Posted by: medicblog999 | April 20, 2009

A new way to think of Resuscitation

Firstly, thank you to those of you that took the time to review my blog. It is very much appreciated (although I still need two more reviews please!!)

————————————————————————————–

heart_brain_thumbnail_3Ive been reading some very interesting literature on Cardio-Cerebral Resuscitation (CCR) recently.

 For those that don’t know about it (me included up until 1 week ago!), this is a method of carrying out what is normally called CPR on a collapsed patient whose heart and breathing have stopped.

I read a post on Rouge Medics blog which mentioned this concept, and due to my inquisitive mind and not liking not knowing something, I thought I would go and do some reading on it. It makes for some very interesting changes in what we would class as a normal resus job and initially, it seems to go against most of what we would consider a necessity to give a patient the best changes of survival. However, once you understand the pathophysiology behind the changes, it all starts to make sense. I will try and give you a brief synopsis of what I have found out, and I will put the links to the papers at the end of the post.

This may be old hat to some of you, especially the American readers, as this seems to have come from over your way and goes back to around 2004. The main paper I have read comes from the American Journal of Medicine (2006) and this certainly seems to have been the focus for the changes in the UK guidelines on resuscitation that we saw in 2005/2006. However, the UK guidelines seem to stop short of implementing the full and complete concept of CardioCerebral resuscitation

To full understand the proposed changes, we need to look at the pathophysiology of a VF arrest. This has been wrote about a number of times recently by various authors and has been broken down into three distinct stages:

  1. The Electrical Phase : This lasts about 4 minutes and is the time when rapid defibrilation is the best hope for a rapid recovery of the patient. We all know that the chances of a staffed paramedic ambulance arriving in time to tackle this phase of a cardiac arrest is slim, which is why there has been such a drive to get first responders trained in AEDs out there.
  2. The Circulatory Phase : This occurs from approximately 4 minutes to 10 minutes. This is usually the time when we arrive on scene. By this time, the chance of a successful defibrilatory shock has likely passed and instead the focus goes to generating sufficient cerebral and coronary blood flow by good and continuous chest compressions. It has been shown that defibrilation prior to chest compressions during this phase causes a higher rate of mortality due to inadequate coronary artery perfusion.
  3. The metabolic Phase: This is associated with cell death and other stages of metabolic derangement. A good prognosis at this stage in virtually non-existent. Various studies however have shown that there may be some benefit in controlled hypothermia for these patients.

Changes already included in the 2005 Uk guidelines were the commencement of chest compressions prior to the first shock for unwitnessed cardiac arrests and also the change to resuming compression immediately after a DC shock is delivered to the patient, rather than stopping for a pulse check. The rationale for this is that if the single shock converts the patients rhythm to asystole or pulseless electrical activity (very regular occurrence), then both of these rhythms require adequate coronary perfusion to convert the the patient to a perfusing rhythm.

The whole purpose of CCR is to ensure continuous pressure to the coronary and cerebral circulation. If hands are taken of the chest for any purpose, the perfusion pressures drop to virtually zero immediately and then take a further period of time to return to their adequate levels.

The biggest change, and that which I am sure will raise the most eyebrows is that in the airway and ventialtion management. What is suggested in CCR is that Rescue breathes and assisted ventialtions during the initial period of EMS cardiac arrest management, are now dropped in preference of an OPA (oropharyngeal airway) and 100% O2 via a non rebreather mask. The rationale for this is that during positive pressure ventilation’s, the intrathoracic pressure is increased which in turn reduces the venous return to the heart, which reduces cerebral and coronary artery perfusion  pressures. Therefore, If you remove these ventilation’s and due to the presence of circulating oxygenated blood present in the blood stream prior to the arrest, the best chance for maintaining perfusing pressures to the heart and brain in these patients is to leave out the positive pressure ventilation (at least in the initial stages)

Limited ventilations may be of some benefit, but studies found that once ventilations were re-introduced into the protocol, most providers ventilated the patient at rates far in excess of the recommended rate.

I had heard of compression only resuscitation before, but I had always assumed this was due to the need for bystanders to do something rather than nothing, as lets face it, not many of us would be willing to plant the lips on someone to do mouth to mouth these days. I would never have thought that there was rationale to actual support this and describe the fact the ventilations may be worse for a patient in cardiac arrest than just putting an O2 mask on!!

There is obviously a whole load more to read on this subject. I have just given you a little taster here. If you would like to read more, please click on the links below.

