The research tested 104 adults untrained in CPR and 83 fire-fighters, trained in the procedure. The findings showed that most of the untrained people simply do not apply enough force, said Leslie Geddes of Purdue University, one of the authors of the study.

The success rate for CPR ranges from five percent to ten percent, depending on how quickly it is administered after a person's heart stops. "This is important because every minute lost in applying CPR results in a ten percent decrease in successful resuscitation," Geddes said. "Time is the enemy. After ten minutes, very few are resuscitated. The American Heart Association recommends pushing with enough force to compress the chest 1.5 to two inches, which requires 100 to 125 pounds of force.”

The research represents the first time such measurements have been recorded to quantify just how hard people push in a simulated CPR test. The people in the study were asked to push on a bathroom scale as though they were performing CPR, and their force was recorded by the scale. The findings showed that 60 percent of the CPR-trained rescue personnel pushed with more than 125 pounds, whereas more than 60 percent of those not trained in CPR failed to push with more than 125 pounds of force.

Pushing with more than 125 pounds increases the potential for rib fractures. Nevertheless, the chances of survival increase enormously. New guidelines from the American Hearth Association recommend that rescuers performing CPR should "push harder and faster," Geddes said. "As a result of this recommendation, it's likely that the resuscitation rate will increase, but it's equally likely that the fracture rate will increase."

MEDICA.de; Source: Cardiovascular Engineering / Springer