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Kiss-kiss CPR: The mouth-to-mouth part may not be needed

Posted By Peter Wehrwein On October 5, 2010 @ 4:03 pm In Health,Heart Health | Comments Disabled

The advice to “keep it simple, stupid”—kiss, kiss—seems to apply to cardiopulmonary resuscitation (CPR).

But with CPR, kiss-kiss means no mouth-to-mouth contact.

A study published in tomorrow’s Journal of the American Medical Association (JAMA) adds to the evidence that the old way of doing CPR—alternating chest compressions with blows into the mouth—is needlessly complicated in most cases (there are exceptions, which we will get into below).

Instead, this study and others (The New England Journal of Medicine published two CPR studies in July, one conducted in Sweden and the other in the Seattle area) suggest that CPR is just as effective, and maybe more so, when people skip the mouth-to-mouth ventilations and do only the chest compressions.

And the lead story in this month’s Harvard Health Letter is about simplifying CPR.

The trick with “hands-only” CPR, as it is sometimes called, is to push hard and fast (about 100 times a minute)—and not to stop until professional emergency help arrives.

You definitely want that help to arrive as soon as possible, so if you think someone has had a heart attack or that his or her heart has stopped, the very first priority is to call 911. (Cell and smartphones have made that easier than ever to do: no more running around, looking for a pay phone.)

A recap of the JAMA study

The data for the JAMA study came from Arizona, and the study was led by Dr. Bentley J. Bobrow, the medical director of the bureau for emergency medical services and trauma systems for the Arizona Department of Health Services.

Dismayed by cardiac arrest survival statistics, health officials in the Grand Canyon State  launched the Save Hearts in Arizona Registry and Education (SHARE) program in 2005. The program used public service announcements, online videos, training programs, and a variety of other means to familiarize Arizona residents with hands-only CPR and encourage them to do it if someone was in need.

The study included 5,272  Arizona adults (people ages 18 and older) who between Jan. 1, 2005, and Dec. 31, 2009 had an out-of-hospital cardiac arrest that presumably was triggered by heart trouble.

After exclusions because of missing information, CPR being administered  by a medical professional, and a variety of other reasons, the number of cases included in the analysis was 4,415.

Here is how the numbers broke down by the type of CPR delivered:

  • 65.7% (2,900) received no CPR prior to professional help arriving
  • 15.1% (666) received conventional CPR (the chest compressions and the breaths)
  • 19.2% (849) received chest compression–only CPR

So “no CPR” was the biggest category, although the percentage of  Arizonans who received “bystander” CPR did increase over the four years included in the study, from 28.2% in 2005 to 39.9% in 2009.

The proportion of people who received chest compression–only CPR also increased. In 2005,  just 33 out of the 596 (5.5%) cases in the study received chest compression–only CPR. By 2009, 306 out of 1,011 (30%) did.

Here is how the survival statistics stacked up (survival in this context means living long enough to be discharged from the hospital):

  • No “bystander” CPR: 5.2% (150 out of 2,900)
  • Conventional CPR: 7.8% (52 out of 666)
  • Chest compression–only CPR: 13.3% (113 out of 849).

And the overall survival rate was 7.1% (315 out of 4,415).

So the conclusion drawn was that chest compressions–only CPR was associated with increased survival compared with conventional CPR and no CPR.

Why chest compression-only CPR may be better

In an editorial about the Arizona study, Dr. David C. Cone, an emergency department doctor at Yale (he is not the former major league baseball pitcher, David B. Cone), summed up some of the  arguments  for chest compression-only CPR.

  • It’s almost certainly easier to teach and learn than conventional CPR.
  • It would probably make many people more willing to attempt CPR.
  • And perhaps most importantly, it keeps the blood flowing through the circulation system, which in many cases is probably going to be more important than resupplying the blood with oxygen by blowing into the person’s mouth.

Here is how Dr. Cone put it in his editorial:

Forward flow of blood ceases very soon after chest compressions are halted, and several compressions are needed to reestablish perfusion when compressions are resumed. The “push hard, push fast, don’t stop” mantra of current CPR teaching is designed to reinforce the need for minimal interruptions in chest compressions to maintain some degree of perfusion to the vital organs until more definitive therapy (such as defibrillation) can be delivered.

But it’s complicated

Still, there’s some question whether chest compression—only CPR is really better than the old-fashioned CPR we learned through close encounters with Resuscitation Annie.

The studies published in the NEJM suggested equivalence between the two forms of CPR, not superiority for the hands-only approach. But equivalence is often seen as a mark in the plus column for chest compression–only CPR because it’s presumably so much easier to learn and do. And the Arizona experience does suggest that if chest compression—only CPR  became the norm, more people would attempt CPR.

The survival statistics from Arizona are certainly a nod in favor of chest compression–only CPR. But Dr. Cone argues that when neurological outcomes were factored in, it’s closer to being a tie between conventional and chest compression–only CPR.  Neurological outcomes are key because one of the main goals of CPR is to keep the brain supplied with blood. But the authors of the study see the data a little differently. They concluded that the neurological outcomes were better for chest compression–only CPR. So perhaps this particular issue needs to be hashed out.

Now for those exceptions

New CPR guidelines from the American Heart Association are due out soon, according to Dr. Cone. We’ll see what the new recommendations have to say (and write another blog post). The long-term trend has been toward simplifying CPR and emphasizing chest compressions.

But as was mentioned at the very beginning of this post, there are cases when conventional CPR with its mouth-to-mouth ventilations is probably going to remain the better approach.

Most cardiac arrests are of cardiac origin, and the Arizona study was limited to those cases. But people do suffer cardiac arrest secondary to other causes, often after they stop breathing. When that happens,  oxygen levels in the blood get very low. Conventional CPR and those breaths into the lungs can bring oxygen levels back up.

When do people stop breathing and then suffer cardiac arrest? When they drown, choke on something, or are strangled by something. A drug overdose can suppress respiration and lead to cardiac arrest. And if a child suffers cardiac arrest, it’s usually preceded by respiratory distress of some kind.

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