In the 19 January 2005 issue of JAMA, the researchers show that, even in the hospital setting, chest compressions during CPR are often too slow, too shallow and too frequently interrupted, and ventilation rates are usually too high. A second study assessing out-of-hospital CPR by paramedics and nurse anesthetists in three European cities found even greater deviation from the guidelines, suggesting that the problem is endemic.
"CPR has been around for 50 years but until now we haven't had a precise, reliable way to assess how well it's being done," said study author Lance Becker, M.D., professor of emergency medicine and director of the Emergency Resuscitation Research Center at the University of Chicago. "Now we find that it's not being done very well."
The two JAMA studies "document a major problem in the treatment of cardiac arrest," notes an editorial that accompanies the papers, adding, "this conclusion is not surprising."
"You can't fix what you can't measure," Becker said. "Performing CPR was like driving a car without a speedometer, based more on feel than on feedback. Now, with a device that tells us how fast we are going, we think we can rein in the speeders and speed up those who fall behind."
The key to this study was an investigational monitor/defibrillator, developed by Laerdal Medical Corporation and Philips Medical Systems. The device records the rate and depth of chest compressions, the rate and volume of ventilations, and the presence or absence of a pulse. It also notes when no compressions are being performed and calculates total "no-flow" time, as well as the fraction of time during a cardiac arrest when there is no blood flow.