to treat cardiac arrest Doctors cool the body
To treat cardiac arrest, doctors cool the bodyUpdated 12/11/2006 12:44 AM ETBy Robert Davis, USA TODAY
When his heart stopped in the middle of his workday, Dean Cowles fell clinically dead in one of the best places in the world to suffer sudden cardiac arrest.
The 57-year-old engineer collapsed on July 18 in King County just outside Seattle, a community that leads the USA in saving lives because of a commitment to cutting-edge emergency medicine.
He was surrounded by co-workers who knew what to do when his body seized and he gasped for air; for years they have taken classes in cardiopulmonary resuscitation.
His heart quivered in an electrical short-circuit in a building in which Dean and his friends make defibrillators, the device he would need — fast — if he were to be revived.
A by-the-book rescue restarted Cowles' heart. But when he did not wake up after his heart was restarted, his doctors say, he needed a treatment that most Americans don't get — induced hypothermia — in which doctors lowered his body temperature to about 91 degrees.
As Cowles' body struggled to recover from a cascade of biological problems that can follow sudden clinical death, his heartbeat was strong but his brain was competing with every other organ for oxygen.
Hypothermia therapy has for years been used in the operating room when doctors want to slowly reduce a patient's need for oxygenated blood during heart and other surgeries. While researchers do not fully understand why, studies have shown that cooling allows the body to get by with less oxygen by decreasing the metabolic demand.
When King County paramedics rolled Cowles into the emergency department at Evergreen Hospital Medical Center two miles from his office, he had a strong pulse but was still unconscious. The hospital team applied pads to his legs and chest and used a machine to lower his body temperature.
"It's pretty much become the standard of care," says Cowles' cardiologist, Mark Vossler. "Cooling slows down the metabolism and decreases the brain's demand for blood flow. That's the theory."
Cooling the body gives the brain a break while other organs compete for oxygen in a crisis, doctors say. Hypothermia protects the brain cells from damage, a common problem following sudden death.
Cowles doesn't remember his hypothermic "coma," which lasted about 24 hours.
Most doctors continue to give hypothermia the cold shoulder, despite studies detailing the benefits in the New England Journal of Medicine in 2002, international recommendations in 2005 urging the treatment, and inclusion in the most recent American Heart Association's lifesaving guidelines for cardiac arrest care.
He says doctors must include cooling so that if a patient who arrives at the hospital with a heartbeat after suffering a cardiac arrest goes on to die, "it's not because of something we neglected to do for the patient."
"Sometimes nature just holds all the cards," says Callaway. "But you don't want for it to be that you left cards on the table."
How cooling helps
As Cowles' co-workers at Medtronic's Emergency Response Systems office performed CPR, they each saw for the first time what a freshly dead person looks like. After his body tensed up like he was having a seizure and he made gasping and groaning noises, all of his muscles went flaccid. He was lifeless. "He started to go gray," says Cowles' boss, Steve Firman.
After CPR and two shocks from the automated external defibrillator (AED) kept on the kitchen wall at the office, "Dean's pulse came back," Firman says. "He started breathing on his own. It was like a field of pink washed over his face."
Many of the cardiac arrest victims who are revived across the USA with CPR and rapid defibrillation make it to the hospital with a pulse, but they do not walk out. Brain damage can be severe.
Cowles collapsed in a city that leads the nation in its attempts to save more lives — by training more residents in CPR, deploying more AEDs and measuring the performance of its paramedics.
Nearly half of the people like Cowles survive and walk out of Seattle-area hospitals. On average across the nation, experts say, fewer than 10% are that lucky.
The best test of a clinical treatment is often to randomly put patients with the same medical condition into two groups, one that gets the therapy and one that does not, and then measure the results to determine if those who got the treatment fared better.
But some doctors say hypothermia treatment is so clearly beneficial that it is now unethical to deny one group a procedure known to be effective.
"I could no longer participate in a study that randomized somebody to not get cooled," says Mary Ann Peberdy, an associate professor of medicine at Virginia Commonwealth University in Richmond. In her hospital, VCU Medical Center, staffers began cooling their cardiac arrest survivors more than two years ago and doubled survival rates. "I've made my survival twice as good. I couldn't go back."
Nurses from the intensive care unit tell Peberdy "we've never seen people wake up and walk out of here like we are seeing now," she says. "We're really doing something good. It gives you chills."
Raleigh, N.C., is not waiting.
In Wake County, and across the nation, each segment of the emergency medical system tends to operate in its own narrowly focused trench. Paramedics are the first to treat cardiac arrest patients with advanced life support. The patient is then handed off to emergency room physicians. If they're still alive after an hour or more, the patient is then moved to an intensive care unit, where that team takes over."Hypothermia is a therapy that, for the patient to benefit from it, the whole system has to be integrated," says Callaway, an associate professor in emergency medicine at the University of Pittsburgh.
In Wake County, it was the ambulance service that led the way. "Typically, the EMS field waits years for hospital-based or lab-based treatment protocols to trickle down to pre-hospital care," says Jeffrey Hammerstein, Wake County EMS spokesman. "Our docs did the research and pushed this program up through the hospitals. With a lot of cooperation and work, they came on board."
Now, Wake paramedics begin the hypothermia treatment in the field by administering a sedative that prevents shivering, applying ice packs and infusing chilled intravenous fluids. The paramedics then bypass three hospitals with cardiac arrest survivors to take those patients to two hospitals, WakeMed Raleigh and Rex health care, that provide cooling therapy.
Callaway says that by bypassing the closest hospitals to go to more specialized heart centers, Wake County EMS may be taking the next big step in cardiac-arrest care. Just as some trauma centers specialize in critical care, some hospitals might concentrate on treating cardiac arrest survivors.
"In some ways, cardiac arrest patients are sicker than trauma patients," he says. "Right now we take them to the closest hospital, and that facility might see one or two of those patients a month. It's not an equitable matching of resources and patient need."
Some people think that itís holding on that makes one strong; sometimes itís letting go.