Episode 9 - The rEVOLUTION of ECMO

What are the indications for ECMO beyond ARDS and refractory cardiogenic shock? In which patients should we consider eCPR and is this the new standard of care for patients sustaining out-of-hospital cardiac arrest? Finally, how do I work towards safely and efficiently weaning my patient from VV or VA ECMO? 

These are just a few of the questions that we address on Rounds with our guest faculty member and Director of the UCLA Adult ECMO Program, Dr. Peyman Benharash. In this comprehensive review of ECMO we also explore the regionalization of ECMO care here in Los Angeles County, as well as the day-to-day considerations that you want to bear in mind when assessing and caring for your patients requiring extracorporeal life support.

Learning Objectives
By the end of rounds you should be able to:

1. Understand the indications & contraindications to VV and VA ECMO support

2. Describe the basic components of an ECMO circuit

3. Describe the role of eCPR in the management of adult patients with out-of-hospital cardiac arrest

4. Discuss key management strategies to safely wean patients from ECMO

5. Describe common complications of ECMO and strategies to mitigate them

Take Home Points

• ECMO is time-sensitive, therefore, early and safe cannulation is an important determinant of outcome
• ECMO is a bridge to therapy
• Use of scoring systems like the Murray Score may be useful to stratify the severity of ARDS among patients being considered for VV ECMO support
• The indications for ECMO are expanding to include technically challenging operative cases
• eCPR is a promising therapy for patients presenting to an ECMO center of excellence with refractory VF/VT cardiac arrest 
• ECMO therapy, particularly VA ECMO, may affect virtually organ system
• The potential role of ECMO therapy during the current COVID-19 pandemic remains to be defined

Time Stamps

• 00:12 Introduction
• 01:16 Overview of Rounds 
• 02:13 The rise of ECMO 
• 02:46 CESAR & EOLIA trials summarized 
• 05:40 Venovenous (VV) vs. Venoarterial (VA) ECMO
• 08:24 How to decide whether or not to place a patient on VA ECMO?   
• 10:33 Timing & indications for ECMO support
• 11:38 Murray Score explained
• 12:24 Contraindications & patient selection for VV & VA ECMO
• 13:56 Expanding indications for ECMO
• 15:23 ECMO in the Setting of Trauma: Pneumonectomy & Retrohepatic IVC injuries
• 17:45 Regionalization of ECMO in Los Angeles County
• 21:52 Who should be cannulating?
• 23:22 Approach to cannulation
• 24:50 Distal perfusion catheters for VA ECMO
• 26:10 Differences between VV & VA ECMO
• 28:24 The W5H of eCPR
• 34:26 Considerations for access for VV ECMO
• 35:53 Avalon catheter 
• 37:51 VV versus VA ECMO circuits/set-up explained
• 43:30 Getting your patient off of ECMO & other key considerations
• 48:56 Vasopressor & inotropic therapy during VA ECMO
• 50:31 Virchow’s triad,  antithrombotic therapy & bleeding on ECMO
• 54:30 AKI, end-organ dysfunction & the daily assessment of patients on ECMO
• 57:22 ECMO 2.0 & the role of evolving technologies
• 61:20 Role of ECMO during the COVID-19 pandemic 
• 66:45 Take-home points
• 68:38 Outro

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Transcript

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SPEAKER_00 0:01

From the classroom to the emergency room, OR and beyond. You're joining Trauma ICU Rounds with your host, Dr. Dennis Kim.

SPEAKER_01 0:12

I feel that a lot of our patients could be saved, even postoperative patients when they're in shock or trauma patients can be saved by ECMO. We just have to do more of it, get better at it, do it early with less anticoagulation, and do it before irreversible and organ function has set in.

SPEAKER_00 0:31

That's Dr. Payman Benaroch, a cardiothoracic surgeon and associate professor in residence of surgery and bioengineering at UCLA.

unknown 0:38

Dr.

SPEAKER_00 0:38

Benaroch is an award-winning educator and prolific researcher whose cardiac outcomes research lab, better known as the Core Lab, is actively involved in health services research, the development of non-invasive physiologic sensors, as well as the design of physics-based models for virtual surgery. Regarding clinical interests, Payman has an active practice that ranges from traditional cardiac surgeries to minimally invasive, hybrid, and catheter-based therapies for heart disease.

SPEAKER_01 1:06

Additionally, one of the main focuses of my practice is in fact extracorporeal circulation as it relates to respiratory failure as well as cardiopulmonant failure.

SPEAKER_00 1:17

I recently had an opportunity to sit down with Dr. Benaroche and discuss a variety of key issues related to ECMO, ranging from ECPR or extracorporeal CPR, to expanding indications for ECMO beyond the more commonly accepted reasons, such as acute refractory hypoxemia in the setting of ARDS. We also had the opportunity to discuss Dr. Benaroche's efforts and early experiences with the regionalization of ECMO care here in Los Angeles County. As the director of the UCLA Adult ECMO program, Payman has been instrumental in getting the division of trauma here at Harbor UCLA up to speed with regards to our ECMO program, and we've had several great successes over the past few years with VV ECMO support for patients with ARDS from a host of traumatic and non-traumatic etiologies. Before we get into all of that, let's begin with first things first, the rise of ECMO from an experimental procedure in the 1970s to a modern-day staple of organ support therapy in specialized centers across the world.

SPEAKER_01 2:14

What has happened over time is that ECMO has become more mainstream. As you may know, ECMO was initially developed in the 1970s, and it never really took off until the late 2000s when the H1N1 pandemic came. At that time, two critical things happened. One was the pandemic and the large volume of patients who had respiratory failure that required ECMO. And number two, a trial called the CSER trial came out demonstrating the benefits of EC1 respiratory failure.

SPEAKER_00 2:46

And for those listeners unfamiliar with the results of the CSER trial, which was published in the Lancet in 2009, this is a highly cited prospective five-year RCT in 180 adult patients in the UK with severe but potentially reversible respiratory failure who are randomized within seven days to undergo either conventional management or referral for consideration of ECMO at a specialty hospital. Patients were considered for inclusion if they had severe respiratory failure with the Murray score greater than or equal to three, and we'll talk about the Murray score in just a little bit. And this was an intention to treat analysis with the primary outcome being death or severe disability at six months. Interestingly, of the 90 patients referred for ECMA, only 75% actually received ECMO. And regarding the main outcome measure, 63% of patients allocated to the ECMO arm survived to six months without disability, versus 47% of those in the conventional management arm. So that's an absolute risk reduction of 16%. Study investigators also found that in settings with similar services to those in the UK, this strategy might also be cost effective. Now, like every trial, there were some methodologic issues which may have potentially limited the conclusions that could be drawn from the study, and a more recent and also highly cited 2018 trial, the ECMO to rescue lung injury and severe ARDS, also known as the Eolea trial, was published in the New England Journal of Medicine in an effort to provide further clarity regarding the role of VV ECMO in adult patients with severe ARDS. In this study, which was stopped early for futility, 249 patients were randomized to VV ECMO or conventional ARDS net management, including the use of proning, neuromuscular blockade, and other adjuncts PRN, there was no statistically significant difference in the main outcome measure, 60-day mortality, which was 35% in the ECMO group and 46% in the control group. However, secondary outcomes favored the early VV ECMO group, including a lower relative risk of treatment failure, defined as death or crossover to the ECMO group, lower number of days prone, lower rates of renal failure, lower rates of cardiac failure. Interestingly, over a quarter of patients in the control group who ultimately required ECMO required VA ECMO due to cardiovascular collapse. I think the key take-home here is that modern ECMO is safe and is not associated with significantly higher mortality than standard care. And when used as a rescue modality, ideally early, ECMO can help improve survival in patients who might otherwise die. So please do check out our show notes at traumaicrounds.ca or traumaicurounds.com, where you can find links to the studies discussed as well as other great ECMO resources. So, Payment, having discussed some of the relevant ECMO literature for pulmonary support, let's discuss the modes or types of ECMO and how they differ from, say, traditional cardiopulmonary bypass.

SPEAKER_01 5:41

ECMO, as you said, is extracorporeal membrane oxygenation. In its original form, it was meant to exchange venous blood, take the venous blood out, add oxygen, take out the CO2, and return it back to the venous system. This would only supplant the function of the lungs. So it would still, the blood would still go through the heart and the lungs themselves. And therefore, it's not a form of bypass. However, another use of ECMO is for cardiopulmonary support. And in the venoarterial mode, as it's known, the blood is removed from the venous side and returned to the arterial side as pressurized and oxygenated blood. And this would in fact be very similar to what you mentioned, cardiopulmonary bypass, because if you run ECMO at full support, all the preload is now removed into the ECMO machine, and therefore the heart is beating, but it's empty. And so that is, in fact, you could have a heart that stopped, and that's very similar to what we do in the operating room. Now, even in the veno arterial form, ECMO is different than cardiopulmonary bypass, and there's nuances to it, including the fact that ECMO is a closed system. In the operating room, most systems are an open system. In other words, there is a reservoir that blood pours into, and that reservoir is open to air. It turns out the air-blood interface is very inflammatory. So it can cause a lot of inflammation, which then produces fibrinolysis, infection, SIRS, and so you can't really stay on traditional cardiopulmonary bypass for too long before bad things happen. However, with ECMO, it's a closed circuit and there is no reservoir. Because there is no reservoir, there's no air interface, you can stay on these circuits for a long time with much less inflammation.

SPEAKER_00 7:48

So when I think about VV ECMO, it really seems fairly straightforward and is akin to dialysis for the lungs. When you're assessing a patient for ECMO support, however, it seems that many patients will be on vasopressors or some sort of vasopressor support, perhaps in part due to myocardial suppression in the setting of sepsis or RV dysfunction due to the increased afterload resulting from hypoxemic phasoconstriction. And so my question for you is how do you make the determination regarding whether or not a patient requires circulatory support or VA ECMO as opposed to simple pulmonary support in the form of VV ECMO?

SPEAKER_01 8:24

The accurate determination of what you're asking is in fact very difficult, and it depends on center expertise, but also provider expertise and each patient. I'll tell you what we do, and that's just one way to do it. And let's say a patient has ARDS from sepsis. We always, nearly always, check their myocardial function using an echo. Because it turns out myocardial uh depression from sepsis and shock is something that's underappreciated. And we typically, if you're on more than moderate dose pressors, in other words, epinephrine or epinephrine dopamine, sometimes you use the vasoactive another score of the VIS. But oftentimes, just clinically, we can look at a patient. If they are oliguric, they have evidence of Norgan malprofusion like elevated liver enzymes, lactate is up. We are much more interested in VA eCMO. But if they don't show any signs of Norgan dysfunction, even though they're on some pressers, just let's say it's from paralysis and heavy sedation, and they're on low dose Epi or NorePI or vaso, then we would tend to use VV. The advantage of veno venous ECMO is that it's uh fairly simple. The cannulas these days are put in percutaneously using a Seldinger method as opposed to the open traditional cutdown.

SPEAKER_00 9:48

And for patients who are undergoing VA ECMO, where exactly are the distal tips of these catheters sitting?

SPEAKER_01 9:54

Usually in the very proximal iliac, common iliac, or in a very short patient in the distal aorta.

SPEAKER_00 10:03

And so then how does that returning oxygenated blood return to the brain or say the upper extremities?

SPEAKER_01 10:08

Yeah. Retrograde perfusion. If you have no head pressure coming from your aortic roots, basically the femoral artery is higher pressure, so everything blows backwards. And this causes a problem in patients who have a lot of atheromatous disease, for example, because now they're getting their whole aorta sandblasted and a lot of debris from below can go to the head and cause strokes.

SPEAKER_00 10:34

Definitely not an outcome we want to see. And we're certainly going to talk about some of the complications of V V and VA ECMO. But before we get there, is it pretty much safe to assume that sooner is better in terms of getting patients on ECMO? And what are the major indications for initiation of ECMO support?

SPEAKER_01 10:50

One of the reasons we do ECMO early on is to prevent the lung injury that comes with mechanical ventilation with high airway pressures. And so to reduce the barotrauma early using ECMO can really change the course, I think, of ARDS and make it be a very brief period rather than late. Of course, this is a debatable strategy. And in our center, we are very comfortable with V no Venus ECMO, and therefore our recommendations are to consider it if the PAO2 to FIO2 ratio, known as a P2F ratio, is less than 100. So it's less than 100, I think the discussion should be had because it takes time to mobilize the teams. And certainly less than 80, I think that the patient should is a candidate to go on.

SPEAKER_00 11:39

So earlier you had mentioned the Viz score. The other score that gets talked about quite a bit and that our listeners might want to be familiar with is the Murray score. And this score, just like you were explaining, incorporates the P to F ratio in addition to three other variables that are assigned a weighted score that helps us stratify the severity of ARDS and potential candidacy for ECMO placement. And those variables include compliance as well as PEEP or positive end expiratory pressure, and findings on the chest x-ray, specifically the severity and quantity of infiltrates based on quadrants of the lung. Now, provided that the patient has the indications for ECMO, can you talk to us a little bit about some of the contraindications to extracorporeal life support?

