Richmond Ambulance Authority nearly doubled prehospital ROSC rate because of the ARCTIC program

A sudden cardiac arrest victim. Image: Calbear22

The Richmond Ambulance Authority is consistently on the cutting edge of prehospital medicine.  Partnering with the Virginia Commonwealth University Medical Center on a groundbreaking treatment of sudden cardiac arrest has nearly doubled the rate of return of spontaneous circulation (ROSC).  The Advanced Resuscitation Cooling Therapeutics and Intensive Care Center, or ARCTIC, program combines early medication administration, mechanical CPR and the initiation of therapeutic hypothermia in the prehospital setting with continued intensive care at VCU.

Dr. Joseph P. Ornato, M.D., RAA's operational medical director and chair of the Department of Emergency Medicine at the VCU School of Medicine, announced the impact of the ARCTIC program on cardiac arrest survivability during the Resuscitation Science Symposium at the American Heart Association Meeting, November 14-15, 2009 in Orlando, Florida.  Looking at the 1,598 cases of adult, out-of-hospital cardiac arrest that occurred in the City of Richmond between 2001 and 2008 enabled the team to evaluate the impact of the evolution of resuscitation and post-resuscitation protocols.  The rate of ROSC nearly doubled, from 25 percent in 2001 following RAA's standard treatment guidelines, to 46 percent in 2008.  Not only did ARCTIC dramatically improve the rate of prehospital ROSC, it also nearly doubled the rate of survival to hospital discharge.  Only 9.7 percent of cardiac arrest patients survived long enough to be discharged in 2003 but 17.9 percent achieved that milestone by the end of 2008.

A second review of 181 consecutive, out-of-hospital cardiac arrest patients resuscitated in the field and then treated at VCU between 2001 and 2009 showed how dramatically therapeutic hypothermia improved patient outcomes.  Only 19 percent of those patients survived to hospital discharge between 2001 and 2003 when treated with standard post-resuscitation care.  Thirty-eight percent of the patients between 2004 and 2007 survived when treated with simple cooling techniques.  After the introduction of the ARCTIC program, 49 percent of the patients between 2008 and 2009 survived to hospital discharge.  If a patient's cardiac arrest was due to ventricular fibrillation, s/he had a 72 percent chance of survival if treated in the ARCTIC program.

To understand why therapeutic hypothermia is so important to the survival of cardiac arrest, it is important to understand what happens to the body after the heart stops and after it starts again.  Within 10 to 20 seconds after the heart stops beating, the brain and organs are deprived of oxygen.  It was thought that permanent brain injury would occur after four to six minutes of hypoxia but recent research has shown that to be incorrect.  Brain cells function abnormally soon after the heart stops but it is now understood that brain damage occurs after ROSC.  The cells try to use the oxygen but because they are damaged, they convert the oxygen into free radicals, which in turn kill the cells.  That is why nationwide only 6-7% of cardiac arrest victims survive to hospital discharge if they are treated using the current standard practices.  Initiating hypothermia improves the survival rate because the cold slows the brain's metabolism so it cannot produce free radicals.  “What we now know is that we have to protect the brain and vital organs during resuscitation and after the heart is restarted and this has led to a totally new strategy for how we treat cardiac arrest patients,” said Dr. Ornato.

RAA paramedics are the first in the nation to initiate hypothermia in the field.  In the case of atraumatic ventricular fibrillation or pulseless ventricular tachycardia, and witnessed atraumatic arrest, adult patients receive normal saline chilled to at least 40 degrees Fahrenheit instead of the usual room temperature fluid.  Otherwise, standard RAA cardiac arrest protocols are followed.  An orogastric temperature probe is inserted to monitor the core body temperature.  RAA uses the Zoll AutoPulse, a mechanical CPR device that compresses the entire chest and therefore dramatically improves blood flow and oxygenation.  Adding the therapeutic hypothermia to the early administration of medications, defibrillation, Zoll AutoPulse CPR and airway management is only the first step in the ARCTIC program, though.  "One of the novel things about VCU’s ARCTIC program is that we have been able to seamlessly incorporate the care of the cardiac arrest patient from the time they arrest in their home to the time they return home with good neurologic survival,” said Mary Ann Peberdy, M.D., professor of Medicine and Emergency Medicine in the Division of Cardiology at the VCU School of Medicine.

Any patient that has been treated using the ARCTIC protocol must be transported to the VCU Medical Center.  Upon arrival at the emergency room, the patient is transferred to a team of physicians and nurses specially trained in post-resuscitation care.  To continue the cooling process, a plastic coil called the Alsius Endovascular Cooling System is inserted into the femoral vein and rests in the inferior vena cava just below the right atrium.  The patient is treated in the Coronary Care Unit where his/her temperature is dropped to 93 degrees Fahrenheit for at least 24 hours.  Rewarming is carefully controlled by a computer at a rate of 0.5 degrees Celsius per hour.  Until ARCTIC, cooling was achieved using simple external techniques such as cooling blankets or ice packs.  While those patients had a better chance of recovery than patients who did not receive any sort of therapeutic hypothermia, there was little control over the core temperature.  Large swings in body temperature can reinitiate metabolism and cause free radical production.  One of the ways ARCTIC is so unique is the precise control over the patient's temperature. 

Sudden cardiac arrest used to claim many more lives.  Occasionally a new treatment emerges that truly makes a difference.  First, it was CPR, and then it was defibrillation that dramatically improved the survivability of cardiac arrest. The newest great leap forward is therapeutic hypothermia and the ARCTIC program.  The Richmond Ambulance Authority and VCU Medical Center have revolutionized the treatment of the cardiac arrest patient.  What was once considered a death sentence, cardiac arrest is now realistically survivable and nearly 50 percent of patients could return home thanks to the ARCTIC program.

Sources:

1. Dr. Joseph P. Ornato, MD, Richmond Ambulance Authority operational medical director and chair of the Department of Emergency Medicine at the VCU School of Medicine.
2. VCU News Center, "Resuscitation and survival rates from out-of-hospital cardiac arrest nearly double with comprehensive treatment protocol."  Virginia Commonwealth University.

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