BP and CPR

[AnthonyM83]

Hey all,

Could we discuss the relationship between BP and CPR?

I was taught that as you do CPR, it builds up a blood or perfusion pressure that helps circulate blood through the patient's vessels allowing for air exchange. The reason to reduce interruptions in compressions is that it takes awhile for the pressure to build backup and get maximum blood flow going (as maximum as you're going to get with CPR, anyway).

In another forum, I'm being challenged by someone says there isn't really a relation between the two. The point of CPR is blood circulation, but not blood pressure.

I would argue that maintaining a blood pressure is also important (or at very least related) because BP relates to quality of perfusion. Measuring BP is also common in research papers when measuring effectiveness of CPR methods. I've also been given stats on how much BP drops per 5second pause in CPR and how long it takes for pressure to build back up to maximum after a short break in CPR. This would indicate to me that maintaining BP is important or at very least related.

Also, taking a step back and just thinking about it (non-scientifically, just conceptually) it makes sense that higher BP would mean better perfusion of vital organs including brain. You could give continuous compressions at rate of 50/min and you'd be circulating blood, but is simple circulation enough?

How did everyone else here learn it?

[ERDoc]

Hey all,

Could we discuss the relationship between BP and CPR?

I was taught that as you do CPR, it builds up a blood or perfusion pressure that helps circulate blood through the patient's vessels allowing for air exchange. The reason to reduce interruptions in compressions is that it takes awhile for the pressure to build backup and get maximum blood flow going (as maximum as you're going to get with CPR, anyway).

In another forum, I'm being challenged by someone says there isn't really a relation between the two. The point of CPR is blood circulation, but not blood pressure.

I would argue that maintaining a blood pressure is also important (or at very least related) because BP relates to quality of perfusion. Measuring BP is also common in research papers when measuring effectiveness of CPR methods. I've also been given stats on how much BP drops per 5second pause in CPR and how long it takes for pressure to build back up to maximum after a short break in CPR. This would indicate to me that maintaining BP is important or at very least related.

Also, taking a step back and just thinking about it (non-scientifically, just conceptually) it makes sense that higher BP would mean better perfusion of vital organs including brain. You could give continuous compressions at rate of 50/min and you'd be circulating blood, but is simple circulation enough?

How did everyone else here learn it?

You are right and wrong. The new CPR guidelines emphasize compressions in order to build up coronary perfusion pressure, not necessarily peripheral blood pressure. Perfusing the coronaries (and in turn the heart) is a good thing. A well perfused heart is usually a well oxygenated heart (hopefully). A well oxygenated heart is more likely to respond to the totures we place on it such as electrocution and chemistry. It also helps keep the brain perfused better (but the AHA guielines are written by cardiologists and in their world, nothing exists outside of the chest). Here are a few articles that may be of interest.

http://www.ncbi.nlm.nih.gov/entrez/query.f...l=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/query.f...l=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/query.f...l=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/query.f...l=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/query.f...l=pubmed_DocSum

http://www.ncbi.nlm.nih.gov/entrez/query.f...l=pubmed_docsum

That should keep you entertained for a while. There are a few other good papers out there. Check the references from these papers or go to pubmed.

[Ridryder 911]

Let's keep it simple BP= C.O. X HR X T.P R. Which in cardiac arrest you have ONLY have the compression perfusion, you have NO true cardiac heart rate again for except the compression from an outside source and peripheral resistance is greatly depressed because of lack of muscle tone except from medication(s). So reality the pressure one would obtain is not really the patients pressure, rather only perfusion pressure of outside source. The same as if the patient was on a bypass machine. Circulation pressure, not the true patients pressure.

If one wants to remove all doubt of having knowledge of resuscitation measures; just take a peripheral blood pressure in a cardiac arrest. Again, because one is only getting a pressure from the compressions (or perfusion) being performed at the time.

For one to get an a true accurate blood pressure from the compressions to measure coronary artery pressure an arterial line would have to be placed in and measure a true and accurate pressure of coronary circulation and cerebral perfusion. Which coronary pressure should be at 40 torr and slightly higher for cerebral perfusion. The same philosophy for shock therapy, and the debate over raising pressure more would cause more detrimental problems. If one does not have high enough pressure for cerebral perfusion, in ethical debate, what good are we doing, producing a brain damaged patient ?

I doubt you will see intraarterial lines even considered, unless one was already in place prior to arrest state. Costs, plus having to have damn good blow flow to cannulate the line. Why?

Theoretical thinking is great, not always practical. As more and more studies are revealing once the patient is in cardiac arrest state one needs to determine how much resuscitation measure should even be performed. Since results of cardiac arrest is dismissal to say the least (in hospital < 15% ). Emphasis should be placed on pre-cardiac arrest phase.

R/r 911