Heart Patients May Be Saved By Hypothermia Treatment
Posted October 4, 2006 9:23 a.m. EDT
RALEIGH, N.C. — Hypothermia is low body temperature, and it can kill you. But the American Heart Association says that if it's used properly, induced hypothermia can save the lives of some heart patients.
Wake County is now one of only three places in the United States to use induced hypothermia for a select group of patients in cardiac arrest. From the ambulance ride to an emergency department, certain patients will spend 24 hours in mild hypothermia to give them a better chance of survival.
It's important to understand the difference between cardiac arrest and a heart attack. With a heart attack you may feel intense pain in the chest. You often remain conscious. Cardiac arrest is different.
The heart goes into ventricular fibrillation. It quivers uselessly and stops pumping blood. The victim is unresponsive. They stop breathing normally. Some patients don't fully respond to CPR and efforts to shock the heart back into rhythm.
For many of them, the American Heart Association recommends induced hypothermia therapy.
"Studies show, it does appear that people who receive this controlled cooling are more likely to leave the hospital neurologically intact", said Dr. Brent Myers with Wake County Emergency Medical Services.
Wake County EMS, WakeMed and Rex Healthcare will now use hypothermia for patients who meet certain criteria -- "a patient who's undergone cardiac arrest, that remains in a coma after they've been revived. And we have a pulse and good blood pressure", explained Dr. Robert Denton with Rex Healthcare Emergency Medicine.
The plan begins in the ambulance with special cooling wraps around the chest, head and legs and an intravenous cold saline solution. In WakeMed and Rex Emergency Departments, the Coolgard 3000 will cool the blood drawn through a catheter inside a large vein in the leg. "Their blood passes over, essentially, a cooling column and that takes heat out of the blood", said Dr. Paul Hinchey, an assistant medical director for Wake County EMS and a WakeMed Emergency Physician.
The body's normal temperature is 98.6 degrees Farenheit. The target temperature is 89.6 degrees Farenheit or 32 degrees celsiuis. As the body cools, the blood flow slows down. "So when the brain's least able to regulate its blood flow, we slow down the metabolic demand in the brain and that helps protect it", said Dr. Hinchey.
Wake County is one of the best places in the country to live if you suffer cardiac arrest. Studies have found that patients' chances of survival are three times the national average.
Hypothermia is not new in medical care. It's been used in some neurological and cardiac procedures. What is new is that it is becoming the standard of care for some patients in cardiac arrest.