CPR research: Increasing survival after cardiac arrest
Research in emergency medicine, including how to improve survival rates, has been a keystone of the career of Roger D. White, M.D. His work and dedication have helped save thousands of lives.
Not all superheroes wear capes. Roger D. White, M.D., an anesthesiologist who favors button-down shirts and ties, has saved countless lives through groundbreaking work in cardiac resuscitation at Mayo Clinic in Rochester, Minn. His discoveries helped pave the way for the placement of defibrillators in airports and other public places, better CPR practices and education, and faster emergency response times. Mayo Clinic made headlines recently when Dr. White directed a helicopter flight crew that successfully performed CPR on a man with no pulse for 96 minutes. The patient, 54-year-old Howard Snitzer, recovered completely.
"I feel awesome. I'm ready to take on the world," Snitzer says. After his record-setting cardiac arrest, he was transported to Saint Marys Hospital, one of Mayo Clinic's hospitals in Rochester, and later treated for underlying heart disease. "I guess you could say I'm pretty lucky. But I know it goes beyond that."
A plain-spoken man, Dr. White says simply: "It's a gratifying thing to bring people back to life, and send them home again."
Sudden cardiac death is one of the six leading causes of death in the U.S. Like Snitzer, many cardiac arrest patients have no history of heart disease yet suddenly experience ventricular fibrillation — a rapid, erratic heartbeat that causes the heart's pumping chambers (ventricles) to quiver uselessly instead of pumping blood. As a result, blood supply to vital organs, including the brain, is cut off. Prompt CPR and shocks to the heart (defibrillation) can boost survival rates.
"If you do it right," Dr. White says, "you have a good chance of patient survival."
A pillar in emergency resuscitation
Doing it right is possible in large part because of Dr. White. When he joined Mayo Clinic 40 years ago, emergency medical services (EMS) were in their infancy. Back then, the chances of surviving cardiac arrest when it occurred outside a hospital were slim. But many of Dr. White's published findings have been incorporated into the American Heart Association (AHA) resuscitation guidelines, helping boost today's survival rates.
"We have used his experience and research to shape the science of resuscitation," says Mary Fran Hazinksi of Vanderbilt University, a registered nurse who serves on emergency care guideline panels. "His influence is not just a drop in a pond. It's a major torrent that goes beyond the patients he touches."
"Dr. White is a pillar in the field of critical resuscitation," says Daniel G. Hankins, M.D., an emergency medicine physician at Mayo Clinic in Rochester, Minn. "He was into EMS before EMS was cool."
Dr. White trained in internal medicine and anesthesiology and was interested in resuscitation from the very beginning. "I was fascinated by ambulances," he recalls. "Yet their minimal equipment limited what they could do. I was convinced that victims of cardiac arrest were dying needlessly. I felt that we could do much more to improve survival."
On his first day at Mayo Clinic in 1970, Dr. White contacted the local ambulance service to volunteer his time training emergency medical technicians. Three years later, he became the service's medical director. That position, which he still holds, has been an ideal springboard for his innovative research.
Improvements for those first on the scene
Early on, Dr. White noticed that Rochester police officers, who had long provided first aid in response to EMS calls, frequently arrived at the scene before the ambulance. If the police had defibrillators, Dr. White reasoned, they could shock a patient's heart before paramedics arrived, improving the chances of survival.
"It was kind of weird to consider police officers operating a defibrillator. It had never been done before," Dr. White says. "But it worked."
Before Rochester police carried defibrillators, only 35.7 percent of patients with bystander-witnessed, out-of-hospital cardiac arrest from ventricular fibrillation survived without brain damage. Within five years, that increased to 43.4 percent. In a 1996 study, Dr. White found that rapid defibrillation was the major factor, and that reducing the time between the emergency call and the first shock by even one minute increased the likelihood of restoring the patient's circulation.
Firefighters and sheriff's officers were later added to the defibrillator program. By 2008, the overall Rochester cardiac arrest survival rate was up to 49.5 percent — a huge improvement, and one that compares favorably to elsewhere in the U.S., where survival ranges from just 7.7 to 39.9 percent.
"If you're in a shockable heart rhythm in Rochester and somebody sees you collapse, we'll get you back home about 50 percent of the time," Dr. White says.
