Lowering the body temperature after someone’s heart has stopped beating may improve the odds of surviving with good brain function, a new study suggests.
In fact, patients whose body temperatures were lowered (therapeutic hypothermia) were nearly three times more likely to survive cardiac arrest, the study found. Those treated with the cold therapy were also 3.5 times more likely to have better mental function than those who didn’t receive the therapy, the researchers said.
“Our findings provide support for the idea that all unconscious post-arrest patients should receive aggressive care with therapeutic hypothermia,” said lead researcher Dr. David Gaieski, an associate professor of emergency medicine at the School of Medicine at Thomas Jefferson University in Philadelphia.
“Withholding (this treatment) does not make sense given these data and other data from other studies at many institutions around the world,” he said.
The report was published Nov. 16 online in the journal Circulation.
The body gets too little blood when the heart stops beating, or when blood flow is blocked by a blood clot or stroke, Gaieski said. In these situations, lowering the body’s temperature can help protect it, he explained.
Earlier studies have shown that the cold treatment can improve survival and brain function in people with “shockable” rhythms, such as ventricular fibrillation, the study said. Ventricular fibrillation is a condition where the lower chambers quiver, preventing the heart from pumping blood and causing cardiac arrest, the American Heart Association notes. In many of these cases the heart can be “shocked” into a normal rhythm, Gaieski said.
But there are cases of patients in cardiac arrest with “nonshockable” rhythms. This is when there is no electrical activity in the heart, or when there is electrical activity, the heart isn’t contracting and blood isn’t flowing, he explained. Currently, there aren’t a lot of hospitals using temperature-lowering therapy for patients who have a nonshockable rhythm, the researchers said.
For the study, Gaieski’s team looked at data from more than 500 patients whose hearts stopped beating between 2000 and 2013. All had nonshockable rhythms. Lowering the body’s temperature increased survival rates and brain function in these patients, the study said.
Dr. Robert Glatter, an emergency physician at Lenox Hill Hospital in New York City and a spokesman for the American College of Emergency Physicians, said, “This important trial demonstrates that cooling should be tried in all patients with cardiac arrest, regardless of the initial heart rhythm.”
Glatter noted that the actual number of patients who survive mentally intact remains low. But, he added, reducing the body temperature has been shown to have a positive effect on improving outcomes.
“There has been a slow adoption of this treatment from lack of understanding the benefits of this easily implemented therapy,” he said.
Glatter added that lowering body temperature doesn’t require special equipment. It can be accomplished using equipment already in every hospital, he said.