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Medical Community Embraces Induced Hypothermia for Cardiac Patients

MILKWAUKEE, Wis. — As he raced across town to the hospital, Adrian Roberson knew something bad had happened to his wife, Darrice, but he was unprepared for what he would find in the emergency room.

Darrice Roberson, a 33-year-old mother of three, had suffered a cardiac arrest last year and had been brought back to life by an electric shock.

Now doctors at Froedtert Hospital were putting her on ice, literally covering her body with ice packs and sending frigid saline solution into her veins.

They gave her a paralyzing drug to prevent her from shivering as they plunged her body temperature to about 90 degrees.

“I touched her arm and leg,” Adrian Roberson said. “She was icy cold. It didn’t seem right, someone being that frigid.”

Over the next 24 hours, Darrice Roberson would be kept in a hypothermic state to preserve her brain cells.

When doctors began rewarming her, she would emerge as one of the lucky ones.

Last July, Darrice Roberson was one of a handful of cardiac arrest patients from the area to benefit from a new treatment known as hypothermia therapy.

Not many more patients have received the treatment since then, though doctors say it is inexpensive, relatively easy to perform, has only a small risk of causing serious complications and could benefit hundreds of patients around the state.

Few hospitals in southeastern Wisconsin or around the country regularly perform the therapy, though it can improve survival and preserve brain function by about one-third over conventional treatment.

Indeed, since 2003, the American Heart Association has recommended the use of hypothermia in cardiac arrest cases caused by an arrhythmia known as ventricular fibrillation. The organization also says hypothermia might be beneficial for other types of cardiac arrest.

“It’s the only therapy that I know can improve long-term survival,” said Terry Vanden Hoek, an associate professor of emergency medicine at the University of Chicago Medical Center, and a member of the group that developed the heart association’s recommendation.

It also improves the ability of patients to function, allowing some to go home or go back to work, he said.

Uncertainty cited

But not everyone is fully convinced.

“I think there still is a great deal of uncertainty,” said Lee Biblo, vice chairman of medicine at the Medical College of Wisconsin in Wauwatosa. “It’s a neat little thing to do. I think the data weakly supports a benefit.”

Biblo — who practices at Froedtert in Wauwatosa, where the treatment will become standard this month — said the therapy is supported by two small studies.

He said hypothermia is not without risk. Potential side effects include infections such as pneumonia, increased risk of blood clots and the possibility of developing an arrhythmia.

(In the two clinical trials so far, there was no increase in complications or adverse events caused by the hypothermia.)

Biblo acknowledged that he would recommend the therapy for his patients and even for a family member, but said he is not sure that it will have a huge impact in the field of medicine.

Less than 80 miles away, however, doctors are so convinced of the therapy’s value that soon paramedics will be performing it in the field. For more than a year, the therapy has been a standard treatment at the University of Wisconsin Hospital and Clinics in Madison.

Starting March 1, cardiac arrest patients will get the therapy before they arrive at the hospital, said Darren Bean, an assistant professor of emergency medicine at UW.

Paramedics will sedate the patients, administer a paralytic drug and infuse frigid saline into their veins, starting the cooling therapy in the field. As many as 100 people a year will receive the therapy, he said.

“It’s not rocket science,” Bean said.

More important, he said, the therapy can mean the difference between patients surviving in a persistent vegetative state or surviving with most of their brain function intact.

Milwaukee County paramedics eventually also might start cooling cardiac arrest patients in the field, but not until all the hospitals in the county are committed to continuing the therapy once patients reach the hospital, said Ronald Pirrallo, director of medical services for Milwaukee County Emergency Medical Services.

“My hope is that this year, multiple hospitals will make a commitment,” said Pirrallo, a professor of emergency medicine with the Medical College.

In Milwaukee County, about 200 people a year who suffer a cardiac arrest outside the hospital and are revived would be candidates for the therapy, said Tom Aufderheide, a professor of emergency medicine at the Medical College who practices at Froedtert.

“There should be no hospital that can’t do this,” Aufderheide said.

