HealthLine: Every Beat Of Your Heart

Cardiopulmonary Resuscitation is an emergency procedure used to restore blood  flow to the brain and the heart after the patient has stopped breathing and their heart has stopped beating.  CPR involves chest compressions at a rate of at least 100 per minute.  The rescuer will provide artificial breathing through either exhaling into the patient’s mouth or using a device that pushes air into the subject’s lungs.  A variation of CPR known as “hands-only” or “compression-only” CPR (COCPR) is gaining more attention as an option for lay persons, non-medical witnesses to cardiac arrest events.

In 2010, the Emergency Cardiovascular Care Committee (ECC) of the American Heart Association changed the initial sequence of steps from ABC (airway, breathing, chest compressions) to CAB (chest compressions, airway, breathing), except for newborns.  The compression depth for adults is at least 2 inches and the rate should be at least 100 per minute.  Studies concluded that stopping compressions in order to give ventilations to the patient are detrimental to their recovery as stopping compressions stops blood flow and drops the patient’s blood pressure.  In pregnant patients, when a woman is lying on her back the uterus will compress the vein that is responsible for returning blood flow to the heart.  It is therefore recommended that the uterus be pushed to the left or the patient be rolled 30 degrees while performing CPR.

Loss of heart activity is generally caused by an abnormal heart rhythm, most commonly; ventricular fibrillation, pulseless ventricular tachycardia, pulseless electrical activity (PEA), asystole known as “flat line,” or pulseless bradycardia, a slowing of the heart beat without a pulse.  CPR should be started before the rhythm is identified.  A defibrillator is a device that supplies an electrical current or “shock” to the heart intended to return it to a normal rhythm. CPR should continue while the defibrillator is being applied and charged.  In a study performed in Seattle, 84% of patients with an out-of-hospital arrest regained a pulse when defibrillated during ventricular fibrillation.

More than 300,000 cardiac arrests occur each year in the United States.  When CPR is used alone, there are few complete recoveries.  The function of CPR is to preserve the body until defibrillation and advanced cardiac life support are available. The survival rates for in-hospital cardiac arrests are generally consistent at 20-22% whereas bystander CPR provides a 4-6% survival rate.  Conversely, Return of Spontaneous Circulation (ROSC), where the heart beats on its own again, occurs in 48% of witnessed in-hospital cardiac arrests and 40% in bystander CPR.  This gives the patient a strong chance to survive in combination with rapid administration of defibrillation.

Several studies suggest that bystanders, lay persons or family members attempt CPR 14-45% of the time in cases of out-of-home cardiac arrest.  Since the median is 32%, this indicates that one-third of out-of-home arrests receive CPR.  Younger patients will have CPR attempted on them more frequently than older patients.  Bystanders in public will more commonly perform CPR than when the episode occurs in the patient’s home, and they are found by a family member.  It is believed that family members who find their loved one in arrest are in shock and not thinking clearly.

You can call your local fire department or hospital to find out the schedule for CPR training.  The life you save, may save you someday.

Dr. Ballard is a Board Certified Internist and Geriatrician with a special interest in Women’s Health.  She practices in Enumclaw, 360-825-1389.  Dr. Ballard’s comments are informational only and not to be construed as medical advice.  Consult your personal physician for any medical issues.