We’ve a new study this week, appearing in the American Heart Association’s journal Circulation that looks at the survivability of OHCA (Out of Hospital Cardiac Arrests) with non-shockable rhythms utilizing the new CPR guidelines that stress chest compressions.
Non-shockable cardiac arrest arrhythmias are asystole (flat line) and PEA (Pulseless Electrical Activity) – what we used to call back in the stone age of EMS, electromechanical dissociation.
Neither of which respond to defibrillation.
Thirty-five years ago, most cardiac arrests started out with either pulseless ventricular tachycardia or (worse) ventricular fibrillation (both shockable rhythms) - that if not corrected - rapidly progressed to PEA or Asystole and ultimately death.
Which is why EMS put such emphasis on getting paramedics equipped with defibrillators and cardiac meds onto ambulances starting in the early 1970s.
But in recent years – for reasons that are not altogether understood – the number of shockable cardiac arrests is on the decline, while incidence of PEA and asystole are rising (see JEMS article “Where Has V Fib Gone: Why today’s EMS crews see less ventricular fibrillation in the field.”)
Some researchers propose that better detection and earlier treatment of coronary artery disease may be responsible for this pendulum swing.
But with these gains come questions over whether the new standards for CPR – first unveiled in 2005 - work as well for non-shockable cardiac arrests.
Which brings us to the study, published earlier this week in the journal Circulation. You’ll find excerpts from the abstract below, but follow the link to read it (or the entire study) in its entirety.
Peter J. Kudenchuk1; Jeffrey D. Redshaw; Benjamin A. Stubbs; Carol E. Fahrenbruch; Florence Dumas; Randi Phelps; Jennifer Blackwood; Thomas D. Rea; Mickey S. Eisenberg
Background—Out-of-hospital cardiac arrest (OHCA) claims millions of lives worldwide each year. OHCA survival from shockable arrhythmias (ventricular fibrillation/tachycardia) improved in several communities after implementing American Heart Association resuscitation guidelines that eliminated "stacked" shocks and emphasized chest compressions. "Non-shockable" rhythms are now the predominant presentation of OHCA, upon which the benefit of such treatments is uncertain.
Conclusions—Outcomes from OHCA due to non-shockable rhythms, though poor by comparison with shockable rhythm presentations, improved significantly after implementing resuscitation guideline changes, suggesting their potential to benefit all presentations of OHCA.
For more on all of this, we have the press release from the American Heart Association.
April 02, 2012
- CPR can save someone with cardiac arrest even if they don’t respond to a defibrillator.
- People with non-shockable cardiac arrest are more likely to live if they receive CPR based on recent guidelines emphasizing chest compressions.
- The American Heart Association’s CPR guidelines emphasizing chest compressions are saving more lives, according to a new study.
DALLAS, April 2, 2012 — People who have a cardiac arrest that can’t be helped by a defibrillator shock are more likely to survive if given CPR based on updated guidelines that emphasize chest compressions, according to research reported in the American Heart Association journal, Circulation.
“By any measure — such as the return of pulse and circulation or improved brain recovery — we found that implementing the new guidelines in these patients resulted in better outcomes from cardiac arrest,” said Peter J. Kudenchuk, M.D., lead author of the study and professor of medicine at the University of Washington in Seattle, Wash.
The American Heart Association changed its CPR guidelines in 2005 to recommend more chest compressions with fewer interruptions. The emphasis on chest compressions continued in the 2010 guidelines update.
All of which illustrates the importance of learning how to do effective CPR.
Luckily, today CPR is easier to do than ever.
Compression-only CPR is now the standard for laypeople, and so you don’t have to worry about doing mouth-to-mouth.
While it won’t take the place of an actual class, you can watch how it is done on in this brief instructional video from the American Heart Association.
A CPR class only takes a few hours, and it could end up helping you save the life of someone you love.
For more on the recent changes to bystander CPR, you may wish to visit these recent blogs.