# New CPR



## tomahawk6 (6 Sep 2007)

http://news.uns.purdue.edu/x/2007b/070905GeddesCPR.html

New CPR promises better results by compressing abdomen, not chest

A biomedical engineer at Purdue University has developed a new method to perform cardiopulmonary resuscitation that promises to be more effective than standard CPR because it increases nourishing blood flow through the heart by 25 percent over the current method.

A new technique is desperately needed because conventional CPR has a success rate of 5 percent to 10 percent, depending on how fast rescuers are able to respond and how well the procedure is performed. For every one minute of delay, the resuscitation rate decreases by 10 percent.


"In other words, at 10 minutes, the resuscitation is absolutely ineffective," said Leslie Geddes, Showalter Distinguished Professor Emeritus in Purdue's Weldon School of Biomedical Engineering. "Any medical procedure that had that low a success rate would be abandoned right away. But the alternative is not very good, either: Don't do CPR and the person is going to die."

Geddes has developed the first new CPR alternative, called "only rhythmic abdominal compression," or OAC-CPR, which works by pushing on the abdomen instead of the chest.

"There are major problems with standard CPR," Geddes said. "One is the risk of breaking ribs if you push too hard, but if you don't push hard you won't save the person. Another problem is the risk of transferring infection with mouth-to-mouth breathing."

The new CPR method eliminates both risks, Geddes said.

Findings will be detailed in a research paper appearing this month in the American Journal of Emergency Medicine, published by Elsevier Inc. The paper was authored by Geddes and his Purdue colleagues Ann E. Rundell, assistant professor of biomedical engineering, biomedical engineering doctoral student Aaron Lottes, and basic medical sciences graduate students Andre Kemeny and Michael Otlewski.

In standard chest-compression CPR, which has been in practice since the 1960s, the rescuer pushes on the chest and blows into the subject's mouth twice for every 30 chest compressions. However, the risk of infection is so grave that many doctors and nurses often refuse to administer mouth-to-mouth resuscitation. In one 1993 study of 433 doctors and 152 nurses, 45 percent of doctors and 80 percent of nurses said they would refuse to administer mouth-to-mouth resuscitation on a stranger.

"This is the real world that nobody knows about, and it's a sobering thought," Geddes said.

OAC-CPR eliminates the need to perform mouth-to-mouth resuscitation. 

The American Heart Association requires that rescuers administering CPR push with enough force to depress the chest 1 and a half to 2 inches at a rate of 100 times per minute.

"To depress the chest 1.5 to 2 inches takes 100 to 125 pounds of force," Geddes said. "So you have to push pretty hard and pretty fast, and two people are needed to perform it properly. One blows up the lungs and the other compresses the chest. And when the one who's compressing the chest gets tired, they change positions."

OAC-CPR requires only one rescuer.

Instead of two breaths for every 30 chest compressions, the new procedure provides a breath for every abdominal compression because pushing on the abdomen depresses the diaphragm toward the head, expelling air from the lungs. The release of force causes inhalation.

Researchers have known since the 1980s that pushing on the abdomen circulates blood through the heart. The idea was originated by Purdue nursing doctoral student Sandra Ralston, Geddes said.

"She made the remarkable observation that if you pushed on the abdomen after each chest compression you could double the CPR blood flow," he said. "So I started thinking, what would happen if you just pushed on the abdomen and eliminated chest compression entirely?"

The procedure provides a new way to effectively perform "coronary perfusion," or pumping blood through the heart muscle, which is critical for successful resuscitation because the heart muscle is nourished by oxygenated blood, Geddes said.

"Unfortunately, in standard chest-compression CPR, blood sometimes flows in the wrong direction, which means the coronary blood flow goes backward, bringing de-oxygenated blood back into the heart muscle," Geddes said. "This retrograde flow reduces the likelihood of resuscitation."

Findings showed that OAC-CPR eliminates this backward flow.

The Purdue researchers compared coronary artery blood flow during standard chest-compression CPR with the flow resulting from only abdominal compression CPR. Findings showed that using the new method and pushing with the same force recommended for standard CPR provided 25 percent more blood flow through the heart muscle without retrograde flow in the coronary arteries.

The researchers followed the standard recommended by the American Heart Association, pushing with 100 pounds of pressure 100 times per minute.

"With OAC-CPR, you really don't have to press as hard or as often, but we followed the American Heart Association standard to avoid possible criticism from people who could have said we didn't observe the standard," Geddes said.

