Out of Hospital ECLS (Extracorporeal Life Support)

[mycrofft]

Next thing: field dialysis for poisoning.

There has to be a limit between field and hospital measures. That said, then the original goal of field EMS, stabilization and transport, reappears.
How about more hospitals with better distribution? Shorter run times.

 

[Veneficus]

That's a strong assumption to say that people (me) were degrading medics. The circumstances that you pointed out are the reason I rather not have a medic, nor a nurse or resident do it.

Sorry, just the way I read it.

As we know sometimes inflection and intent is lost in the written word.

 

[mycrofft]

Who else can thread that artery like that.....

embalmers!

 

[Veneficus]

embalmers!

I am sure with instruction and practice anyone could threat the veins, but those machines are not "fire and forget" devices.

 

[medicdan]

I'm curious (and naive), could ECMO or other bypass forms be used to maintain organ perfusion while waiting for organ transplant? Could we foreseeably see training specialty teams to "procure" in the field-- or at least begin bypass and transport (non-emergent) to a transplant center? These would be cases with clear brain death but healthy organs.

 

[Brandon O]

I'm curious (and naive), could ECMO or other bypass forms be used to maintain organ perfusion while waiting for organ transplant? Could we foreseeably see training specialty teams to "procure" in the field-- or at least begin bypass and transport (non-emergent) to a transplant center? These would be cases with clear brain death but healthy organs.

http://www.eurekalert.org/pub_releases/2010-12/nlmc-mba113010.php

 

[ECMODoc]

ECMO for transplant

EMTDan,

"I'm curious (and naive), could ECMO or other bypass forms be used to maintain organ perfusion while waiting for organ transplant? Could we foreseeably see training specialty teams to "procure" in the field-- or at least begin bypass and transport (non-emergent) to a transplant center? These would be cases with clear brain death but healthy organs."

Yes. It's been done for the donors, and it's called EISOR (extracorporeal interval support for organ retrieval) and is used for non-heart beating donors. It's not widely used but hopefully it will catch on.

http://www.thoracicsurgerynews.com/...Issues/Thoracic-Surgery-News-Nov-Dec 2008.pdf

The problem with using ECMO for indefinite lengths of time are the complications often related to the needed anticoagulation.

I happened upon this topic because I get Google alerts for the term "extracorporeal life support". I'm not an EMT so I hope I'm not intruding. I'm a physician and have had extensive training with ECMO. I'd be happy to add any info I can to the conversation.

 

[ECMODoc]

Very interesting discussion. It's really nice to see people thinking out of the box.

But there are a few problems with "out of hospital ECMO".

1. This really goes back to the argument of stay and play or scoop and run.

2. Cannulating with a 17-23Fr cannula is a surgical procedure, it's not just a big IV, and carries significant risk. Tearing the femoral artery isn't something you want to do in the field.

The papers quoted were interesting. But in Germany, like much of Europe physicians can and often go out on runs. I suppose they could theoretically cannulate in the field, but placing large cannula without good light, instruments, and a good sterile field is not something I would want to do.

By the way, someone mentioned earlier that ECMO generally ended up with poor outcomes in adults. Not so. For adult respiratory failure survival is upwards of 60% (and probably greater when using Veno-venous ECMO exclusively at an experienced high volume center) and many of these patients had P:F ratios of less than 100 and were failing mechanical ventilation--without treatment survival would probably be 20-30%. Usually, with VV ECMO a 21-23Fr drainage cannula is placed via the right femoral vein with the tip in the hepatic IVC, and a short "arterial" 17-19Fr infusion cannula via the right internal jugular vein.

I've seen ECMO-CPR work for cardiac failure, but this was an IN-Hospital arrest in the cardiac ICU. I can't tell you the survival statistics off-hand. Veno-arterial ECMO is used for cardiac arrest.

Also I would have to classify transport ECMO as different than out of hospital ECMO, as cannulating at an outside hospital with all of the equipment, light, etc. is quite a different undertaking than trying to do it in the back of an ambulance (next to impossible), or living room floor, or sidewalk. And remember it requires blood, significant amount of anticoagulation and most of all surgical expertise...especially if something goes wrong.

 

[RocketMedic]

The training required to use this would literally shift some of the US medical system's best cardiac surgeons onto ambulances. I think that although the concept is worth exploring, we should focus on basics first.


Pie in the sky, but what about some sort of ultrasonic clotbuster for the heart?