SPEAKER_01 12:25

I think it's very important, much like any surgical specialty that you have, to know the contraindications. Well, it's a lot easier, I think, to put people on than to say no. And I think it's the no part that takes a lot of judgment. With regards to our strategy on how to select patients, the patients who are ideal candidates for veno venous ECMO are patients who really have single organ dysfunction, and that is their lungs. They ideally are not on dialysis, they have good systemic perfusion, they don't have any hematologic issues, they don't have any malignancy, and the cause of their lung injury is reversible, such as a pneumonia, aspiration, drowning, things like that. Even if you don't do calculations in your head, you just gotta look at a patient and say, is this reversible in the short several days that ECMO can provide? And if it's not reversible, what is the outlet? For example, somebody who has pulmonary fibrosis and needs to get a lung transplant, it's very important before you put them on to have a bailout strategy, to have an out as opposed to just having to turn off the machine in several days. And this comes to the ethical issues of ECMO, where families and patients alike are going to be subjected to some very difficult decisions. And we, as the folks who are going to initiate it, it's incumbent upon us to make sure that we have discussed all these issues and thought about them in detail before jumping into ECMO.

SPEAKER_00 13:57

So recently it seems that the conditions or indications for ECMO are expanding beyond ARDS and refractory cardiogenic shock to a host of other conditions. Several months back, we had a patient together who was found down intoxicated in a ditch with a GCS of 111, no evidence of a head bleed, and this is when I was still taking call up at Regan and Westwood. His core body temperature was, I think, 26 degrees Celsius, and we were able to put that patient on the circuit in the trauma bay, rewarm him, and he was discharged within 48 hours, neurologically intact. That brings me to the next question. What are the expanding indications or scenarios where we should be placing patients on ECMO? One particular scenario where we've had or seen its effectiveness is in status asmaticus, for example.

SPEAKER_01 14:41

Asthma exacerbation is a sort of the perfect prototype for someone who will do well on ECMO for a very short period of time, things that are reversible. We also do a fair amount of ECMO nowadays, venous ECMO for periprocedural support. For example, let's say a patient has a tumor of the carina or airway where they can't be ventilated or oxygenated. Instead of struggling to put armor tubes in and doing creative ways to ventilate the patient with jet ventilation, we're able to put cannulas in the groins, for example, and be able to provide adequate oxygen delivery and CO2 removal while the patient has no ventilation at all.

SPEAKER_00 15:24

So as you just heard, there really does seem to be an expanding role for ECMO. And I know that at some trauma centers, for example, at shock trauma in Baltimore, Maryland, they've incorporated V V ECMO into their operative management strategy for patients undergoing, say, uh a pneumonectomy in the setting of life-threatening thoracic trauma. And I definitely want to refer our listeners to a great East Trauma cast with Dr. Dave Zonis and Jay Mennecker, hosted by the one knownly Matt Martin, going over some fundamental basics of ECMO and trauma or for the acute care surgeon back in 2017. Now, the other injury where V V ECMO is being advocated for is retrohepatic vena cava injuries. In my career date, these patients uniformly die. And we've deployed atrial caval shunts early in the operative course of management of these injuries. And in my experience with an NF4, the mortality rate has been 100%. Thoughts or considerations for the use of ECMO in patients with retrohepatic cava injuries?

SPEAKER_01 16:19

Yeah, I think we had one such injury. Unfortunately, the patient did not survive. But I think in cases of massive trauma like that, it's my preference to go through the chest directly. And so you have you can cut the diaphragm and have access to this area. Number one. Number two is that ECMO not having a reservoir is very sensitive to air getting entrained into it. So if air comes in through the venous side, which is on suction, air will get directly to the other side and get pumped back into the patient. And so you can end up with an air embolism on the arterial or the venous side, both of which are fatal. So in these cases, an actual bypass machine, which has a reservoir, so the air does not get trapped, air can come up. That is, I think, a far more helpful way to do it. I think one of the things for trauma centers to consider is to institute early just veno arterial bypass. So drain out of the venous system and return the blood back into the arterial side using bypass. There's not a whole lot of downsides to it. Also, the bypass machine allows you to rapidly scavenge blood using the pump suckers. So you don't have to be cell-saving and doing all sorts of things. So I think this has to be tried. I have no real experience outside of one. And I think that more and more studies are needed to find whether or not this is feasible or not.

SPEAKER_00 17:45

And so while we're on the topic of trauma and trauma centers, one of the foundations of successful trauma care delivery is regionalization of care and development of trauma systems. Much has been written regarding the importance of centralizing care and developing centers of expertise or ECMO specialty centers. And in fact, the CSER trial was a great example of this. Any thoughts on how we're doing with regards to regionalizing our extracorporeal life support services?

SPEAKER_01 18:11

I don't think ECMO is nearly as regionalized as it should be, or nearly as organized as the trauma systems are. However, it turns out we are in far better shape than we were even five years ago. We were facing a problem where we couldn't transport patients across the county of Los Angeles to our hospital because they were too sick or too hypoxemic and hypotensive. Ultimately, what we decided to do is to use the model that has been previously performed in Columbia and University of Maryland where we can go retrieve patients. And obviously, there are centers around the world in Australia and France and Sweden that have been doing these retrievals, but it was new to us. What we decided to do is to get a core group of people together, surgeons and nurses, respiratory therapists, and profusionists, and go to select places within our reach to go put patients on ECMO, stabilize them, and then bring them here.

SPEAKER_00 19:13

And so let's say that I'm at a community hospital here in Los Angeles County and I've maxed out therapy. How exactly do centers or healthcare providers reach out to have a patient considered for ECMO? And what does this process look like?

SPEAKER_01 19:28

So as I mentioned to you, we have a number available that's our transfer center's number, but also uh through personal contacts with me or any of the other members of the ECMO team, our intensivists, our pulmonologists get calls from area and pay from folks around the area. And ultimately, we discuss the patient. And after I look at the stuff, I sometimes have my cardiologist or pulmonologist also talk to the referring physician. Once we have all the information available, we have a group call. These are all happening very quickly. And the group call, everything from nursing considerations to transport to destination, ethical issues are all discussed to make sure that we know what we're getting into, and that's really the right thing for the patient to be getting ECMO at this time. If that's all okay and everybody agrees, then we activate the team, and the team is our ambulance, a respiratory therapist, two EMTs, a critical care transport nurse, a profusionist, myself, and usually an assistant, a surgical assistant, which can be a resident, another attending.

SPEAKER_00 20:39

And so that's a fairly large team. Is the transport all via ground or are you using air transport as well?

SPEAKER_01 20:46

Yes, we are doing ground transport, and actually they have demonstrated that without use of fancy helicopters within LA County and even 120 mile radius, we're able to get to patients fast enough. And uh, you know, to carry such a size team across uh with a helicopter, I think can be kind of a daunting task. But also the other thing I have learned as we're writing up our experience with ECMO is that we're actually doing things very simply and at the bedside. A lot of retrieval teams take the patient to the operating room at the index institution and doing it there. And that transport can be treacherous. We're doing these at the bedside. And so it takes some coordination for equipment between us and the hospital that's sending us the patient. We need to use often their surgical equipment, but at the bedside to do this.

SPEAKER_00 21:38

And is this being done in the emergency room, ICU or OR?

SPEAKER_01 21:42

We have done it in the emergency room, in the ICU, in the operating room in their operating room, if the patient, for example, was having heart surgery and can't come off. So we've done it in a variety of settings.

SPEAKER_00 21:52

So regarding cannulation, is this something that's being done predominantly by surgeons and should the subspecialty matter? The reason I ask. Is that with another catheter-based therapy for unstable bleeding trauma patients, Reboa, there's been a lot of debate regarding who should be performing this procedure and how to credential personnel. What are your thoughts regarding who should be cannulating and initiating patients on ECMO?

SPEAKER_01 22:16

Yeah, this is obviously a hot topic, and there are lots of ways to do safe cannulation. The key, I think, cannulation is safety. And uh where I trained, the adage was don't do something unless you can fix this complication. That goes for peripheral cannulation, where you know, if there is a problem with the femoral artery, I should be able to fix it. And I think it doesn't necessarily matter who should be doing it as far as a specialty, but whoever is doing it should be highly experienced to minimize complications. We have seen that same volume outcome relationship within our own group, where it turns out all cardiac surgeons can do ECMO, but very few do now because they know that there are these ECMO specialists around. So I would say it's less specialty driven, but really based on whether or not you can fix the problem. If there is a problem, for example, if you can't get it in the groin, are you able to go into the chest and do it somewhere else? And secondly, is the number of cases you do.

SPEAKER_00 23:22

Regarding approach, are you using an open or cut down approach, or are these all being done predominantly via a percutaneous approach?

SPEAKER_01 23:29

Nowadays, with the presence of very thin walled cannulas and the prevalence of the Seldinger technique and how comfortable surgeons are, the Seldinger method is the most commonly used method to candidate patients for ECMO. So this, much like a central line, although it's much bigger, includes accessing the vessel and using a wire to get in and then serially dilating to the appropriate size. And basically the large candula goes over this wire. Now, in our experience, because a candula is so much larger than a typical central line or a cortis catheter, we like to exchange the wire for a stiff wire so that it doesn't bend. Any of you have done enough central lines, you know that every once in a while when you put in that central line, the wire comes out kinked. And that's probably what predisposes back walling of the vessels and a tear. So in order to prevent that from happening, we exchange the wire to a stiff wire once with a small dilator.

SPEAKER_00 24:26

Yeah, and I think that's a key point here. It's very important to maneuver that wire back and forth as you're inserting your dilator over that wire, because if it becomes trapped, kinked, or bent, that will predispose towards backwalling the vessel or otherwise unintentional injuries. And given the large size of these cannules, that can potentially be fatal in patients who are undergoing cannulation for ECMO.

SPEAKER_01 24:51

Once the cannulation is performed, if in a vino arterial site, we secure the cannulus completely with interrupted sutures, and then we make a separate cutdown below the cannulation site on the arterial side to access the superficial femoral artery. And then we put a purse string around it, and then again through the middle of the purse string, we poke the vessel, we put a fine wire distally, and then we use a variety of distal perfusion catheters. What we're currently using in our practice is actually a single lumen cordice. It works out well, it's cheap, and also comes in a wire reinforced model that can prevent kinking, which we used to see with the regular soft ones.

SPEAKER_00 25:32

And so is it safe to say that all patients undergoing VA ECMO are having a distal perfusion catheter place?

SPEAKER_01 25:38

When we have looked at our own experience over the many years, since we began routine use of distal perfusion catheters, we have really significantly reduced the amount of limb ischemia. I think a lot of centers, including some of the Asian centers, use distal perfusion catheters regularly. On the other hand, places like University of Michigan are far less likely to use preemptive distal perfusion catheters, and they first wait for signs of limb ischemia before they embark on this.

SPEAKER_00 26:10

So we talked earlier about some of the indications for VV versus VA ECMO. Dr. Benrosh, can you explain to our listeners some of the intricacies and major differences between VA versus VV ECMO? And what's the latest and greatest regarding ECPR?

SPEAKER_01 26:27

Absolutely. Happy to. I'll start with veno arterial ECMO first. Veno arterial ECMO, as I said, drains the blood from the venous side, pressurizes it, and oxygenates it, and then returns it back to the arterial side. So it's in its, once it's running in full form, it's a modality to support the function of the heart and the lung. So that patient, if you're on full ECMO, will have no pulsatility on their arterial line. There'll be no pulse, but they'll be alive. And this is due to the fact that their pressurization of all the vascular trees is coming from a non-pulsatile source. Now, there are many differences between veno arterial and veno venous ECMO. And I'll go into some of them within the limits of the podcast. But with veno venous ECMO, essentially the flows are adjusted to achieve an adequate arterial oxygen levels and CO2 levels for pH. On the other hand, with veno arterial, it's not only the oxygenation that matters, it's also the cardiac output. So the patient needs to have an overall cardiac index of about 2.5 at least, 2.4 to 2.5, with their own native ejection, what's coming through the heart, and a and the supply from the ECMO circuit. So now you're talking for a 70 kilogram adult, you're talking about a minimum of 5 liters of flow. If you don't supply that and you use pressures to get the pressure up, what you'll end up with is a patient who's in cardiogenic shock because in fact there's inadequate liters per minute of blood and oxygen delivery to their end organs. So for veno arterial echo, it's very important to pay attention to the total flow to make sure that it meets the minimum standards of cardiac index. And if they are not making urine or their liver enzymes are going up, you have to wonder if you're truly providing adequate flow to the patient. As far as ECPR, ECPR is a far newer modality where patients who are receiving CPR and chest compressions are going on ECMO. And this has been done now many times around the country and also internationally. There's a very famous picture of surgeons putting a patient who had a cardiac arrest at the Louvre Museum in Paris. And that was really cool to see. Patients in refractory arrhythmias like V fib that don't come out, this is really their only way to survive. And so what you do is under CPR, you have to be able to candidate the artery and the vein, and you put them on veno arterial ECMO. Once you get perfusion established, you obviously don't need any more CPR because now the patient is getting perfused. And oftentimes the heart, because it's now empty and it's being pressurized through the coronaries, it'll defibrillate. And that's our experience is that once you go on ECMO, it'll defibrillate, and then they go to the cardiac catheterization lab to figure out if there was a coronary problem or something else that may have caused the fibrillatory event. So ECPR is sort of the currently the ultimate way of providing ECMO because it has to be done quickly. You're in time constraints, you know, you have 15, 20 minutes to do it, and but it's very rewarding because about 30 or 40 percent of these patients in some centers survive. The issue of ECPR is again a very hot topic because it may be the new way to resuscitate patients. However, it does require a lot of collaboration and pre-hospital assessment in particular. So there is a movement in LA County, at least I should say before COVID came, because right now everything is on hold, to have patients as part of trials who are in refractory VT or VF, who have witnessed arrests, who, as far as they can tell, are otherwise in decent shape. Those patients will be brought to a ECMO center rather than the nearest STEMI center. And um if this happens and a trial shows benefit, I think this could become part of the standard. But currently it's under investigation. Some places are doing it regularly. If a patient ends up coming to UCLA in cardiac arrest, we need to quickly decide what we're going to do. So currently we have established internal guidelines because as you can imagine, if every cardiac arrest ends up going on ECMO, you end up with several things very poor results, high resource use, exposure of staff to undue risk. And so for these reasons, usually centers that do ECPR have guidelines. Also, as you alluded to, the type of arrest is very important. A PEA or asystole, we are far less likely to put them on. Fibrillation, more likely. And of course, the downtime from arrest, actual arrest, to going on ECMO is a very critical number in the neurologic outcomes of these patients. So we try to really make sure that the patient gets transported to UCLA definitely within 30 minutes.

