According to background information in the article, survival from cardiac arrest remains low despite the introduction of CPR over 50 years ago. The delivery of CPR, with correctly performed chest compressions and ventilations, exerts a significant survival benefit. Conversely, interruptions in CPR or failure to provide compressions during cardiac arrest have been noted to have a negative impact on survival in animal studies. Consensus guidelines clearly define how CPR is to be performed, but the parameters of CPR in actual practice are not routinely measured, nor has the quality been known. Recent studies have challenged the notion that CPR is uniformly performed according to established international guidelines.
This study examined in-hospital cardiac arrests at the University of Chicago Hospitals from December 11, 2002 until April 5, 2004. Using a monitor/defibrillator with novel additional sensing capabilities, the researchers recorded parameters of CPR quality including chest compression rate, compression depth, ventilation rate and the fraction of arrest time without chest compressions (no-flow fraction; NFF).
Data were collected from 67 in-hospital arrests. The researchers found that analysis of the first 5 minutes of each resuscitation by 30 second segments revealed that chest compression rates were less than 90 compressions per minute in 28.1 percent of segments. Compression depth was too shallow for 37.4 percent of compressions. Ventilation rates were high, with 60.9 percent of segments containing a rate of more than 20/min. A total of 27 patients (40.3 percent) achieved return of spontaneous circulation and 7 (10.4 percent) were discharged from the hospital.'"/>