But at the moment it’s a matter of geography as to whether a cardiac arrest patient will receive the therapy.

Paramedics generally take those patients to the nearest hospital, and it is a matter of chance — with the odds being less than 1 in 5 — that they will get the therapy at a Milwaukee-area hospital.

Indeed, the therapy itself seems to have been in a deep freeze for the past few years, an example of how long it can take for the mainstream medical community to warm up to a new idea. Although some hospitals have experimented with it, the therapy only now is crossing the threshold from novel to accepted practice.

“I don’t think there is any excuse for it, but it takes 15 years for (a new therapy) to really penetrate in medicine,” said Guy Clifton, a hypothermia researcher and professor and chairman of the department of neurosurgery at the University of Texas Health Science Center at Houston.

Clinical trials

For decades, there have been hints that cold brains did better than warm ones in cardiac arrest cases.

Since the 1950s, hypothermia has been used in the operating room to protect the brain in patients undergoing open-heart surgery.

At the same time, there have been countless anecdotal reports of miraculous outcomes after kids fell through the ice and were submerged for long periods or adults who arrived at the hospital cold after their hearts stopped while outside in frigid temperatures.

Eventually those incidents led to studies in which hypothermia was deliberately induced, including two clinical trials published in the New England Journal of Medicine in 2002.

In one study involving 77 cardiac arrest patients, 49% of those treated with hypothermia survived and had a good neurological outcome, compared with 26% of those who did not get hypothermia therapy.

In the other study, which involved 273 cardiac arrest patients, 55% of those who got hypothermia therapy had a favorable neurological outcome, compared with 39% of those who did not get the therapy.

Nationally, 50,000 people could benefit from the therapy, but only about 1 in 4 hospitals offer it, said Benjamin Abella, an assistant professor of emergency medicine at the University of Pennsylvania.

“Right now there is a therapy that can save thousands of lives a year that isn’t being implemented by hospitals,” Abella said. “It’s unfortunate that implementation has been so slow.”

In 2006, Abella and other physicians published research showing that 74% of U.S. doctors working in emergency medicine, cardiology and critical care medicine had not used hypothermia.

Commonly cited reasons were “not enough data,” “too technically difficult” and “have not considered it.”

In his study, Abella compared the lag in lack of acceptance of hypothermia therapy to other treatments such as the use of beta-blocker drugs after a heart attack.

Doctors and nurses who have seen the therapy in action say it has led to some remarkable recoveries.

In at least two cardiac arrest patients at Aurora St. Luke’s Medical Center in the past year, the initial outlook was grim, said Karin Schmeling, a clinical nurse specialist at the hospital. However, after being put into hypothermia, the patients did much better than expected, she said.

The success of the therapy, she said, has led to a saying among doctors and nurses who have used the therapy:

“You’re not dead until you’re warm and dead.”

It might be another four years before the matter is settled.

That’s when a clinical trial of up to 1,200 cardiac arrest patients in the Seattle area is scheduled to be completed. The trial will test the use of hypothermia therapy started in the field by paramedics.

‘Quality of survival’

Clara Ellison remembers sitting in her living room with a funny feeling and tightening in her chest.

When emergency medical personnel arrived a few minutes later, she was on the floor and her nephew was performing CPR.

“We shocked her three times,” said Dave Howard, director of ambulance services at Moundview Memorial Hospital in Friendship, where Ellison lives. “We lost a pulse and shocked her three more times.”

In the ambulance, she had to be shocked again before being taken by Med Flight to UW Hospital in Madison.

After cooling her to about 90 degrees for 24 hours, doctors began rewarming her.

“When you start the rewarming process, you just hold your breath,” said UW’s Bean. “You just don’t know. In her case, she just woke up.”

Ellison, 64, doesn’t remember much about the ordeal, but she says she is convinced that hypothermia therapy is one of the reasons why she is alive and doing well.

“I feel great,” she said.

UW Hospital has performed hypothermia therapy on about 20 cardiac arrest patients since about a year ago, Bean said.