Another benefit of OAC-CPR is that it eliminates rib fractures, which are commonly caused by compressing the chest. Rib fractures cause the chest to recoil more slowly, but effective CPR requires that rescuers wait until the chest recoils fully before compressing.

Geddes created a wooden "pressure applicator" that resembles a scaled-down version of a baseball home plate. It is contoured so that it can be used to compress the abdomen without pushing on the ribs. However, a rescuer could push with the hands to perform the procedure if no applicator were available.

Abdominal organs contain about 25 percent of the total blood volume in the body.

"You can squeeze all of that into the central circulation when you press on the abdomen," Geddes said.

Whether the procedure gains widespread acceptance depends on whether other researchers can duplicate the results.

"In research, you publish data and then the scientific community looks at the data and tries to duplicate it to verify that it works," said Geddes, who was awarded the National Medal of Technology from President George W. Bush in a White House ceremony on July 27. It is the nation's highest honor for technological innovation.

The research was funded by the Purdue Trask Fund.

Elsevier is a global business headquartered in Amsterdam, The Netherlands, and has offices worldwide. Elsevier is part of Reed Elsevier Group plc (http://www.reedelsevier.com/), a world-leading publisher and information provider. Operating in the science and medical, legal, education and business-to-business sectors, Reed Elsevier provides high-quality and flexible information solutions to users, with increasing emphasis on the Internet as a means of delivery.


Writer: Emil Venere, (765) 494-4709, venere@purdue.edu


Source: Leslie Geddes, (765) 494-2997, geddes@ecn.purdue.edu

ABSTRACT

A New CPR Method Employing Only Rhythmic Abdominal Compression 

L.A. Geddes ME, PhD, DSc, FACC, FRSM1, A. Rundell, PhD2, A. Lottes BCh, MBA, PhD3, A. Kemeny MS4, M. Otlewski BS4 - *Supported by the Purdue Trask Fund

1- Showalter Distinguished Professor Emeritus; 2- Assistant Professor of Biomedical Engineering; 3- Graduate, Weldon School of Biomedical Engineering, Purdue University; 4- Graduate student, Basic Medical Sciences, Purdue University 

This paper introduces two new CPR concepts: 1) the use of only rhythmic abdominal compression (OAC) to produce blood flow during CPR with ventricular fibrillation (VF) and 2) a new way of describing coronary perfusion effectiveness, namely the area between the aortic and right-atrial pressure curves, summed over one minute, the units being mm Hg-sec. We call this unit the coronary perfusion index (CPI). True mean coronary perfusion pressure (CPP) is CPI/60. We also relate CPI during CPR with VF to the CPI for the normally beating heart in the same animal, obtained prior to each experiment. This 11-pig (25-35 kg) study compares the CPI for standard chest-compression CPR and that obtained with OAC-CPR. The coronary perfusion ratio for OAC-CPR compared to standard chest-compression CPR was 1.6± 0.73, P=0.024. In other words OAC-CPR produced 60% more coronary perfusion than standard chest-compression CPR, with no damage to visceral organs.


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## Greymatters (6 Sep 2007)

Now EVERYBODY has to retrain!


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## Colin Parkinson (6 Sep 2007)

We used to point out to people that were worried about doing CPR on someone, that you only did CPR on someone that was already dead, therefore the outcome could only get better. CPR with 02 can be very effective. We found that bridge jumpers that responded to CPR usually died of lung infections a few days later, however the families are generally grateful to have a chance of saying goodbye. We also did CPR on a couple of people who we knew were quite dead (1 hr submersion) because the persons kids were watching and it made them feel that everything that could be done, was done.


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## Blackadder1916 (6 Sep 2007)

The researchers of this present an interesting procedure, but there is a long way to go before acceptance.  Reading the article, though, did bring to mind my early first aid training when we had to demonstrate manual artificial respiration methods such as Silvester and Holger Neilsen.  (Anybody else also remember Shafer and Emerson methods?)  In reading that the researchers used a "pressure applicator" to achieve uniform compression on the abdomen, it made me wonder that perhaps the old method of 'barrel rolling' had its (very limited) success due to more than restoring respiration.


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## Armymedic (6 Sep 2007)

And what of obese and pregant cas?

Definately more trials req'd.


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## MedicStudent (6 Sep 2007)

Definitely an interesting study. There are two things that I noticed in my first read of the post that I wanted to comment on though. One is that they mention breaking ribs if you push too hard. I don't know if these researchers have ever done CPR in real life (or CPR in real life on an elderly person) but it is very possibly to break ribs without pushing too hard. The other thing is that they mention how reluctant health care providers are to provide mouth to mouth to a stranger without mentioning that current CPR can be done using a barrier device. Problem solved.


