天博体育

The advice to 鈥渒eep it simple, stupid鈥濃�攌iss, kiss鈥攕eems to apply to cardiopulmonary resuscitation (CPR).

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

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

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

And the lead story in this month鈥檚 天博体育 Letter is about simplifying CPR.

The trick with 鈥渉ands-only鈥� CPR, as it is sometimes called, is to聽push hard and fast (about 100 times a minute)鈥攁nd聽not to stop until聽professional emergency help聽arrives.

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

A recap of the聽JAMA study

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

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

The study聽included聽5,272聽聽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聽heart trouble.

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

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

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

So 鈥渘o CPR鈥� was the biggest category, although聽the percentage of聽 Arizonans聽who received 鈥渂ystander鈥� CPR聽did increase over the four years included in the聽study,聽from聽28.2% in 2005 to 39.9% in 2009.

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

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

• No 鈥渂ystander鈥� CPR: 5.2% (150 out of 2,900)
• Conventional CPR: 7.8% (52 out of 666)
• Chest compression鈥搊nly 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鈥搊nly CPR was associated with increased survival compared with conventional CPR and no CPR.

Why chest compression-only CPR may be better

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

• It鈥檚聽almost certainly聽easier to聽teach and learn than conventional CPR.
• It would probably make many people more willing to attempt CPR.
• And perhaps most importantly, it聽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鈥檚 mouth.

Here聽is how聽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 鈥減ush hard, push fast, don鈥檛 stop鈥� 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鈥檚 complicated

Still, there鈥檚聽some question whether聽chest compression鈥攐nly CPR聽is really better than聽the聽old-fashioned CPR we learned through聽close encounters with .

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

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

Now for those exceptions

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

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

Most cardiac arrests are聽of cardiac origin, and the Arizona study was limited to those cases.聽But聽people do聽suffer cardiac arrest secondary to other causes, often after聽they stop breathing.聽When that happens,聽聽oxygen levels in the blood get very low.聽Conventional CPR聽and those breaths into the lungs聽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聽cardiac arrest. And if a child suffers cardiac arrest, it鈥檚聽usually preceded by respiratory distress of some kind.