We have been talking about the upcoming changes in resuscitation guidelines during the past several months and the information was finally released, first online at the American Heart Association Journal of Circulation and then live at the Resuscitation Science Symposium (ReSS) that was held this past weekend in Chicago. There were several themes that emerged during the presentations, along with the discussions and debate that occurred among the attendees.
Let’s first focus on the basics, since it has become pretty clear that no advanced life support intervention will work without an incredibly strong foundation in basic life support. Most of us have already known that the AHA has formally renounced the concept of checking airway first, followed by breathing then circulation (ABC) and has replaced it with CAB: If no sign of life is observed, and no pulse is present after 10 seconds, begin compressions first after activating 911 and getting an AED to the patient’s side.
Providing ventilations comes second; for adult sudden cardiac arrest victims, it’s likely that there will be adequate amounts of oxygen in the blood for some time. The exception is for pediatric patients, since hypoxia is often a cause of cardiac arrest in children. If you are alone with the child, begin “conventional CPR” for two minutes, then run for help.
Chest compressions for adults are now provided at a rate of at least 100 times per minute, and at a depth of at least 2 inches. These guideline changes are subtle but they signify the concern that compressions are still being done without adequate rate or depth. How fast is too fast, and how deep is too deep is a matter of debate; realistically going any faster than 120 beats per minute is likely to tire people prematurely. Likewise, pushing down two inches will already take significant strength to do it consistently.
Early defibrillation is still emphasized. The sooner the patient can be defibrillated, the more likely the conversion — especially if compressions are being performed prior to the shock. Since coronary artery pressure falls rapidly when no compressions are being performed, and it takes significant time to bring it back up to perfusing levels, the delay between application, analysis and shock must be very short — ten seconds or less.
The technology of the AED has to be able to match that — meaning that it has to be able to analyze while CPR is in progress. If a shock is needed, keep compressing until just before delivering the shock.
There is finally a real emphasis to match reality — professional rescuers work in teams to perform resuscitation. I am hoping that when the new training courses are released, there will be training emphasis in this concept, rather than delegation from a single leader.
Another theme from the conference is that the science of resuscitation is really beginning to get a handle on how to coax a heart back to life. It’s the ability to restore the brain back to normal function that is the challenge. Post-resuscitation is now a link in the chain of survival and there were multiple presentations on the research occurring in this fascinating area. I will expand upon this in an upcoming column. Here’s a teaser though; it’s possible we might be killing the brain while we are saving the heart. Any ideas why?