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## Colin Parkinson (6 Sep 2007)

Considering the high percentage of people getting CPR are older people, breaking ribs is quite common. the problem with a mask is actually having one on you during the incident, unless you are a equipped first responder or in a hospital, there is a good chance that you may have to make the choice on to do CPR or not. It would be nice to have two different methods to able to use them as conditions warrant.


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## kj_gully (7 Sep 2007)

Actually,my understanding is that the studies show that the pause to ventilate with 16% o2 is actually detrimental, and the indirect exhange of 21% o2 via the chest compressions is more effective. the constant circulation of blood is more valuable than a start and stop, and the blood gets oxygen as the lungs bellow. ( not below, bellow, like a blacksmith's bellows). The not touching tongues is just a side benefit.


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## Greymatters (7 Sep 2007)

kj_gully said:
			
		

> The not touching tongues is just a side benefit.



 :rofl:

But on a serious note, this would reduce concerns over mouth-to-mouth and possible contraction of communicable diseases.  Also, the 'pocket mask' companies will likely go out of business if this gets widely approved... which reminds me, guess thats one less thing to worry about carrying around, isnt it?


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## medicineman (8 Sep 2007)

I seem to recall an idea a number of years back of a 3 rescuer approach where by there was a third person compressing the abdomen in alternating synch with the chest compressor to get blood out of the abdomen.  This new method could be interesting to try, as you'd have to generate enough pressure to open the heart valves up enough for the blood to get in and escape, not to mention getting it to the lungs and brain and wherever else it's needed.  That's pushing pretty hard, pretty often, with not alot of let up.  And as SMMT stated, given that the people out there with FBS or with human abdominal parasites have alot in the way, will be that much harder.  As for the assertion that CPR is useless as a resucitation tool, the people writing the article still fail to note that CPR as a rule is a bridge and not a heart starting tool in and of itself (so I guess in the strictest sense they are correct, but they of course haven't stated the whole truth).  But that's another story I suppose.

MM


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## X Royal (9 Sep 2007)

MedicStudent said:
			
		

> The other thing is that they mention how reluctant health care providers are to provide mouth to mouth to a stranger without mentioning that current CPR can be done using a barrier device. Problem solved.


What they also do not mention is that in the vast majority of cases that health care providers will have access to some form of PPV device (Bag-Valve-Mask being most common) & medical oxygen. This choice will be used over mouth to mouth (protected or not) almost every time.


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## psychmurse (15 Feb 2009)

I am a current CPR instructor, and our current program (30 compressions to 2 breaths) at the rate of 100 compressions /minute is almost due to be revised again.

Part of that revision is looking at what other areas are doing, and I think it's Australia that does no rescue breathing, only chest compressions, with good success.

I've also heard that the abdominal compression issue was being looked at as well, but those are just rumors.

What I do know for sure is that the problem with "old" CPR is that you would do 15 compressions, finally start to move blood (if it was done right) on compression 14-15 and then stop... The whole point of "new" CPR is that you compress longer, and actually move blood.

But hey they have to pay someone to research these things, and offer slight changes every 5 years or so, if I had to put money on it I think we'd move to a chest compression only model, and then an abdominal compression model, as people get scared if changes to large are made all at once!


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## david_wright (21 Feb 2009)

We do 30:2 in Australia. We follow the ILCOR guidelines as I am sure you do.
There is no need for rescue breaths nor if there need to pause and feel the pulse as frequently as has been done in the past.
The move is now earlier defibrillation, greater emphasis on maintaining circulation, and less delays due to breathing.


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## X Royal (7 Mar 2009)

psychmurse said:
			
		

> I am a current CPR instructor, and our current program (30 compressions to 2 breaths) at the rate of 100 compressions /minute is almost due to be revised again.
> 
> Part of that revision is looking at what other areas are doing, and I think it's Australia that does no rescue breathing, only chest compressions, with good success.



I am also a current CPR instructor certified to teach CPR up to the HCP level.
For the lay rescuer no ventilation CPR is currently an option for those uncomfortable with giving unprotected ventilation's.
As for revisions to the current CPR protocols I suspect it will be a least 2011 before any changes are brought out. 

Pro Patria: Rick


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## bradlupa (7 Mar 2009)

At the fire department where i am stationed we run 30:2 with a Bag mask valve in conjuction with defib and o2 depending on the call we usually always use O2, if we are at a VAS (vitial signs absent) usually running 02 at 15l/m.  but this new method will be interesting to see what happens.