SPEAKER_00 31:41

And so once these patients are placed on ECPR, are you actively cooling them or using ECPR as a means of providing some form of hypothermic therapy post-rest?

SPEAKER_01 31:52

That's yet another debated topic. You know, uh there was a surgeon in Canada named Bigelow who would dunk animals in ice-cold Canadian lakes and operate on them with no pulse, and then they would wake up and the animal would be fine. And so he's sort of the father of hypothermia. So nearly all surgeons, cardiac surgeons, I should say, subscribe to hypothermia. As a modality, we do it regularly when we do heart surgery to protect the organs, because as you know, with cooling, your metabolic rate goes down, therefore oxygen consumption goes down. And with ECPR, there are several trials that have been done with hypothermia as they have with regular cardiac arrest without CPR. And the results have been mixed. As you know, every few years the evidence changes. We currently do cool patients. Once again, even though we went through a period of just making sure they don't get uh febrile. Now we're cooling patients, and of course, ECMO is the perfect way to cool patients from within inside. So we can cool them to usually 32 degrees to 34 degrees. The key issue with ECPR is neurologic recovery. We can get almost all the other organs back, but the brain, once it gets reperfused, it develops swelling and reperfusion injury. And so one of the next steps in getting ECMO to become more successful would be mitigation of neurologic injury.

SPEAKER_00 33:19

And so, Payman, I can imagine that cannulation of these patients must be somewhat technically difficult if they're undergoing active CPR in the emergency room. How does that all work out?

SPEAKER_01 33:30

So during CPR, it's uh very challenging. So usually at our facility, we have two people working in either groin, looking for femoral access. With ultrasound access and good ultrasound access, we're able to visualize the vessels often, but sometimes it has to be blind based on anatomic landmarks. So halfway between the pubic symphysis and the ASIS, that's where we think the femoral artery is, and so we go medial to that to find the vein, and then we move laterally to find the artery. But ultrasound has been very helpful in these cases, and oftentimes it's hard to tell what's arterial and what's venous, so that takes a lot of judgment. In ECPR cases, I don't think we'll be able to do neck cannulation, for example, except for neonates. And um, there's specialized pediatric cardiac teams that do neonatal ECPR with actually remarkable success with cutdowns.

SPEAKER_00 34:26

And so I understand that you're doing this percutaneously for the most part. In terms of the actual access and sites, is there a standardized approach? And where are your go-to sites for cannulation in the setting of ECPR?

SPEAKER_01 34:39

Yeah, that's highly variable. My go-to site is two femorals. As you can imagine, if you put two cannulas in either femoral vein and one is sucking the blood, draining it out of the patient, the other one is returning it at the same level. If the tips of the cannula are very close to each other, you get something called recirculation. You're basically draining the same blood that you just gave back to the patient. So the cannulas have to be offset. So when we do femoral vein to femoral and femoral vein access for veno venous, one cannula is pushed far in near the atrium, and the other one is in the lower IVC. So we usually have to have them offset by at least 15 centimeters, if not longer. Now, the traditional way veno venous ECMO was done and is still done at many centers currently, is to use uh femoral vein to jugular vein. And there the cannulas are by definition very far away from each other. We don't really use neck cannulation as a primary site because often these have been accessed before. It's also not expeditious to have two sites prepped in case of an emergency to go in. But certainly we have done it before. It's just not our go-to site.

SPEAKER_00 35:54

And so Payman, some centers are advocating for use of the Avalon catheter, which is a dual lumen catheter that typically sits in the IJ and can both drain and then return blood through a single catheter. Is that something that you would consider putting in immediately, or is this more of something that should be put in for patients who will require ECMO on a more long-term basis?

SPEAKER_01 36:17

Yeah, great question. So the Avalon catheter, just for our listeners, is a dual lumen catheter. So it's one tube, but it has a very thin film membrane, and so half of it is used to drain blood, and the other half is used to return blood. Now, how do you avoid mixing, which is something I discussed earlier? With the avalan catheter, there is side hole, so the return is actually directed in one direction in the middle of the cannula at the tricuspid valve. So instead of going back into the IVC or the SVC, it goes across the tricuspid. And so that reduces mixing. The avalanche, it turns out, is somewhat hard to manipulate once it goes in, and you need transesophageal echo and fluoroscopy or fluoroscopy to do this. And so in emergency situations, the avalon is certainly not recommended. The avalon, as you alluded to, is something that's in the neck, and so patients can be ambulatory, maybe extubated and walking, and it's more for longer-term use. Personally, I do not recommend an avalon as the first choice for ECMO unless the patient is stable. For example, in patients who require ECMO as a bridge to transplantation, but they're not actively crashing. I think an avalan catheter can be put in under circumstances that are more stable. It requires TEE. Even though we do it at the bedside at UCLA, a lot of centers transfer them to a fluoroscopy suite with TE. So the patient has to be stable for all of that.

SPEAKER_00 37:51

So we've talked quite a bit about the indications for ECMO as well as regionalization of extracorporeal life support here in Los Angeles County and the evolving role of ECPR. Maybe let's take a couple of steps back and just to think about the differences between VV and VA ECMO. If I'm a house staff who now has a patient that's been placed on ECMO, what are the sort of day-to-day considerations that we want to take into account when we're rounding and assessing our patients at the bedside?

