Push Hard, Push Fast: Inside the AHA`s New Guidelines for CPR and ECC

The long-awaited American Heart Association (AHA) 2005 Guidelines for CPR and Emergency Cardiovascular Care are out. They are the most evidence-based recommendations to date, and contain a number of items that should improve the way we provide emergency medical care. This overview touches on only the most clinically significant changes. A more in-depth description can be found in the AHA's Winter 2005-06 edition of Currents, and the full text of the guidelines appeared in Circulation (Vol. 112, Issue 24 Supplement; Dec. 13, 2005). They are also available at www.americanheart.org.

Most of the major changes in the 2005 guidelines involve improving CPR. As I've pointed out in the Medical Abstract Reviews column in this magazine, there has been a great deal of resuscitation research in the last few years looking at what interventions actually improve patient outcomes. It has become clear that improving CPR and reducing time to defibrillation are the two steps that can have the greatest impact on improving cardiac arrest survival rates.

Universal Changes
The new CPR guidelines are based on medical evidence that:

1. CPR improves survival after cardiac arrest
2. the quality of CPR matters; and
3. both lay rescuers and healthcare providers are not doing a good job at performing

1. The long delays in starting and interruptions in performing CPR;
2. Chest compressions that are often too slow and too shallow; and
3. Ventilations, especially with advanced airways, are too long and too forceful.

• Apply effective and rapid chest compressions ("Push hard and push fast").
• Use a compression-to-ventilation rate (for a single rescuer) of 30:2.
• Give ventilations over one second and until the chest just starts to rise.
• Give only a single defibrillation shock, followed by immediate CPR.

Lay Rescuer CPR
For the lay rescuer, the emphasis is on recognition and simplification. By improving their recognition of an emergency and simplifying the steps they take, laypersons should be better prepared to respond appropriately.

• The jaw thrust is eliminated and only the head tilt/chin lift will be taught.
• "Signs of circulation"-an attempt to improve upon the pulse check-has been discarded, and lay rescuers now start rescue breaths and chest compressions on all unresponsive victims who are not breathing normally.
• Rescue breathing without chest compressions will not be done.
• The choking victim is only asked one question: "Are you choking?" If there is no answer, the Heimlich maneuver is performed.

• A child is now up to the age of puberty-about 12-14-to better tailor treatment to the most likely cause of respiratory or cardiac arrest.
• Opening the airway is a higher priority than immobilizing the cervical spine, so if the airway cannot be opened with the jaw thrust maneuver, the head tilt maneuver can be used, and the head repositioned as needed for rescue breaths.
• Manually triggered oxygen-powered resuscitators have made a comeback, may be more effective than bag-mask ventilation and are now recommended for patients without an advanced airway.
• Once an advanced airway is in place, chest compressions are uninterrupted and ventilations are done at 8-10 per minute.
• Chest compressions are tiring, and rescuers often don't notice that they're pushing less forcefully and more slowly over time, so two rescuers should switch positions every two minutes.

• For ventricular fibrillation, a single defibrillation shock is called for, followed by an immediate two minutes of CPR. First shocks are highly effective, and patients who are successfully defibrillated still need an interval of CPR. It is better to perform immediate CPR after the first shock than delay circulation while attempting to analyze the rhythm and pulse.
• The first shock will be 300J monophasic and 120-200J biphasic.
• The International Liaison Committee on Resusci-tation's (ILCOR's) 2003 recommendation is reaffirmed: AEDs that can accurately diagnose pediatric rhythms can be used on children 1-8 years of age. Energy-attenuating pads are recommended, but if they are not available, a standard AED can be used.

• Chest compressions and defibrillation are the most important procedures to do first. An advanced airway may be delayed for several minutes.
• LMAs and Combitubes are safe and effective devices.
• There is greater emphasis on verification of endotracheal tube placement. CO2 detection is the primary means, and an esophageal detector device can be used if no CO2 is detected.
• For symptomatic bradycardia, the first atropine dose is 0.5 mg.
• High-dose epinephrine is no longer given to children.

Training
Lay rescuer and healthcare provider CPR and BLS training has well-recognized weaknesses and challenges:

• Bystanders only perform CPR in about a third of witnessed cardiac arrests. There is a great reluctance to perform mouth-to-mouth ventilations, and educating people about the low risk of infection has not been successful.
• The initial training and frequency of retraining is inadequate to acquire and maintain the number and complexity of included skills.

The 2003 ILCOR advisory statement, "Education in Resuscitation," points out that many studies have shown that traditional instructor/classroom-based training results in poor post-course performance and retention of skills. Alternative methods, such as video-assisted instruction and interactive computer simulation, need to be further evaluated and utilized.

Conclusion
The 2005 guidelines are an important step forward, and EMS systems should consider implementing many of the updates as soon as practical. Although the training materials have not yet been released, most of the updates will not require extensive efforts (e.g., ratio of compressions to ventilations, uninterrupted compressions after advanced airways), and can be done as part of a continuing quality-improvement process with updated protocols and focused training.

Angelo Salvucci, Jr., MD, FACEP, is an emergency physician and medical director for Santa Barbara County and Ventura County (CA) EMS Agencies, and chair of the California Commission on EMS.