 

[Brandon O]

Doctor,

Thanks for the input.

Can't get at them now (on my phone), but the 2010 AHA guidelines have a lit review on in-hospital ECMO for arrest. Some success as I recall but limited in scale.

If you had carte blanche to conceive the most feasible way possible to get someone onto artifical circulatory support in an austere environment (with or without oxygenation), what would it be?

 

[usafmedic45]

If you had carte blanche to conceive the most feasible way possible to get someone onto artifical circulatory support in an austere environment (with or without oxygenation), what would it be?

Not bother doing it? There's no better option exists than a vascular cutdown. It's not something American-style paramedics have any real business doing.

 

[usafmedic45]

The training required to use this would literally shift some of the US medical system's best cardiac surgeons onto ambulances.

It doesn't take a cardiac surgeon to do this sort of thing. Remember that most ECMO teams operate with non-surgeons (CCM or EM docs) and the non-insertion aspects are largely done by RTs or RNs with special training.

Pie in the sky, but what about some sort of ultrasonic clotbuster for the heart?

I riddle you this: What happens when you bust up clots? Even on the coronary level, remember that busting up the clot is simply going to kick it further downstream so you will likely still wind up with ischemia but just in a more distributed pattern. The risk of breaking up the atherosclerotic plaques might increase occlusion rather than clearing it.

Also, the question of the right impulse aimed at the right thing at the right time is going to be a huge technical problem. Speaking as an echocardiographer, trying to aim for something as small as a coronary artery even under ideal conditions is going to be difficult as best. I'm not sure that an impulse designed to break up objects is something that should be broadly applied to the chest in the hopes of clearing a clot.

 

[systemet]

Also I would have to classify transport ECMO as different than out of hospital ECMO, as cannulating at an outside hospital with all of the equipment, light, etc. is quite a different undertaking than trying to do it in the back of an ambulance (next to impossible), or living room floor, or sidewalk. And remember it requires blood, significant amount of anticoagulation and most of all surgical expertise...especially if something goes wrong.

Thanks again for posting on this thread. It's rare that we have someone with your sort of expertise contribute to these discussions.

I understand that this sort of intervention may not be possible in the field without involving specialty physicians, in which case the cost-benefit analysis starts skewing rapidly towards cost. But I would like to point out that the potential for benefit in a prehospital population with absolutely dismal baseline outcomes (compared to inhospital arrests), might be quite large.

In the face of a large benefit, more risk might be acceptable. I wonder if it might be possible to perform this in a less technical manner than done in-hospital, accepting that this is not the optimal manner in which to do the procedure, but have this outweighed by a potential benefit?

As a paramedic, it seems like we have been told many times over the years that certain things aren't feasible in the field, because of technical requirements for their use in hospital, e.g. only an anesthesiologist should perform RSI, or we need a cardiologist/EM physician to administer thrombolysis, only to find out that these inteventions can be carried out in a n acceptable manner (in some systems, with good physician oversight), in a relatively austere environment.

The alternative for this population of patients seems to be a survival rate of < 10%. I wonder how much we would have to change this sort of number to make it worthwhile?

 

[RocketMedic]

You have to temember that our arrest stats are biased against us by the fact that we are perpetually starting "behind the 8 ball". Arrests in hospital, if detected, can summon a full code team quickly and treatment ASAP. We have to get to the scene first.

I understand my clotbuster is far fetched, but could it work?

 

[usafmedic45]

I understand my clotbuster is far fetched, but could it work?

Several major technical issues:
1. Hitting the "target". Working with ultrasound isn't as easy as a lot of people think it is.
2. Finding the right frequency to bust up clots without damaging tissues or atherosclerotic plaques. Sound waves that are able to "bust things up" tend not to propagate well out of a handheld transducer and tend to have some rather prominent effects on surrounding tissues. Ask anyone who has been through extracorporeal shockwave lithotripsy (such as myself) for kidney stones. My concern is that a similar effect could result (if focused on the heart) in cardiac contusion or other similar injuries that would reduce the chance of successful resuscitation.
3. Not all coronary events are thrombotic (clot-induced) in nature.
4. What happens if your patient had previously been in atrial fibrillation prior to arrest and in getting the probe positioned to "bust the clot" in the coronary artery, you pass over the atria (remember that the circumflex runs right under the atria) and bust up that clot. If the patient gets ROSC, then you've just increased that patient's risk of an embolic event (read as: stroke) several fold.

