Menus Subscribe Search

Follow us


Cardiac Arrest’s Heartwarming Hope: Hypothermia

• September 08, 2008 • 10:00 PM

Dramatically cooling patients after cardiac arrest improves survival, recovery.

The woman was sitting in a friend’s car laughing at a joke when suddenly she slumped over, unresponsive. The panicked driver had the presence of mind to speed 15 blocks to the nearest hospital, the University of Chicago Medical Center, where doctors determined she had suffered a potentially lethal cardiac arrhythmia and worked to get her heart beating normally.

Then they put her on ice. The sedated woman’s body temperature was rapidly lowered, putting her in a state of mild hypothermia, and kept there.

“She should not have done well,” said Dr. David Beiser, one of the emergency-room physicians who treated the woman, “but we cooled her, and six days later she woke up.” The woman has since returned to work.

Roughly 90 percent of the 300,000 people who suffer cardiac arrest in the U.S. each year die, but a growing body of research shows that cooling a patient’s body to around 32-34 degrees Celsius (89-93 degrees Fahrenheit) after restarting the heart significantly improves survival.

Doctors may use ice packs, cooling blankets, an intravenous drip of chilled saline solution or special catheters with refrigerated tips to lower the patient’s core temperature and keep it there for up to 24 hours.

“Hypothermia represents one of the most important advances in cardiac care since the development of defibrillators 50 years ago,” said Dr. Benjamin Abella, an assistant professor of emergency medicine at the University of Pennsylvania. “If it was being aggressively implemented in hospitals, we would probably have thousands more survivors of cardiac arrest every year.”

Although cardiac arrest is “one of the most lethal conditions in medicine,” Abella said most doctors still are not using it on a routine basis. He co-authored a 2005 study showing that many wrongly believed there was insufficient evidence to adopt the procedure.

Cardiac arrest is not the same thing as a heart attack. In a myocardial infarction, a blocked coronary artery may cause chest pain and shortness of breath, but the condition can often be treated with clot-dissolving drugs, angioplasty or stents.

Cardiac arrest, where the heart loses its rhythm or stops beating altogether, may follow a heart attack or strike without warning. A sudden loss of consciousness results as blood flow to the brain stops, and if the heart is not restarted quickly, death follows.

A 2003 report in the American Heart Association journal Circulation found that prospective randomized trials in Europe and Australia had shown inducing mild hypothermia in comatose survivors of out-of-hospital cardiac arrest led to higher survival rates and fewer neurological complications.

In the European study, patients were kept chilled for 24 hours before being allowed to rewarm naturally. The study of 273 patients found 55 percent of the hypothermia group patients were living independently six months later, compared with 39 percent in a control group of patients who did not receive hypothermia treatment. And at six months, only 41 percent of the hypothermia group had died, while 55 percent of the un-chilled group had.

Doctors in the Australian study, conducted at four hospitals in Melbourne, used cold packs to cool patients. Their lowered temperatures were maintained for 12 hours after admission, and active rewarming started at 18 hours. This study of 67 patients found that 49 percent of its hypothermia group survived, as compared with only 42 percent of the unchilled control group.

The Circulation article’s authors endorsed the October 2002 recommendations of the International Liaison Committee on Resuscitation, which said, “Unconscious adult patients with spontaneous circulation after out-of-hospital cardiac arrest should be cooled to 32 degrees Celsius to 34 degrees Celsius for 12 to 24 hours when the initial rhythm was ventricular fibrillation (VF).”

Beiser, an assistant professor of emergency medicine at Chicago, is conducting animal studies to try to understand how hypothermia protects patients. The research could yield lifesaving — and potentially lucrative — results. “We’re looking at pharmaceuticals that mimic hypothermia,” he said.

Most people understand the danger to the oxygen-starved brain when the heart stops pumping blood, but many other secondary injuries also occur when circulation stops. “We’re beginning to understand how the secondary injury occurs and how to limit it,” Beiser said. “When you restart the heart and blood goes back to previously blood-starved tissue, you create a lot of oxidants, which can damage the tissue or transmit signals (that) can trigger cell death and inflammation.”

Patients revived from cardiac arrest sometimes suffer something called total body inflammation, which may stop capillaries from working and obstruct blood flow to vital organs, he said.

Hypothermia modulates this secondary injury, increasing certain oxidants and decreasing others, Beiser said, but exactly how is not well understood. For a long time, scientists thought it had to do with reduced energy needs. “The initial hypothesis with cooling is that we’re decreasing the metabolic rate of the body,” Beiser said.

“What we’re actually finding is it’s turning up the transcription of certain genes while turning down the transcription of other genes,” he said, referring to the genetic activity involved in the production of new proteins within cells.

One might expect emergency physicians would rush to embrace the use of therapeutic hypothermia, given the robust research in support of its use, but that hasn’t been the case. In the February 2005 issue of the journal Resuscitation, Abella, Chicago’s Terry Vanden Hoek and others reported that a survey of 265 physicians had found 87 percent said they were not using the technique.

“Among reasons cited for non-use, 49 percent felt that there were not enough data, 32 percent mentioned lack of incorporation of hypothermia into advanced cardiovascular life support (ACLS) protocols, and 28 percent felt that cooling methods were technically too difficult or too slow,” the report said.

Another reason may be that many doctors believe that there is little that can be done for cardiac arrests.

“There’s a culture of despair and a feeling of futility in these cases,” said Beiser, who adds that he makes sure to let his ER staff know about successful outcomes from hypothermia treatment to instill a sense of optimism.

“This culture of hope really helps get hypothermia off the ground in an institution.”

