Nonshockable Rhythms and CPR
When applied early, correctly and followed up with a defibrillator, chances of survival can increase to 75 percent or more.
What about non-shockable rhythms; will CPR still increase the chances of survival?
University of Washington professor, Dr. Peter Kudenchuk and his team from Seattle analyzed thousands of patients who suffered a cardiac arrest with non-shockable rhythms and found a strong correlation between high-quality chest compressions and survival rates for people in cardiac arrest, even if they do not response to defibrillator shocks.
Types of Rhythms
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Dr. Kudenchuk discovered patients had a 50 percent better chance of regaining spontaneous circulation, a 56 percent better chance of a favorable neurological outcome, and an 85 percent better chance of living one year.
“Why the study is important is that a huge emphasis has been placed on treating patients with shockable arrhythmias. That’s why these public-access defibrillators and rapid shock methods have evolved and been promoted and rightly so, but shockable rhythms account for only a small proportion of cardiac arrests,” says Kudenchuk.
Non-shockable cardiac arrest, including asystole and so-called pulseless electrical activity, represent a large portion of sudden cardiac-arrest cases, up to 75 percent, but this is the first study to rigorously check whether CPR could improve survival in for people with non-shockable rhymes.
All of the patients in the study were determined to have a nonshockable arrhythmia after the responders tried to defibrillate their hearts. “These patients do very poorly, because the only real therapies we have to throw at them are CPR and drugs and trying to find something reversible that may have caused the rhythm,” Kudenchuk says.
All of the patients in this study were in Washington State from 2000 to 2010, so the study was able to compare outcomes of patients before and after the release of the 2005 American Heart Association CPR guidelines that encourage uninterrupted chest compressions. Kudenchuk was then able to compare historical methods to up-to-date methods focusing on uninterrupted chest compressions.
Kudenchuk explained that the current CPR guidelines “provide a stronger emphasis on ongoing minimally interrupted CPR and to reduce the time that a patient is in cardiac arrest and the hands are not actively pumping the chest. In simply deploying those guidelines–there is nothing magical about it–you can almost double survival from a non-survivable disease, and that is nonshockable cardiac arrest.”