Cardiocerebral Resuscitation Improves Survival of Patients with Out-of-Hospital Cardiac Arrest
Cardiocerebral Resuscitation – The New Cardiopulmonary Resuscitation
Cardiocerebral Resuscitation – Could this new model of CPR hold promise for better rates of neurologically intact survival?

I`ll be waiting for these changes to come in on the next review of the UK guidelines. It sort of makes the continued discussion of ET tubes or LMA for cardiac arrest a little redundant though!!

Do you have any thoughts on this?

Advertisements

Responses

  1. I like it! Gonna tread on some paramedic toes though with the ET issue …

  2. Interesting. We have been doing this for a number of years now and are the only service in the UK to be doing so. And it works too! We’ve never experienced so many ROSC before.
    My services version is called Protocol C.
    As well as what you have already kindly posted here are a few extra’s that I know.
    Remember the days when we shocked fine VF? Not any more. Chest compressions only to coarsen it up! The heart in VF is quivering so it is still filling with blood but not pumping anywhere, therefore the heart becomes engourged with blood. At some point the heart will become so full of blood when we shocked nothing would happen, usually straight into asystole. If we shock a heart so engourged with blood it isn’t able to contract, it’s like shocking a solid lump. By compressing the chest we are emptying the heart. After a couple of minutes of this we then shock and hey presto the heart is able to contract again. Also with an engourged heart; when the heart is like this and then we start ventilating we just make things worse by building up intrathoracic pressure making it even harfer for the heart to contract. I’ve also heard that our cells can actually retain O2 for up to 15 minutes therefore making ventilations not that important in the initial stages of resus.
    We do 100 compressions, check rhythm, 100, shock, 100, check and 100 shock we will then add a breath every 6 seconds during the 4th set of 100 compressions whilst continuous CPR. We can get a tube and IV straight away (it’s up to us) as long as Chest compressions aren’t interupted and we don’t ventilate (use a positube). During the check rhythm we keep hands over centre of the chest and don’t take any longer than 5 secs to do this and as soon as a shock is delivered we are back on the chest rapidly. I think our service are in the process of collating data to put before the resus council. There are a lot more people walking around thanks to this new type of CPR/CCR.
    http://www.secamb.nhs.uk/latest-news/july-december-2006/december-2006/south-east-coast-ambulance-service-recognised-for-excellence

    I hope what I’ve posted makes sense, I’ve just been away and it’s late.
    Cheers

  3. I’m only a student paramedic in Australia, but I do remember learning a little bit about this over the last couple of years, in line with the change to resus guidelines that were brought about over here. Whilst obviously the care of the patient is the most important factor, it does make me a little sad that in some areas there is a move towards the deskilling of paramedics, eg no intubation in resus. I wonder how far this “deskilling” will go?

  4. I dont think its about the deskilling of paramedics… simply that evidence suggests that this new protocol will improve patient outcomes.

    My only question is, surely using an OP airway will not protect the patient if they vomit and then aspirate. Is there not still a need for atleast an LMA/combitube to provide some form of protection? When the patient starts to vomit, this is a little too late to try and secure the airway dont you think?

  5. Thank you – I think this aspect of your blog is brill! It makes the brain work on retrieving the info from that physiology degree all those years ago.

  6. Very good article and, especially with Mac’s help, I finally understand the rationale behind it.

    Thank you

  7. I found this really interesting and it takes things one step on from what I recently learned on my EMT foundation course. Our tutors were very hot on emphasising the importance of compressions before shocks and getting straight back onto it after. And also the relative non-importance of ventilation in comparison. I don’t know where you’d find it online but there’s a very good video of the effects of a VF arrest on a pigs heart, in terms of how it becomes engorged and also how compression can reverse this.

  8. This is a very interesting concept and does make perfect sense. We have started to utilize the Res-Q-Pod in our service and this is a step forward with regards to resusitation. I would like to see higher emphasis on chest compressions but there is too much precedent on ALS skills. IV cannualtion, intubation etc. I have seen too many providers stop compressions for long periods while they try with the difficult airway, or one time i saw a crew do no compressions on a patient for approx 1-2 mins while they set up their autopulse machine ( which perfoms chest compressions mechanically). I read of a study in regards to resusitation with BLS and ALS services and the BLS saw a higher ROSC than the ALS services due to high quality chest compressions with no time wasted on ALS interventions. However I dont think that the airway should be completely neglected due to the high incidence of aspiration and a simple non rebreather or OPA will not suffice. We use the King airway which replaced our combitubes and they can be placed with ease and with no interuption to chest compressions.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Categories

%d bloggers like this: