When it comes to CPR, timing is everything
UMKC researchers are helping to re-write the book for first responders
Matthew Gratton, M.D., a long-time emergency physician and seasoned combat physician, knows all too well the critical importance of applying the right medical treatment at the right time. When it comes to sudden cardiac arrest, for example, the timing and the treatment can literally mean the difference between life and death. That’s why Gratton, chair of the UMKC Department of Emergency Medicine, and his research colleagues are encouraging emergency response personnel to re-evaluate their protocols for treating cardiac arrest patients.
“We used to routinely stop compressions to ventilate the patient or to insert an IV or to administer multiple shocks,” Gratton said. “But, over the last several years, more and more of the scientific literature began to suggest that perhaps that was misguided.”
Most notably, Gratton looked at the research of Gordon Ewy, M.D., of the Sarver Heart Center at the University of Arizona. Ewy is a leading proponent of continuous chest compression and a long-time researcher into the pathophysiology of the arrested heart. His research has shown that interruptions in chest compressions significantly decrease coronary and cerebral blood flow.
Others were taking note of this as well, including Alexander Garza, M.D., who is a former medical director of the Kansas City Emergency Medical Services (EMS) System and former faculty member at the School of Medicine. (Garza was recently appointed assistant U.S. secretary of health affairs and chief medical officer in the Department of Homeland Security.)
In 2005, based on Ewy’s research and numerous other corroborating studies, Garza felt the science was compelling enough to put a new protocol for responding to sudden cardiac arrest into practice in Kansas City. In determining the protocol for implementation, Garza collaborated with Gratton and Joseph Salomone, M.D., associate professor of emergency medicine at UMKC and the medical director of the Kansas City EMS System.
“Our approach was to get rescuers to concentrate most on giving more rapid, deep and uninterrupted compressions when working with sudden cardiac arrest,” Gratton said.
They then studied the results from changes in CPR methods as implemented by the Kansas City EMS System in 2006 and 2007. The Kansas City EMS System prioritized the use of at least 50 chest compressions before administering two breaths. The change also meant that EMS personnel focused more on compressions and less on intubating patients, starting IVs and delivering medications. Current American Heart Association recommendations call for a 30/2 ratio of compression to ventilation.
When comparing the previous three years to the year following the change in protocol, Gratton and his colleagues found that there was a marked increase in overall sudden cardiac arrest survival rates (7.5 percent to 13.9 percent). They also found that patients in a shockable rhythm (ventricular fibrillation) who were witnessed to arrest and who were resuscitated with the new protocol improved their hospital discharge rate from 22.4 percent to 43.9 percent. Their findings were published earlier this year in Circulation, the scientific journal of the American Heart Association.
“It really comes down to timing and the physiological changes that are taking place when a person is in cardiac arrest. As what’s going on in a cardiac event changes, what needs to be done changes, too,” Gratton said. “When the patient’s physiology is basically normal, except for heart rhythm, in the first four to five minutes, defibrillation is appropriate. After that, a shock may be ineffective, due to a lack of oxygen in the blood, and actually cause the patient to flatline.”
Gratton and his colleagues are in the process of a follow-up study in which they have further increased the number of uninterrupted compressions from 50 to 200.
“We are still compiling numbers, but the preliminary data looks very promising,” Gratton said. “Emergency medical services around the country are beginning to change their protocols to reflect the recommendations for increased chest compressions. This has the potential to save thousands of lives every year.”
Posted: August 2, 2010