The Big Chill: Improving Life After Heart Attack
A new technology used to cool down patients after cardiac arrest to decrease and/or eliminate brain damage is making a difference in the Rochester area. A team of neurologists, cardiologists, critical care specialists, and emergency medicine clinicians at the University of Rochester Medical Center's Strong Memorial Hospital have been seeing dramatic patient outcomes as a result of a new water circulating system that lowers a patient's inner core temperature in hopes of stemming any brain damage resulting from loss of blood and oxygen flow to the brain.
Strong Memorial was the first hospital in upstate New York to acquire the Medivance Arctic Sun non-invasive cooling system technology last August, and remains upstate's only hospital to routinely incorporate the practice into its patient response protocol. Currently, Medivance is the sole manufacturer of this non-invasive cooling technology, eventhough several invasive endovascular methods are currently being evaluated in clinical trials.
According to Scott Burgin, M.D., assistant professor of Neurology, while for years clinicians have observed that decreasing the body's inner temperature appeared to be beneficial to those who suddenly were deprived of oxygen for short periods of time, it was only three years ago that research studies published in the New England Journal of Medicine outlined definitive benefits.
"The brain can only tolerate a brief period of deoxygenation before the neurons begin to whither and die," Burgin said. "By bringing down the inner body's core temperature to about 92 degrees Fahrenheit, we are able to slow down metabolism, inflammation and the release of harmful neurotransmitters, in effect giving patients a chance at a full and meaningful recovery after cardiac arrest.".
According to the American Heart Association, there were more than 1.1 million heart attacks or myocardial infarctions (MI) last year in the United States, killing about 40 percent of its victims in any given year. Of the survivors, chances of a significant recovery depend on how quickly the heart can be started, and what treatments can be put into place to decrease any negative effects from the oxygen-starved brain.
The Medivance Arctic Sun uses pads that adhere to the skin to circulate cooled water. The pads are applied with a gel to the thighs, trunk and back, and a computer monitors the patient's temperature and automatically cools or warms the circulating water as needed. A person's core temperature can commonly be decreased to the correct zone within two hours. After 24 hours, the body is gradually rewarmed.
Before this system was available, some clinicians would try a variety of methods to decrease body temperature, such as placing ice packs or cooling blankets in and around the patient. However, these methods were inefficient and difficult to routinely integrate into patient care.
Stringent criteria are in place to ensure the technology is being used on appropriate patients, and patient selection begins as soon as the patient enters the emergency department. Clinicians have up to six hours after the cardiac arrest to begin the cooling process, but "the sooner the better," said Frederick S. Ling, M.D., director of the Cardiac Catheterization Laboratory, who worked with Burgin to bring the system to the Medical Center.
"We have the ability to restart and fix the heart after cardiac arrest, but until cooling therapy, there was little we could do to prevent stroke or even brain death as a result of the arrest," said Ling. "With this technology, we can give our patient's the best hope of a meaningful recovery, not just of body, but also of mind.".