An evidence-based approach
Mayo Clinic's evidence-based approach to cardiac resuscitation requires meticulous attention to detail. For Dr. White, one challenge was tracking EMS response times down to the second. Bruce W. Goodman, the Mayo One helicopter paramedic at Snitzer's resuscitation, has worked with Dr. White for 15 years. He recalls having to synchronize his defibrillator to the Universal Time at the start of his shifts.
"Dr. White is very knowledgeable and very supportive. At the same time, he is very demanding," Goodman says with a laugh. "It's all about learning what we can do better."
"It was very onerous," Dr. White agrees. "But when we published our research, we knew we were publishing honest numbers. I am still obsessed with that level of detail. I insist that the data we collect, analyze and report be precise."
All that attention to detail helps give Mayo Clinic research wide credibility. As one of the authors of the AHA resuscitation guidelines, Dr. White helps set standards for:
Paramedics arrive at cardiac arrest scenes armed with that knowledge, along with fastidious training. "Dr. White teaches us to use critical thinking skills as well as technology," says Daniel J. Anger, who manages Mayo Clinic's medical helicopter paramedics. "He reminds us to look at the patient, not just the monitors."
Doing it right: A case study
In Snitzer's case, that knowledge and training came together in spectacular fashion. When Snitzer collapsed in rural Minnesota one winter night, a bystander and a trained first responder quickly started CPR. Additional first responders arrived within minutes and administered defibrillation and continued CPR. Thirty-four minutes after the original 911 call, Goodman arrived on the scene with the Mayo One medical helicopter.
That's when yet another piece of Dr. White's research came into play. Mayo Clinic's defibrillators are equipped with capnography, a technology that measures how much blood is flowing through the lungs and therefore to other organs. Although capnography has long been used in operating rooms to guide anesthesiologists, it isn't widely used outside the hospital, even by emergency responders. But back in the 1980s, Dr. White realized the potential benefit of this technology for cardiac resuscitation: If capnography was used during CPR and showed that sufficient oxygenated blood was reaching the patient's brain despite having no pulse, rescuers might be motivated to continue their resuscitation efforts. So Mayo Clinic began equipping its defibrillators with the capnography technology, including the Mayo One defibrillator that Goodman used on Snitzer.
Throughout Snitzer's long cardiac arrest, capnography indicated that sufficient oxygenated blood was reaching his brain — thanks to 22 first responders who lined up, bucket brigade style, and took turns doing forceful chest compressions. His heart rhythm, although in ventricular fibrillation, was benefitting from the shocks of the defibrillator. So Dr. White, speaking on the telephone from Rochester, instructed Goodman to keep going.
"With that combination of a treatable rhythm and good oxygenated blood flow, we couldn't just stop," Dr. White says.
Snitzer marvels at the sequence of events. "There are so many things that fell exactly into place — the capnography, Mayo One, the people so committed to doing CPR," he says. "Mayo arguably is the only place this could have happened."
Directing resuscitation from afar
Dr. White's telephone presence that evening was no quirk of scheduling. He's notified of every cardiac arrest 911 call, even when he's out of the country. "The most unusual was a cardiac arrest I directed from a hotel in Zagreb," he says.
He also routinely gives his cellphone number to first responders so that they can call him when needed. "That can be at 2 in the morning or 9 at night," Goodman says. "It doesn't matter. Dr. White is that dedicated to patient care and to his research."
That accessibility has made Dr. White a popular mentor at Mayo Clinic. "He is the epitome of the Mayo collaborative model of patient care," says Dawit T. Haile, M.D., a Mayo Clinic anesthesiologist in Rochester. "He is approachable at work, off work, or if you are calling him at odd hours of the night."
Dr. White is quick to credit his Mayo Clinic colleagues for making his work possible. "I am surrounded by tremendous support here," he says.
His latest focus is therapeutic cooling, which involves lowering the body temperature to 91.4 degrees Fahrenheit for 24 hours after cardiac arrest to promote neurological recovery. "After patients are resuscitated and in the hospital, you take the next step to protect the brain, so they have still another opportunity to go home," Dr. White explains. "Underneath it all is the science of resuscitation. It's what intrigues me and propels me to keep finding better ways to do these things."
— November 2011