How the New AHA Guidelines for CPR and ECC May Help Improve Survival Rates

The 2010 AHA Guidelines for CPR and ECC (Emergency Cardiovascular Care) may well jumpstart survival rates from sudden unexpected Cardiac Arrest occurring Outside the Hospital (OHCA) from the dismal national average of 7(1)-8.5(2)   to 20% or more. The well-established A-B-C mantra (airway, breathing, circulation) that has been taught to the public for 50 years, has now been replaced with a new protocol for trained rescuers: C-A-B (compressions, airway, breathing)(3). So, trained rescuers should give 30 compressions at a rate of at least 100/minute, followed by two breaths.

When it comes to untrained rescuers, “hands-only CPR” is recommended for adult victims. This method, also known as “continuous chest compressions” (CCC) was pioneered by Gordon Ewy, MD, Lani Clark, Bentley Bobrow, MD, and colleagues at the University of Arizona. Since CCC was introduced in Arizona, survival rates have tripled (4.7% to 17.6%) among patients with the treatable heart rhythms of ventricular fibrillation [VF] or ventricular tachycardia [VT] whose arrests were witnessed.(4)

“I believe that the 2010 AHA Guidelines represent a significant advancement in our understanding of the great importance of high-quality chest compressions as the fundamental component of effective CPR for both lay and trained rescuers,” said Dr. Bobrow, medical director for emergency services for the state of Arizona, researcher at the Mayo Clinic in Scottsdale, and medical director of the Arizona Affiliate of the SCA Foundation National Survivor Network. “A community strategy of ‘hands-only CPR’ should increase bystander action and improve survival from cardiac arrest.”

Summary of Key Changes

Here are the key changes in the Guidelines:

Basic Life Support

• Start chest compressions right away for any unresponsive adult victim who is not breathing normally (rather than taking the time to “Look, listen and feel” or check for a pulse). Note: if someone is breathing abnormally, gasping, resuscitation efforts should begin immediately.
• Compress the chest at least two inches when helping adults.
• Compress the chest at least one-third of the anterior-posterior depth of the chest (about 1.5-two inches) when helping infants and children.
• For infants, use of manual defibrillator is preferred. However, AEDs, ideally those with a pediatric-dose attenuator, may now be used in infants if a manual defibrillator is not available.
• In patients with implantable cardioverter defibrillators (ICDs) or pacemakers, pad placement should not be delayed, though it is reasonable to avoid placement directly over the implanted device.
• Dispatchers should coach untrained rescuers to provide “hands-only” CPR.

 Advanced Life Support

• Quantitative waveform capnography is recommended for confirming and monitoring endotracheal tube placement and CPR quality. This is a new Class I recommendation for adult victims.
• There is an increased emphasis on:
  • Identifying weak links in the Chain of Survival that account for great variations in survival rates
  • Teamwork
• The following have been de-emphasized:
  • Drugs
  • Mechanical CPR devices (the jury is still out)
  • Pulse checks.
• The following are recommended:
  • Real-time monitoring and optimization of CPR
  • Use of adenosine and chronotropic agents for diagnosis and treatment of certain heart rhythms.
• The following are no longer recommended:
  • Atropine for routine treatment of pulseless electrical activity/asystole
  • Routine use of cricoid pressure during airway management
  • Routine calcium administration in pediatric patients.
• When sudden unexpected cardiac arrest occurs in a child or adolescent, healthcare providers should obtain a medical history. When resources allow, an autopsy should be performed and tissue should be preserved for genetic analysis to determine the presence of challelopathy (cardiac defects), which can cause fatal arrhythmias.

Post-Cardiac Arrest Care

• Post cardiac-arrest care is now considered the fifth link in the Chain of Survival. The AHA now recommends "comprehensive, structured, integrated multi-disciplinary systems of post cardiac arrest care.
• There is an increased emphasis on the use of mild therapeutic hypothermia for comatose adult victims to improve neurological recovery.

Rationale for Basic Life Support Changes

Why the CPR changes? Here’s the rationale:

• The C-A-B sequence allows chest compressions to be initiated sooner and ventilation is only slightly delayed. A growing body of research suggests that if high-quality chest compressions are started right away, the likelihood of survival increases dramatically.
• Victims usually have enough residual oxygen in their systems, at least for the first few minutes after cardiac arrest, to reduce the need for artificial respiration.
• Survival usually depends on what is done in the first five minutes after OHCA. Despite decades of public education, less than one-third of OHCA victims receive CPR from a bystander, and only 3% are treated with an automated external defibrillator (AED) used by bystander. A simplified public health message—“Push hard and fast in the middle of the chest”—may give more bystanders the confidence they need to get involved.

What hasn’t changed in the Guidelines is the emphasis on high-quality CPR (deep compressions with minimal interruptions that allow the chest to recoil between compressions) and rapid defibrillation. Survival rates are highest among victims of all ages whose arrests are witnessed and who are experiencing ventricular fibrillation (VF) or ventricular tachycardia (VT). For these patients, chest compressions and use of AEDs is most critical.