Several years ago studies out of Arizona and Wisconsin trumpeted continuous cardiac compressions, known as CCC or sometimes known as CCR (cardiocerebral resuscitation), as offering increased survival for out of hospital cardiac arrest. Neurologically intact survival from witnessed vfib arrests increased by 250-300%. For the first several cycles of CPR stop compressions only to shock, insert an oral airway and apply a nonrebreather, ventilate passively. It made sense. You had to keep the heart perfused and avoid hyperventilation. CCR has spread across the country like wildfire. Here in Connecticut, we have made it our statewide standard for all arrests of suspected cardiac origin. The AHA ignored CCR in 2010 and in the just released 2015 Guidelines offered tepid support for it, giving it a IIb recommendation. (A IIb recommendation means the evidence is WEAK, but it may be reasonable to practice the method. A IIa recommendation means MODERATE evidence, is reasonable to do. A Level I recommendation is STRONG evidence, is recommended.)
2015 (New): For witnessed OHCA with a shockable rhythm, it may be reasonable for EMS systems with priority based, multitiered response to delay positive-pressure ventilation (PPV) by using a strategy of up to 3 cycles of 200 continuous compressions with passive oxygen insufflation and airway adjuncts.
Yesterday, the New England Journal of Medicine published a major study, Trial of Continuous or Interrupted Chest Compressions during CPR, the result of a major randomized controlled study comparing CCC with standard CPR. The results not only showed continuous chest compressions without pause for ventilations did not improve outcome, these patients did slightly worse. Now, it is important to note they did not compare true CCR, with passive ventilation, with standard CPR. They compared continuous cardiac compressions with positive ventilation with standard CPR, compressions with pauses for ventilation. Are perhaps the positive pressure ventilations the villian?
12,653 patient received continuous compressions versus 11,0587 getting tradition CPR. 9% of the patients survived to discharge in the continuous compression group versus 9.7% in the standard group, a difference considered not statistically significant. No small study here. Both groups had very high chest compression rates . The new AHA guidelines recommend a compression fraction of .60. Here the CCC group was .83 and the traditional group was .77. The fraction means amount of time per minute compressions are being performed.
An accompany editorial Continuous or Interrupted Chest Compressions for Cardiac Arrest, concludes: â€œThe new 2015 AHA resuscitation guidelines were published only recently. If the results of the current ROC study had been available, the guidelines committee might have decided to retain the previous recommendation to give chest compressions interrupted for ventilations and perhaps even to upgrade that recommendation to a class IIa recommendation for EMS providers. Should the AHA reconsider their recommendation?
The AHA has put an end to its five year cycle of updates so they can update the recommendations more rapidly to take into account the best and latest scientific evidence. It will be curious to see what happens here. I think we also need to allow some time for other people to review this study for any methodological errors. Give it the closest scrutiny.
A final thought. We must applaud this study and the rigorous debate that should surround it. We have to believe first in science, not in anecdote, theory or wishful thinking. Over the years how many next best things have bitten the dust when finally studied properly? How many things are we doing now that may be harmful? That if only properly studied we would end their practice? So hats off to science, and evidenced based debate. We in EMS should welcome them to town.