A growing body of research is proving that dropping body temperature by several degrees following cardiac arrest can protect nervous system function in those critical moments when blood flow to the brain is dangerously interrupted. Hypothermic treatment presents an important intervention for people who suffer cardiac arrest outside the hospital and have approximately a 2 to 8 percent survival rate. The treatment is especially beneficial for younger patient populations who don’t have the same chronic disease as their older cohorts, said Suhail Allaqaband, M.D., FSCAI, clinical adjunct professor of cardiology and associate program director of interventional cardiology fellowship for Aurora Health Care in Milwaukee, WI.
“When you look at national survival rates, the statistics are very dismal,” Dr. Allaqaband added. “We believe that, especially in younger patients, if you treat aggressively with hypothermia early on, it can significantly improve survival.”
Every year an estimated 359,400 Americans experience cardiac arrest outside of the hospital and enter a pulseless state requiring assistance by emergency medical personnel, according to a 2013 report by the American Heart Association. Hypothermia treatment, carried out within hours of cardiac arrest, brings the body temperature down several degrees from the norm of 98.6 degrees Fahrenheit by way of cold saline fluid IV, ice-packing, ice water baths and swaddling with cold blankets, or a combination of these. Interventional hypothermia treatment can also be combined with drugs that reduce shivering and muscle tension.
This study looked at 179 patients who suffered cardiac arrest and were treated with hypothermia to see who had a better chance of survival. According to results of the study, survival rates of people under the age of 65 spiked exponentially to 43 percent. Survival was also improved for those who were older, by 29 percent.
“Hypothermia treatment improves survival significantly because it has been shown to decrease brain damage due to low oxygen supply,” explained Anushree Agarwal, M.D., lead author of the study and a clinical cardiology fellow working with Dr. Allaqaband.
According to the data, younger patients were more likely to experience cardiac arrest due to drug abuse instead of cardiovascular disease. Substance abuse was found to be the cause of cardiac arrest in 38 percent of those under 65 years of age. The younger cohort also had a better chance, 71 percent, of being released from the hospital following treatment.
About 36 percent of elderly patients who were treated with hypothermia were able to go home without maintaining significant injury. Those who underwent emergency cardiovascular catheterization were also found to have better odds of survival.
“Patients who were treated with hypothermia had a better chance of being released from the hospital without suffering from extensive neurological damage or slipping into a vegetative state,” said Dr. Allaqaband.
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