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## X Royal (7 Mar 2009)

bradlupa: Where in Ontario are you from as this is not a "_new method_" in Ontario?
Did your department recently convert to a first response role with additional training & equipment to accommodate this role?

Pro Patria


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## old medic (8 Mar 2009)

I believe he means it would be interesting to see the method suggested in the first post. The Purdue University study.


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## X Royal (8 Mar 2009)

old medic: You may be correct as I read the post again. dradlupa's failure to capitalize the "b" in the word "but" lead me to believe it was a continuation of the statement as apposed to a new statement.  

Rick


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## Barts (8 Mar 2009)

As of when I left my (BC) fire dept last summer, we were still using protocols developed in Seattle (IIRC).  2 minutes of uninterrupted compressions at 100/min per rescuer then switch.  Second rescuer with BVM would time their 'squeeze' with the recoil phase of the chest, every 10th compression.  It maintained circulation for a much greater time, and the appropriate timing of the 'breaths' didn't interfere with compressions.  For the lay rescuer, the ventilations are dropped, as there's enough air moving already.

It was a heck of a workout on remote calls.

I'm going to echo the concern about obese or pregnant patients.  How would this new protocol address them?


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## Pea (8 Mar 2009)

Barts said:
			
		

> As of when I left my (BC) fire dept last summer, we were still using protocols developed in Seattle (IIRC).  2 minutes of uninterrupted compressions at 100/min per rescuer then switch.  Second rescuer with BVM would time their 'squeeze' with the recoil phase of the chest, every 10th compression.  It maintained circulation for a much greater time, and the appropriate timing of the 'breaths' didn't interfere with compressions.  For the lay rescuer, the ventilations are dropped, as there's enough air moving already.
> 
> It was a heck of a workout on remote calls.



This is the same protocol I was following this past fall in BC. We were also using a device on the BVM that would light when we were supposed to breathe for the patient in some areas as part of a study.


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## bradlupa (9 Mar 2009)

I do apologize for my grammatical errors.

I’m stationed in Port Hope, Ontario at station #3.

I was referring to the Purdue study.  As I think that it will bring some interesting articles out about the ways we do CPR.

Yes we had to have training.  We took a First Responder course (Basic Life Support Pro). This course allows use to administer O2 and insert airways and a few other things.  But those are the most common things that we do.  We run about 1000 calls/year and about 70% are medical assists, meaning that if the ambulance is more than 5mins away we are toned out.  Unless it is an accident the we are automatically tone with ambulance.  

As for the Defib, we had to take an 8 hour course, and we have to be recertified every four months.


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## kj_gully (22 Mar 2009)

medicineman said:
			
		

> I seem to recall an idea a number of years back of a 3 rescuer approach where by there was a third person compressing the abdomen in alternating synch with the chest compressor to get blood out of the abdomen.  This new method could be interesting to try, as you'd have to generate enough pressure to open the heart valves up enough for the blood to get in and escape, not to mention getting it to the lungs and brain and wherever else it's needed.  That's pushing pretty hard, pretty often, with not alot of let up.  And as SMMT stated, given that the people out there with FBS or with human abdominal parasites have alot in the way, will be that much harder.  As for the assertion that CPR is useless as a resucitation tool, the people writing the article still fail to note that CPR as a rule is a bridge and not a heart starting tool in and of itself (so I guess in the strictest sense they are correct, but they of course haven't stated the whole truth).  But that's another story I suppose.
> 
> MM



Watching the news the other day- the footage of the aftermath of an RCMP shooting showed BC paramedics using this technique- at least to my eyes. Anyone know if they are trialling this, or have adopted it for their protocol?http://canwest.a.mms.mavenapps.net/mms/rt/1/site/canwest-globalbc-pub01-live/current/launch.html?maven_playerId=globalbcallvideo&maven_referralPlaylistId=24845d5c80768d2d50c292ff8e60a971d5a69e38&maven_referralObject=3901495&maven_referrer=staf Not too sure if this will work, or how long t will stay live...


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## medic45 (22 Mar 2009)

Nope.  That was just the guys belly jiggling.  I think someone was also putting some pressure on a bleed at some point too which could explain it.  That arrest was D/C pretty quick as the ACP shown in the clip made a patch to the hospital.  That guy was dead at the scene.  That's what happens when you pull a knife on a cop and get rounds center mass.  

We are running 2 cardiac arrest studies here right now with the ROC group.  One is the Analyze early/Late arm and the other is using the impedance threshold device that mediPea noted in her post.  Both of these have trauma as a contraindication to enrollment.


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