SPEAKER_01 38:23

With veno venous ECMO, which is what we're going to start with, the circuit remains on the venous side. It drains from the venous side, the blood goes through a cannula, goes to a tube, and then goes into a pump. Now, the pump in most circuits that are used nowadays is a centrifugal pump. So it's a blade that's spinning at about 3,000 to 5,000 RPMs, and it sucks blood from the middle using the centripetal force and it ejects it in a pressurized fashion through the side. And once it gets pressurized, then it goes through a some kind of a membrane, and that's known as the oxygenator. And the membrane is a semi-permeable membrane that's gas permeable, but not to blood or plasma proteins. And on the other side of the blood, it's like what your lungs have, there is air on the other side, and gas passes through the side. That gas in common vernacular is known as sweep gas. And so the more sweep gas you have going across, the more CO2 you'll remove. And also the composition of the sweep gas can be adjusted using a blender. So you could go from an FIO2O1 all the way down to 21%. So based on the sweep gas, you can kind of adjust the parameters of oxygenation and ventilation. Now, once the blood gets passed through this membrane, it ends up going to another tube, which is now returning the blood back into the patient through another cannula. So the things you look for in veno venous ECMO is really how many liters of flow you have, how many liters of blood flow you have, how much sweep gas you have going, and also on a regular basis, we check the circuit for clots. This also is true for veno arterial ECMO. There's fibrin strands that can form, and so we need to adjust our anticoagulation, or in extreme cases, exchange the entire circuit or parts of the circuit to prevent the fibrin or the clots from traveling into the patient. Now on the venoarterial ECMO, it's a similar setup with regards to a drainage cannula, a pump, which is centripetal, and also a membrane, but then on the other side it ends up going into an artery instead of the vein. So there it's far more important to make sure that there is no air or debris going into the patient, and that basically increases the stakes of having fibrous strands on the membrane side that's closest to the arterial. And so the perfusionist or ECMO specialists regularly check these with flashlights very carefully to make sure there's no fibrinous strands forming, and we can adjust anticoagulation or exchange parts of the circuit. Now, with veno venous ECMO, let's say you're waiting for lung recovery and you want to see what the patient's lungs can do. Well, it turns out you can turn off the sweep gas altogether. And all what's happening is that the venous blood comes out and goes right back in. So it doesn't really affect the patient's oxygenation very much when the sweep is closed. However, veno arterial ECMO, if you turn off the sweep gas, then the blood that's going into the arterial side now all of a sudden is dark. And so that if let's say you're on partial ECMO and your head is being perfused with your native circulation through your lungs, then all of a sudden your lower body, which is receiving the deoxygenated ECMO flow, could be in serious trouble. So we never turn off the sweep gas on venoarterial ECMO. We do turn down the actual blood flow on venoarterial ECMO to see what the heart can do on its own. And so that we do regularly is known as a weaning trial to get the patients off ECMO as soon as feasible. Let me say something else about venoarterial ECMO. So in a patient who has native ejection and the heart is beating and pumping blood, and you're candidated from the femoral artery, and let's say you have partial ECMO flow going, you can develop something that's known as north-south syndrome or horliquin syndrome. And what this is, is that the part of the body that's receiving ECMO blood could be very oxygenated, and that's typically the lower extremities. And the upper extremities that are getting, including your brain, that's getting native blood, could be very desaturated. So Horliquin syndrome is very important to pay attention to because you can get differential oxygenation of the body from top to bottom. So a postoximeter or a blood gas drawn in the lower extremity may be inaccurate and show you a very high PO2, whereas your brain may be starved. So in cases of horliquin that cannot be overcome with increasing the ECMO flow, we have to transition to yet another type of ECMO, which is known as VAV vein to drain, and giving some of it to the arterial circuit, but also giving some of it back to the venous circuit. So it's a combination of venoarterial and veno venous ECMO. That allows not only support of the circulation, but also some oxygen being added to the venous side so that the upper extremity is also being saturated.

SPEAKER_00 43:31

So obviously, ECMO is not without risk. And I would imagine that similar to a patient who's on the mechanical ventilator, every day we're going to be thinking about how we can liberate that patient from the vent. With regards to ECMO, what are the sort of considerations that we want to take into account to know that our patients are getting better and maybe are ready to be weaned off of the circuit?

SPEAKER_01 43:54

Good question. Obviously, one of our goals is to get the patient off ECMO because ECMO, as wonderful as it seems, It also has a lot of complications. So one of the things, let's talk about the veno venous case first, is to try to get the patient off ECMO and on the ventilator, or even better than that, to get them extubated. So it depends on your goals. If you're talking about a patient who has a chronic lung problem that's awaiting a lung transplant, these patients are often not going to come off ECMO until they get transplanted. So our goal there will be to mobilize them, whether it's through lower extremity cannot or switching them to an upper extremity method where they can walk. Because it turns out mobility is one of the key aspects of getting a lung transplant and surviving it and doing well long term. So our patients often, once they get go on ECMO, they get trached. And after that, they're able to be liberated from being in bed and they get walking and getting physical therapy until they're listed for transplant. Now, in a case of ARDS where transplant is not the end goal, we're trying to get them off the ventilator. So while they're on the machine, while they're on ECMO, we try to minimize ventilator settings. So open lung ventilation with moderate doses of PEEP, 10, 12, 15, and not a lot of total volume to prevent barotrauma. And obviously all the CO2 is being removed by the circuit. So all we're trying to do is to keep the lungs open to get some gas exchange and get the oxygen level up. But really, ventilation is not a key issue. And as you assess the patient, you look at their lung compliance every day, chest x-ray, physical examination, these patients often need some diuresis. And once that's all accomplished, what you can do is you can turn down the sweep gas, which is the amount of air that's going on the other side of the membrane, and watch their oxygen level and CO2 level in their arterial blood. And you can also uptitrate the ventilator settings slowly by increasing the total volume, the rate, and eventually you'll be at a point where the sweep can be off all the patient has adequate oxygenation on the arterial side. Then you know the patient is ready to come off ECMO. On the veno arterial side, which is for again lung and heart support, it's slightly more complicated than that because not only do your lungs have to be ready, your heart has to be ready also. And so in order to do the testing the heart, you usually have a swan gangst catheter placed in these patients where you can look at the native cardiac output as well as their pulmonary artery pressures and CVP and the preload. You also do nearly daily echocardiograms to see how the heart is doing and recovering. And you're looking for recruitment of the muscle, ejection fraction, but also things like valvular regurgitation, which can be important. One of the things that can happen during the venoarterial ECMO course is that because there is no blood really going into the heart, the heart, if it's not moving, it can develop blood clots. So one of the things we did not discuss is strategies to vent the left ventricle. Because if you don't vent it and the ventricle is distended and dilated, a few things happen. Number one is that clots can form from a stagnation. Number two is that because the intramural pressure is so high, the blood flow from the coronary doesn't actually make it to into the myocardium. And so the patient can continue to have myocardial ischemia. So it's very important to prevent this tension of the left ventricle. And there are many strategies for that. One of the most common ways to do it these days is to put an impella device in. An impella is a percutaneous axial pump that is used to as a ventricular resist device typically, but it can also be used to go across the aortic valve to left the left ventricle. There's ways to create an atrial septostomy and to drain the pressurized left atrial blood into the right atrium. There's also ways to stick a cannula, small cannula, into the apex of the left ventricle through a mini cutdown, although that's less commonly used. But there is ways to vent the left ventricle. So back to weaning, we need to make sure the ventricle does not get distended. There's no clots in it. And that with adequate ionotropic support, which is often required in these patients, the patient can sustain a normal map, mean arterial pressure, but also an adequate cardiac index with the ECMO blood flow this time being turned down. So we do these tests almost every day and we turn down the ECMO flow, we see how the arterial pressure holds up. If, for example, you turn down the ECMO flow and the mean arterial pressure goes from 70 to 50, you know you're not ready. On the other hand, if it maintains around 65 to 70, you know that whatever the ECMO machine is not pumping, your heart is pumping. And therefore, you can now look at it more carefully with an echocardiogram and appropriate inotropes to see if you can come off.