Although there still is some mystery about how it works, hypothermia slows down metabolism in the brain and calms the squall of damaging brain chemicals that bursts in when the blood supply is restored after a long interruption. The ideal temperature range — 89.6 degrees to 93.2 degrees — has to be maintained for 24 hours.

Bean said he believes that the sooner hypothermia is started, the better. He noted that survival rates for cardiac arrest are dismal. Even among those who reach the hospital, up to 70% die.

“We have to rethink this disease and be very aggressive about it,” he said.

And the therapy is not just about improving mortality rates, he said.

“It’s about quality of survival,” he said. “We don’t want people surviving in persistent vegetative states. The worse thing would be having people survive to be in a nursing home for 25 years.”

A new life

Adrian Roberson is watching his wife as she lies unconscious in the ICU at Froedtert Hospital. The couple’s three children, ages 13, 9 and 2 months, are at home with Darrice’s mother.

Electrodes are attached to her head to monitor brain wave activity.

Suddenly a buzzer goes off, alerting a nurse that her body temperature has dropped below 91 degrees. The nurse takes some of the ice packs off her body.

A few hours later, nurses start rewarming her.

Her eyes open. She looks at her husband.

She still has the breathing tube in her mouth, so he gives her a piece of paper and a pencil.

“Why am I here?” she asks.

The breathing tube is removed.

She says, “Hi.”

Darrice Roberson remains in the hospital for another 10 days, and a defibrillator is implanted in her chest.

Today her brain function is normal, but there is no way of knowing if it’s because of the hypothermia.

“I feel like it never happened,” she says.

A month or so after going into cardiac arrest, she becomes pregnant. The baby, a boy, is due in April.


* Froedtert Hospital in Wauwatosa has used the therapy on occasion, so far on four cardiac arrest patients. By the end of this month, it will begin using hypothermia therapy on all eligible cardiac arrest patients coming into the hospital, an estimated 33 patients a year, said Tom Aufderheide, a professor of emergency medicine at the Medical College of Wisconsin who practices at Froedtert.

* Waukesha Memorial and Oconomowoc Memorial hospitals do not perform hypothermia therapy, said David Cullinane, a cardiologist and medical director of ProHealth Care’s Heart Center at Oconomowoc Memorial Hospital.

“It’s under review,” he said. “We are looking at developing a protocol.”

* Community Memorial Hospital in Menomonee Falls does not perform the treatment, according to a spokeswoman.

* On rare occasions it has been done at Columbia St. Mary’s Hospitals, said Richard Shimp, chairman of emergency medicine at Columbia St. Mary’s Hospital Milwaukee. It’s been used once at the Milwaukee hospital and twice at the Mequon hospital, he said. The hospitals are waiting for more data on the therapy, he said.

“It’s kind of new,” he said. “There is no obvious benefit.”

* The therapy is not performed at four Wheaton Franciscan Healthcare centers: Wisconsin Heart Hospital in Wauwatosa; St. Francis in Milwaukee; Elmbrook in Elm Grove; and All Saints in Racine, though All Saints is planning to start a program in the next year, said a Wheaton Franciscan spokeswoman.

Another Wheaton Franciscan facility, St. Joseph hospital in Milwaukee, has used it in six to eight cases, said Mark Mitchell, medical director of the emergency department at the hospital.

“We’ve had a couple remarkable recoveries,” Mitchell said.

* Neither Aurora Sinai Medical Center nor Aurora’s West Allis Memorial Hospital performs hypothermia, but Sinai is planning to begin offering it by the end of the year, said an Aurora spokesman.

Aurora St. Luke’s Medical Center has had a hypothermia program for about a year but does not perform the therapy in all cases, said Karin Schmeling, a clinical nurse specialist at the hospital.

“We have a protocol in place,” Schemling said. “Whether it is used is physician-driven. The managing physician has to buy into it.”

In the past year, the hospital performed hypothermia therapy on about 15 cardiac arrest patients and could have performed the therapy on about the same number but did not, she said.

She said some doctors remain skeptical about the science supporting the therapy.