It's an idea that sounds plausible in theory but I'm willing to bet it wouldn't work (transthoracically at least) in a practical manner. I believe it has been tried through cardiac catheterization before though. A PubMed search would bring up any relevant research.

 

[Veneficus]

As a paramedic, it seems like we have been told many times over the years that certain things aren't feasible in the field, because of technical requirements for their use in hospital, e.g. only an anesthesiologist should perform RSI, or we need a cardiologist/EM physician to administer thrombolysis, only to find out that these inteventions can be carried out in a n acceptable manner (in some systems, with good physician oversight), in a relatively austere environment.

It has been my experience that it is not the technical requirements of treatment that are often the main inhibitor, but the technical requirements to incorperate treatments in a given system.

During my career 12 leads and cpap were at once considered unfeasible. During that same period we were being trained on the administration of blood products and were stocking the ambulance with blood tubing. Despite the educational investment, ultimately the plan was cancelled due to the logistics of properly maintaining the paperwork and the blood.

 

[systemet]

I understand my clotbuster is far fetched, but could it work?

I'm not sure that the technology exists to do what you're suggesting. I did find a description of the use of a special ultrasound catheter in combination with thrombolysis in pulmonary embolus treatment, here: http://www.medscape.com/viewarticle/750903

However, this requires angiography, and the risk associated with distal embolisation is probably less in PE (source: my own uneducated opinion, and a wild-assed guess).

Intraarrest thrombolysis using TNK has been studied though, without success here:

http://www.ncbi.nlm.nih.gov/pubmed/19092151
http://www.ncbi.nlm.nih.gov/pubmed/12015391

(The second study is particularly awesome, because it was done, partially, by paramedics in 1998.)

 

[usafmedic45]

However, this requires angiography, and the risk associated with distal embolisation is probably less in PE

It is, since the lungs are more or less designed to serve as big clot filters. Even if you further "embolize the emboli", they are just going to spread out through the pulmonary circulation. This is not necessarily a bad thing either....

 

[systemet]

During my career 12 leads and cpap were at once considered unfeasible. During that same period we were being trained on the administration of blood products and were stocking the ambulance with blood tubing. Despite the educational investment, ultimately the plan was cancelled due to the logistics of properly maintaining the paperwork and the blood.

Wow, your service must have been seeing a ridiculous amount of trauma to even consider that.

 

[ECMODoc]

Thanks for having me, I appreciate you all not minding the intrusion.

"If you had carte blanche to conceive the most feasible way possible to get someone onto artificial circulatory support in an austere environment (with or without oxygenation), what would it be?"

You know, honestly I think I'd have to agree with USAFmedic, and not bother doing it. It takes considerable time to place two cannula for Veno-arterial ECMO properly even under good conditions and it helps if the patient is already in an ICU environment (entering a larger artery on full anticoagulation should make anyone pause).

No it doesn't necessarily take a cardiac surgeon to cannulate (I know pediatric, general, vascular, and trauma surgeons who do), but again fracturing a large vessel and the amount of bleeding that could occur--and remember the patient is fully anticoagulated isn't something a non-surgeon would want to or have the ability to deal with especially not in an austere environment. However, cannulating in Forward Resuscitative Surgical Suite or forward deployed military hospital would be acceptable. Again the equipment is available to deal with a surgical intervention if necessary.

It's interesting that the military has become very interested in ECMO for severe acute respiratory failure lately. And there have been some technical advances that are making ECMO more attractive like the CardioHelp http://www.youtube.com/watch?v=ozWZ1iNAMWc and

The Avalon Bi-caval DLC http://avalonlabs.com/animation/animation.html (this one DEFINITELY requires placement by an experienced surgeon in an OR under fluoroscopy--trust me, don't let anyone tell you different).

The great thing about these two is that the first makes moving a patient much easier, the second gets the cannula out of the groin and allows for early mobilization. There are places that walk their patients on ECMO, and alot of places are keeping their patients lightly sedated or even awake.

BTW USAFmedic, I don't know anyone who uses cut down in adults for ECMO, it's all percutaneous. I've only rarely had to use ultrasound to get the needle in (morbidly obese patient or odd anatomy). You are also correct that most ECMO teams aren't run by surgeons (where I trained it was, and I think this worked well for reasons I won't go into). The key to ECMO isn't inserting the cannula but the critical care over the next few days to weeks.