Some Cardiac Arrest Patients Get the Big Chill

It's taken about 7 years, but treating comatose survivors of cardiac arrest by cooling them down is finally hot.

In February 2002, reports from two independent, controlled studies showed dramatically improved neurologic and survival outcomes in patients resuscitated after cardiac arrest when their body temperatures were dropped to 32° C-34° C for 12–24 hours (N. Engl. J. Med. 2002; 346:549–56; 557–63). But despite an editorial that recommended immediate adoption of the treatment for cardiac-arrest survivors (N. Engl. J. Med. 2002;346:612–3), and further endorsement by the Advanced Life Support Task Force of the International Liaison Committee on Resuscitation in April 2003 (Resuscitation 2003;57:231–5), the treatment mostly languished in the United States for several years.

As recently as 2006, a survey of emergency medicine physicians, critical care physicians, and cardiologists found that 74% of respondents had never used therapeutic hypothermia (TH) in cardiac arrest patients (Crit. Care Med. 2006;34:1935–40).

Experts cite many reasons for the slow uptake, despite overwhelming evidence of the efficacy and safety as well as the relative simplicity and low cost of TH. A frequently cited explanation is the “legacy of nihilism” for treating CPR survivors, after decades of seeing most of these patients go on to a poor quality of life, said Dr. Clifton W. Callaway, an emergency medicine physician at the University of Pittsburgh. He also noted the small number of cardiac arrest survivors that any single physician usually sees, making him or her unfamiliar with these patients, and the relatively low level of commercialization of TH. The absence of a billing code and reimbursement for TH is another factor, said Dr. Bentley J. Bobrow, an emergency medicine physician at the Mayo Clinic in Phoenix. Another issue is that a diverse array of physicians, nurses, and technicians in different specialties must be on board in using TH as a cardiac arrest patient is transitioned from ambulance to emergency department to coronary care unit, said Dr. Robert W. Neumar, associate director of the center for resuscitative science at the University of Pennsylvania, Philadelphia.

But slowly, TH began being used by emergency medical services (EMS) personnel, emergency medicine physicians, cardiologists, neurologists, and nurses. By the end of 2008, it looked like TH finally had become the standard of care.

“There has been a major shift in the use of TH. We've seen a substantial increase in interest,” so that at the start of 2009 there is generally at least one large center routinely using TH for cardiac arrest patients in virtually every major U.S. metropolitan area, said cardiologist Dr. Mary Ann Peberdy, professor of medicine and emergency medicine at Virginia Commonwealth University in Richmond.

“The idea is treating cardiac arrest as a potential brain injury, not just a heart injury. It's a change so that it's not CPR, it's CCR: cardiocerebral resuscitation,” said Dr. Stephan A. Mayer, chief of the neurologic ICU at Columbia-Presbyterian Hospital, New York.

“Cooling for cardiac arrest has been a grassroots, bottom-up movement that has bubbled up where there have been local champions,” and now “it's absolutely at a tipping point,” Dr. Mayer said in an interview.

Although no group or registry keeps official tabs on how widely TH is used in America or elsewhere, here are a few examples of its spread:

▸ In December 2007, Dr. Bobrow launched a program to designate Arizona hospitals as cardiac arrest centers that required participating centers to use TH as well as other evidence-based facets of resuscitation, report their outcomes, and have percutaneous coronary intervention available around the clock. This is the first statewide program aimed at boosting use of TH, said Dr. Bobrow, who is also medical director for the Bureau of Emergency Medical Services of the Arizona Department of Health Services. By the end of 2008, Dr. Bobrow had enlisted 20 of the approximately 70 hospitals in Arizona into the program, and he hopes to involve another 20 centers in 2009. Before the program began, TH was available at only one Arizona hospital. The program also has EMS crews take patients to a participating cardiac arrest center while bypassing undesignated hospitals. By October 2008, about half of the more than six million residents of Arizona were in an area served by a cardiac arrest center. TH use increased from 2% of cardiac arrest patients before the program began to 34%, while survival to hospital discharge rose from 13% before to 22% with the program in place.

▸ Virginia Commonwealth University in Richmond was an early adopter of TH for resuscitated cardiac arrest patients, starting in late 2002, Dr. Peberdy said. But in February 2008, the program intensified. Working with the Richmond Ambulance Authority, EMS technicians began to infuse chilled saline into appropriate patients while in the ambulance to start TH as soon as possible. With cooling already begun, ambulance drivers began to take patients only to local centers with a protocol to continue TH once patients arrived, and at the time Virginia Commonwealth was the only Richmond hospital with a protocol. Ambulance crews also improved their resuscitation methods with an automated chest-compression device designed to boost blood flow, compared with conventional, manual chest compression.