SPEAKER_00 48:58

And on the topic of vasopressors and inotropic support, Dr. Benarosh, is there a particular preference for one type of vasopressor or inodilator versus another? And I'd imagine the majority of patients who are receiving VA echimal support are going to be on some form of vasopressor therapy.

SPEAKER_01 49:17

Yeah, great question again. Yeah, all of them require some sort of inotropic support. The reason is that even if the myocardium is not necessarily dead, it's stunned. So you need to bring some of that contractility back with pharmacological means. And of course, you don't want to come off on rocket fuel because then that leads to other end organ dysfunction. But if you're on sometimes they require low to moderate dose pressors to come off. And the way we assess that is again looking at the cardiac index, looking at urine output-based deficits with the ECMO flow turned down. And of course, when you turn the ECMO flow down, you risk having blood clots forming in the ECMO circuit. So at that, during the brief times that we're doing this, we're adding extra anticoagulation. The choice of inotrope really depends on the hemodynamics of the patient. If you have a very hypertensive patient that requires it, of course, milrenone is a good choice. However, patients on ECMO typically are also vasodilated because of the low-grade inflammation that's going on. So epinephrine is our go-to, but really any combination of milrenone, vasopressin, milrenon, and norepinephrine, dobutamine, milrenone, any of these can be used. It's theater's choice.

SPEAKER_00 50:32

And so while we're on the topic of pharmacotherapy, obviously, in addition to the risk of bleeding, patients are also at risk for clots, thrombosis, as well as embolisms. So how do you balance that? And what are some of the strategies that you're currently using to decrease the risk for clots in these patients?

SPEAKER_01 50:52

Well, great question. This has to do with uh Verkaus triad, stasis, hypercoagulability, and endothelial injury. And unfortunately for the ECMO circuit, there is no endothelium. So one is out already. And so now you're talking about how anticoagulated the patient is and how much flow you have going. And so if you're running the impeller at low RPMs and you have, you know, let's say a liter or two liters of flow, you're much more likely to have areas of stasis within that oxygenator and that circuit. So there you need to increase the anticoagulation and keep the time period where this is happening at low flows to a minimum, minutes. However, the whole circuit is basically hypothetically thrombogenic because it's not endothelial coded. Now, newer circuits they have these biosurfaces, as they call them, and they come in a whole different set of varieties. Some used to be heparin bonded, now there is heparin-like molecules that reduce the inflammation and hypothetically coagulation. Whether or not it works or not is unclear. However, most circuits are in fact coated with something at the present time. I don't think any of the coatings are really perfect, but they can be used with varied success. Now, anticoagulation is itself a big question. What cardiac surgeons have been using for years is what we use in the operating room, and is that known as the activated clotting time ACT. However, it turns out ACT can be highly variable and it's not a good measure of how anticoagulated the blood is, which has been really shocking to the cardiac community. So a lot of um ECMO centers are using uh 10A levels, heparin concentrations, and PTTs to judge how much they want to anticoagulate patients. I'll tell you that we are still in the uh phases of using ACT, and so our experience mostly is with ACT, so we're looking for an ACT of about 200 seconds for safe when we feel good about it. Now, sometimes the patients are bleeding and we have to hold anticoagulation altogether or give them factors, including sometimes factor seven in the cases of postcardiac surgery on ECMO, which can be uh very nerve-wracking. However, you can have a bleeding patient on ECMO, and we have to stop the bleeding somehow. And interestingly enough, the risk of thrombosis and uh strokes and thrombabolic events over the years in general has gone down, which means that whatever we're doing, whether it's a circuit or management of flow, is getting better to a point where clots are a lot less uh likely to happen.

SPEAKER_00 53:45

And regarding choice of anticoagulation, is your go-to anticoagulant going to be heparin? And what about the potential utility of newer novel anticoagulants such as bival, for example?

SPEAKER_01 53:58

Yeah, absolutely. I think they people around the world use these. Heprin is the easiest because it's we are familiar with it, first of all. Second of all, it's fast on, fast off. However, in cases where the patient develops heparin-induced thrombocytopenia, we immediately switch to argatroban. But bivalve is certainly an option. We don't have any experience with bivalve here, but argatroban and heparin are certainly the two that are used. I would say about 80% of our patients at one time are getting heparin.

SPEAKER_00 54:31

So in addition to clots and thrombosis and the need for anticoagulation, I can imagine that many of our patients are going to be at risk for a whole host of other complications. Specifically, I'm thinking about the incidence of renal failure or AKI or the development of a cardiorenal syndrome among patients, particularly those who are placed on VA ECMO. Can you comment and tell us a little bit more about some of the things we should be looking for on a daily basis when we're thinking about organ systems outside of just the heart and lungs?

SPEAKER_01 55:05

It's true. We used to think that ECMO causes patients to go into renal failure by providing non-posatile flow. It turns out that's not exactly the case. It's not the ECMO that's doing it, but it's the process that led to ECMO and the use of pressors and things like that to maintain blood pressure. So I would say that about 40% of our patients or so require renal replacement therapy on ECMO. Fortunately, it's temporary and it comes back, and with adequate perfusion from the ECMO circuit and lowering the inotropes and vasoconstrictors, the kidneys often come back, even a couple months after this is all over. ECMO affects nearly all organs. ECMO can affect the brain, as we discussed, so it's important to assess neurologically because patients can not only have ischemic strokes, they can also bleed into their heads. And if they're sedated and paralyzed, you have no idea what's going on. So it's very important to reduce the amount of sedation patients are on and assess them neurologically very quickly because if a subdural develops, for example, you can catch it before it's devastating. Hematologically, it can cause fibrinolysis, so fibrin levels can be low, it can bleed, platelets can be consumed, similarly leading to bleeding. The liver can see problems, including hyperperfusion, and you get uh elevation of parenchymal enzymes. Hyperbilirubinemia is something that happens from hemolysis, but also liver dysfunction separately. And if it's from liver dysfunction, it turns out it can be a very poor prognosticator for long term. So patients with elevated bilirubins, for example, are often not candidates for advanced therapies like VAT or transplant because these patients often die of end-stage liver disease ultimately. Intestinal tract, uh, ECMO can again lead to ileas or sometimes ischemic bowel. Actually, a lot of times ischemic bowel, but again, that's not from the ECMO, it's from the pressors that are used to support the pressure. So it's really important to be judicious about how many pressors and how much of each one uses. And abdominal exams are very important. Leg ischemia or limb ischemia, we discussed, really it can affect every organ.

