Freezing the Heart to Save the Life

And a lot can. In the early stages of cooling, Barco’s heart wasn’t pumping strongly enough. The nurses kept her on blood-pressure medications and reduced her saline, because when the heart is not pumping properly, fluid can collect in the lungs. If her body temperature had slipped below 86°, her heart could have immediately failed.

Becker and Abella are now working to address at least some of the practical resistance to hypothermia by designing studies to determine the most effective ways to cool. If the parameters are more clear-cut, the protocol more established, they believe it will be easier for hospitals to adopt. Yet they may have just dug themselves a deeper hole. Their latest research, which indicates that patients may be better off if doctors begin cooling even before they restart the heart, will require more precision and an even greater trust in the treatment. How long will a doctor or EMT really let someone lie there with her heart stopped while he gets the ice ready?

AN IV SLUSHEE

On May 20, 1999, 29-year-old Anna Bagenholm was skiing with friends near Narvik, Norway, one of the most northerly towns in the world. A little after 6 p.m., on a path down a waterfall gully, she crashed and fell headfirst into a river. Her body wedged between some rocks and overlying ice; fortunately, she found an air pocket so she could breathe. Her friends found her almost fully immersed underwater. But they couldn’t get her out.

Ten minutes passed as Bagenholm struggled in the icy water. Twenty. Thirty. After 40 minutes, her body went limp—either she had drowned or the cold had stopped her heart. When the rescue team arrived at 7:40, they cut a hole in the ice and took her body out. Her temperature was 57.9°. They inserted a breathing tube and began continuous CPR. Her heart wouldn’t restart, but pumping would at least get some oxygen to her organs.

An hour-long helicopter ride brought Bagenholm to the Tromsø University Hospital, where she was put on a heart-lung machine that breathed and pumped blood for her as she rewarmed. At 10 p.m. her heart started beating regularly on its own. By morning, her body was back up to normal temperature. Doctors sedated her for another three days and then slowly took her off the drugs. Eventually, she opened her eyes. She was alive and responsive, her brain virtually undamaged despite more than an hour without oxygen. After four months of rehabilitation, she went back to work.

Becker read Bagenholm’s story in the medical journal the Lancet in January 2000, while he was deep into his own hypothermia research. He was stunned at how long she had survived without oxygen, but the variable was clear: Bagenholm was cold before her heart restarted. “It was one of the stories that exemplifies that there is great potential for [hypothermia] if we could figure out how to use it in an optimal way,” Becker says. He and Abella now think “optimal” means “sooner.”

In a study they published in 2007, the pair showed that mice in cardiac arrest were more likely to survive if the experimenters waited to resuscitate them until after cooling had started. It was a provocative finding, because it suggested that the damage caused by a few extra minutes of oxygen deprivation is mitigated by getting a jump start on the cooling. The faster doctors can cool a patient, the fewer cells will die as they’re reperfused.