Sign up for our free e-newsletter.

Are you on Facebook? Click here to become our fan.

Add our news to your site.

Michael Haederle
Michael Haederle lives in New Mexico. He has written for the Los Angeles Times, People Magazine, Tricycle: The Buddhist Review and many other publications. He has also taught at Syracuse University's S.I. Newhouse School of Public Communications and is a Zen lay monk.

More From Michael Haederle

A weekly roundup of the best of Pacific Standard and PSmag.com, delivered straight to your inbox.

Recent Posts

October 17 • 4:00 PM

What All Military Families Need to Know About High-Cost Lenders

Lessons from over a year on the beat.


October 17 • 2:00 PM

The Majority of Languages Do Not Have Gendered Pronouns

A world without “he.” Or “she.”


October 17 • 11:01 AM

How to Water a Farm in Sandy Ground

Physicists investigate how to grow food more efficiently in fine-grained soil.


October 17 • 10:00 AM

Can Science Fiction Spur Science Innovation?

Without proper funding, the answer might not even matter.


October 17 • 8:00 AM

Seattle, the Incredible Shrinking City

Seattle is leading the way in the micro-housing movement as an affordable alternative to high-cost city living.


October 17 • 6:00 AM

‘Voodoo Death’ and How the Mind Harms the Body

Can an intense belief that you’re about to die actually kill you? Researchers are learning more about “voodoo death” and how it isn’t limited to superstitious, foreign cultures.


October 17 • 4:00 AM

That Arts Degree Is Paying Off

A survey of people who have earned degrees in the arts find they are doing relatively well, although their education didn’t provide much guidance on managing a career.


October 16 • 4:00 PM

How (Some) Economists Are Like Doomsday Cult Members

Cognitive dissonance and clinging to paradigms even in the face of accumulated anomalous facts.


October 16 • 2:00 PM

The Latest—and Most Mysterious—Player in the Nasty Battle Over Net Neutrality

As the FCC considers how to regulate Internet providers, the telecom industry’s stealth campaign for hearts and minds encompasses everything from art installations to LOLcats.


October 16 • 12:00 PM

How Many Ads Is Too Many Ads?

The conundrum of online video advertising.


October 16 • 11:00 AM

Unlocking Consciousness

A study of vegetative patients closes in on the nature of consciousness.


October 16 • 10:00 AM

The False Promises of Higher Education

Danielle Henderson spent six years and $60,000 on college and beyond. The effects of that education? Not as advertised.


October 16 • 8:00 AM

Faster Justice, Closer to Home: The Power of Community Courts

Community courts across the country are fighting judicial backlog and lowering re-arrest rates.


October 16 • 6:00 AM

Killing Your Husband to Save Yourself

Without proper legal instruments, women with abusive partners are often forced to make a difficult choice: kill or be killed.


October 16 • 4:00 AM

Personality Traits Linked to Specific Diseases

New research finds neurotic people are more likely to suffer a serious health problem.


October 16 • 2:00 AM

Comparing Apples to the Big Apple: Yes, Washington, D.C., Is More Expensive Than New York City

Why shouldn’t distant locales tied to jobs in the urban core count in a housing expenditure study?


October 15 • 4:00 PM

Why Asian American Parents Are the Least Likely to Spank Their Kids

Highly educated, middle-class parents are less likely to use corporal punishment to discipline their children than less-educated, working-class, and poor parents.


October 15 • 2:00 PM

The Federal Government’s New Doctor Payments Website Is Worthy of a Recall

Charles Ornstein takes a test drive using the federal government’s new website for drug and device payments and finds it virtually unusable.


October 15 • 12:00 PM

How Cosmetic Companies Get Away With Pseudoscience

Anti-aging creams make absurd claims that they repair DNA damage or use stem-cell treatments. When cosmetics companies and dermatologists partner to maximize profits, who is responsible for protecting the consumer?


October 15 • 10:00 AM

What Big Data Can Tell Us About the Things We Eat

Pizza might be the only thing that can bring men and women together.


October 15 • 9:04 AM

‘Looking’ at Art in the Smartphone Age

Technology is a great way to activate gallery space, but it shouldn’t take it over.


October 15 • 8:00 AM

A Brief History of High Heels

How what was once standard footwear for 16th-century Persian horsemen became “fashion’s most provocative accessory.”


October 15 • 7:22 AM

Advice for Emergency Alert Systems: Don’t Cry Wolf

A survey finds college students don’t always take alerts seriously.


October 15 • 6:00 AM

The Battle Over High School Animal Dissection

Is the biology class tradition a useful rite of passage or a schoolroom relic?


October 15 • 4:00 AM

Green Surroundings Linked to Higher Student Test Scores

New research on Massachusetts schoolchildren finds a tangible benefit to regular exposure to nature.


Follow us


How to Water a Farm in Sandy Ground

Physicists investigate how to grow food more efficiently in fine-grained soil.

Unlocking Consciousness

A study of vegetative patients closes in on the nature of consciousness.

Advice for Emergency Alert Systems: Don’t Cry Wolf

A survey finds college students don't always take alerts seriously.

Brain’s Reward Center Does More Than Manage Rewards

Nucleus accumbens tracks many different connections in the world, a new rat study suggests.

A City’s Fingerprints Lie in Its Streets and Alleyways

Researchers propose another way to analyze the character and evolution of cities.

The Big One

One company, Amazon, controls 67 percent of the e-book market in the United States—down from 90 percent five years ago. September/October 2014 new-big-one-5

Copyright © 2014 by Pacific Standard and The Miller-McCune Center for Research, Media, and Public Policy. All Rights Reserved.