Researchers Say Overzealous CPR May Cost Lives

Well-meaning paramedics may be losing heart patients by trying to resuscitate them too vigorously, researchers said Monday.

The researchers found that some ambulance crews giving cardiopulmonary resuscitation, or CPR, were giving more than the American Heart Assn.’s recommendation of 12 to 15 breaths per minute.

This may mean they are doing little good, the researchers report in today’s issue of the journal Circulation.

“The overall survival rate in the United States from cardiac arrest is about 5%,” said Dr. Tom Aufderheide, a professor of emergency medicine at the Medical College of Wisconsin in Milwaukee, who led the study. “Excessive ventilation may be contributing to that poor outcome.”

His team studied 13 cardiac arrest victims. For the first seven patients, the average maximum ventilation rate was 37 breaths a minute. Even after retraining, the paramedics gave 22 breaths a minute to the next six patients.

One solution might be to use a system that flashes a light every five seconds to let a rescuer know when to deliver another breath of oxygen, Aufderheide said.

During CPR, the chest is compressed, raising pressure and forcing blood out of the heart and into the rest of the body. When the pressure is released, the chest expands, creating a slight vacuum inside.

The body needs this vacuum for blood in the veins to return to the heart most efficiently, said the American Heart Assn., which publishes Circulation. Without the vacuum, not as much blood returns to the heart.

“The decreased return of blood to the heart reduces the blood going out of the heart, and that may decrease the effectiveness of CPR,” Aufderheide said.