardiovascular Care Committee, said of the change. "This approach was causing significant delays in starting chest compressions, which are essential for keeping oxygen-rich blood circulating through the body. Changing the sequence from A-B-C to C-A-B for adults and children allows all rescuers to begin chest compressions right away."
Previously, the guidelines instructed rescuers to open the airway, then look, listen and feel for normal breathing, and to deliver two rescue breaths before starting compressions on an unresponsive patient. Now, conversely, they should start compressing immediately on those who are unresponsive and not breathing normally.
The reason: In the initial moments after an arrest-precipitated collapse, victims still have oxygen in their lungs and bloodstream, and the faster compressions begin, the faster that oxygen can be moved along to the brain and heart. With airway as the top priority, rescuers may instead delay to deliver breaths, retrieve a mouth barrier or collect and prepare ventilation equipment. Rescuers who pause to open the airway, research suggests, can take up to 30 seconds longer to start pushing the chest.
With that in mind, professional rescuers should now perform a quick check for abnormal or no breathing when they check responsiveness. Providers should spend no more than 10 seconds checking for a pulse before starting CPR, then use a defibrillator when it's available.
For trained rescuers, the previously recommended ratio of 30 compressions to two breaths has not changed; the compressions just come first. As before, rescue breaths should be given in approximately one second. Trained lay rescuers should continue this cycle until a rescue professional takes over. Once an advanced airway is in place, professional rescuers can revert to continuous compressions and no longer cycle with ventilations.
Other important changes and aspects:
- The recommended compression rate is now at least 100 a minute, instead of approximately 100 a minute. The Bee Gees song "Stayin' Alive" is still a good pacing aid.
- The recommended compression depth is now at least 2 inches (5 cm) in adults, instead of 1½ to 2 inches. For infants and children, compress at least one third of the anterior-posterior diameter of the chest, or approximately 1½ inches (4 cm) in infants and 2 inches (5 cm) in children.
- Allow full chest recoil after each compression. Avoid leaning on the chest between compressions.
- Minimize interruptions to compressions.
- Avoid excessive ventilation.
- Use of cricoid pressure during ventilations is generally not recommended.
SCA survival rates are highest among those who experience witnessed arrests and initial rhythms of ventricular fibrillation or pulseless ventricular tachycardia. The C-A-B change is also expected to benefit the critical element of bystander CPR. Instead of being asked to open the airway and provide breaths, lay rescuers now need only start pushing.