October 9, 2007

Hospital treatments buy heart attack victims more time

Laronda Vassers got into her neighbor’s car at the 69th Street Red Line stop. Moments later, the neighbor noticed Vassers was quieter than normal. Too quiet, in fact. She was unresponsive, and within 10 minutes the car had squealed up to the UC Hospitals E.R. entrance.

It was another 20 minutes before a nurse and security guard wheeled her inside and doctors were able to restart her failed heart. Many teams would have given up on Vassers, and, in fact, some doctors that night wanted to do so. After all, the survival rate for people down that long is nearly nothing.

Instead, the team decided to cool Vassers’ body down to near 90 degrees for 24 hours and then slowly warm her back up. The practice, called therapeutic hypothermia, was recently endorsed by the American Heart Association thanks in part to the work of doctors at the U of C’s Emergency Resuscitation Center (ERC).

The body is sometimes cooled with either external ice packs or a catheter with a heat exchanger threaded into the patient’s blood vessels. The preferred method at the UC Hospitals is an IV drip of chilled saline, according to Dr. Dave Beiser, an emergency medical physician who is part of the ERC.

Twenty-four hours ticked by, and Vassers was re-warmed but remained in a coma. Forty-eight hours later her family was still in agony. After 96 hours doctors were hoping for the best but expecting the worst. Then, on the sixth day, she awoke.

Vassers, a medical secretary, was shocked to hear what had happened. “I just started crying, because that’s a miracle. Nobody’s down that long and survives,” she said.

“She was dead for half an hour, and she walked out. That’s what makes it worth it for us,” Beiser said.

Although the practice is AHA–endorsed, many hospitals still don’t cool cardiac arrest patients.

Multidisciplinary effort

The Emergency Resuscitation Center is a consortium of research scientists, clinical doctors and nurses, and educators at the U of C and Argonne National Laboratory. The Center’s mission, as described by director Terry Vanden Hoek, is to figure out how best to normalize the body after a cardiac arrest or massive blood loss.

The ERC’s work began not in a crowded emergency room, but with a few cells in a petri dish. Researchers cut off the oxygen and nutrients to the cells to mimic a cardiac arrest. To their surprise, the cells actually exploded once oxygen and nutrients were restored, dying faster than if they had simply been allowed to starve.

So just restoring oxygen and blood flow isn’t the best thing doctors can do for a cardiac arrest patient, researchers found. “You need hibernation, or antioxidants, or something to prepare your body. Sort of like starting a nuclear reactor, there’s a logical order for re-booting,” said Beiser.

Other researchers are trying various methods to improve survival in lab animals. One of the key developments from this research has been a refinement in CPR technique. Researchers discovered that chest compressions are far more important for survival than mouth-to-mouth ventilation. In fact, too much breathing puts pressure on the chest, restricting the blood flow that is CPR’s goal.

Education is key

“Dr. Cart, Dr. Cart, Room D401,” called Dana Edelson, the ERC’s director of clinical research. A septic 71-year old African-American female with cirrhosis and renal failure had just coded.

Fortunately, the bright-eyed medical residents hearing the cry were seated calmly around a table on the Hospital’s seventh floor rather than in the E.R. They were attending the Center’s weekly Code Review, a session in which the residents responsible for saving lives gather to discuss their cases, step-by-step. The goal: to improve the quality of resuscitations performed at the hospital.

Lavanya Kondapalli, a second-year internal medicine resident, calls the reviews very useful. “There are 15 people who show up to the codes, it’s very chaotic, and you need to know how to schedule your time to save patient’s life. This helps,” she said.

And education doesn’t stop at the hospital’s doors. Ellen Demertsidis, the Center’s community training coordinator, works with high-rise offices, museums, and other public places to install defibrillators, develop emergency plans, and train staff members in CPR. She estimates the ERC’s community work has saved 10 or 12 lives, including that of an ex-police officer who collapsed at the Daley Center in May.

The future

The Center is currently working on several projects. Some researchers are looking into the genomics of hypothermia. If they can determine which bodily processes are affected by hypothermia, doctors hope they can develop a cocktail of drugs to mimic those symptoms without the danger of lowering core body temperature. Until then, they’re using animal models to determine how fast, how deeply, and for how long humans should be cooled.

The ERC is also teaming up with the University of Michigan and the Department of Defense to improve therapies for soldiers on the battlefield who suffer massive blood loss.

Ultimately, the doctors are just hoping to be able to help more people like Laronda Vassers. Beiser put it simply: “Patients other people wrote off, we will bring them back.”