SPEAKER_00 57:23

So at last year's SCCM annual meeting, Dr. Ron Bartlett was given the Lifetime Achievement Award for the fantastic groundbreaking work he's done on ECMO since the 70s. One of the things that he did discuss was this whole notion of ECMO 2.0, where we don't actually need to have a perfusionist at the bedside around the clock and we're getting patients up and mobilizing early. Any thoughts on this?

SPEAKER_01 57:48

Yeah, these are issues that are now coming up with advanced technology, but also a relative uh lack of perfusionists for the demand of ECMO. At our center, we still continue to use profusionists because I strongly feel that these folks are really the highest qualified uh people to take care of a circuit, and in case of a failure, they can exchange the pump very quickly. I don't think that really anyone else, including myself, would be able to exchange a pump expeditiously enough to save a patient. And so I really worry about that. On the other hand, out of necessity and uh sometimes economics, one has to change the ECMO model to be driven by what they call ECMO specialists, nurse specialists, etc., etc. And those are all possibilities which have been tried with various success. There are some centers that use, for example, just a bedside nurse to do this with great outcomes. On the other hand, we don't feel comfortable with that. But of course, one of the variables that affects this is the issue of technology and how complicated are these circuits really. The ECMO circuit during Dr. Bartlett's time used to take up an entire room, and there is very interesting pictures of it online. However, the newest generation of these circuits are about 15 pounds that can be carried on to a jet fighter to be carried around the world. And there's a balance you have to strike between how small and self-contained things are versus how much you want to know about the circuit. Some of the very self-contained ones, you really cannot see the inside. They just have two tubes coming out. And everything is regulated with regards to pump speed to ensure a certain flow. My personal philosophy is that in institutions like where you work and where I work, training institutions, it's very important for the trainees and everyone else to see really what's under the hood, so to speak, and be able to troubleshoot this device rather than a screen telling you what to do. So we still use sort of the older generation. However, that does not mean that our patients don't walk around. In fact, we have some of the highest ambulatory rates of any center, especially in patients who are awaiting a transplant. So I think you have to decouple walking from technology. The technology, there's some really fancy devices out there with high costs, you know, things that cost, you know, per patient, you know, five to ten times as much. And because ECMO is going to become somewhat of a uh an increasing market in the near future, we have to be cognizant of its costs. And ECMO hospitalization costs a lot. And we have a very finite amount of uh funds we can spend at a national level on our patients. So we have to be stewards of costs to make sure number one, patients with a high chance of recovery go on ECMO, and two, that we preserve, we reduce the amount of money we're spending on equipment in order to make it more available for more people. So my tact is currently to use the sort of the cheaper generation stuff that are highly reliable, that which is the test of time, they're cheaper and more widely available rather than going to the fancy devices with servos and things like that.

SPEAKER_00 1:01:21

Now, given the current pandemic, I guess we'd be remiss to not at least discuss a little bit about the potential indications and role for ECMO in patients with COVID-19 and severe ARDS. When I review the literature and look at studies coming out of Wuhan and Washington as well as New York, there really doesn't seem to be a huge demand, or at least there hasn't been a significant number of patients who have gone on to require ECMO. Any thoughts or ideas regarding ECMO during the current global pandemic?

SPEAKER_01 1:01:57

I think the topic of COVID is an unfortunate one and something that we really don't know a whole lot about at the present time. The center experiences across the nation, but also internationally, are highly varied. We have an organization called ELSO, Extracorporeal Life Support Organization, which now has a dashboard, a daily dashboard, and is collecting data on COVID patients. And also it's reporting their outcomes in real time rather than traditionally waiting three months to see what happens because there's such a need for good quality data. We have been on several international calls through our societies where folks, especially uh very successful stories out of France in Paris, they have done over 100 patients, over, in fact, 200 patients, and have had very good outcomes. But even in their own experience of a regional group of hospitals that have been doing this, the uh success rate is highly variable between uh you know 10% uh survival to 40% survival, which is on par with most viral illnesses. Their thought is that ECMO will be a very useful therapy, but much like what Dr. Bartett experienced early on, if you put them on early, on ECMO early, they survive. But of course, you could be criticized because some would say that these patients would have survived regardless of ECMO. And so I don't think we have enough data yet, but it is far more encouraging now than it was early on. Some of the experiences from Asia initially were pretty dismal. So we have very strict guidelines. Again, the patient has to be very young, no other organ dysfunction, and be neurologically intact. But also we're recommending all the adjunct therapies first, like proning, like paralysis, plus minus nitric oxide, before we jump to ECMO. But the French experience and some of the colleagues in New York, they're having a good experience putting the patients on early. So this may in fact become one of those things where putting them on early can save the patients, and it's going to be the story of uh standard ARDS repeated all over again. It's just that currently we have no real good data, and I suspect that in the next couple of months, uh, once the uh smoke clears, we're going to know a lot more about this disease and the role of ECMA.

SPEAKER_00 1:04:24

Yeah, it seems like every day there's a new study being released that's providing us with a little bit more of an insight into the pathophysiology, optimal management strategies and such for COVID-19. Now, most of these cannulations you're doing right at the patient's bedside. So, given the current pandemic, what sort of strategies have you and your team discussed in terms of performing ECMOcannulation uh safely without undue risk to the healthcare providers? Are these being done in a negative pressure isolation room, or are you still planning on doing these at the bedside, for example, in the ICU versus the operating room?

SPEAKER_01 1:05:07

You know, I have to tell you that we've been fortunate on the West Coast to have had very few of these cases thus far. But from our limited experience, we're not doing them in negative pressure rooms. The patients are kept in the same ICU bed and they're unproned briefly. The whole issue is a logistical issue with ensuring that the healthcare providers do not get exposed during this process, which can come to sometimes be hectic. So, first of all, an experienced candidator should be doing this, or two candidat should be doing this together. The setup is that you have to have a almost like a full bodysuit, like these uh white Tyvek suits that you see, and and a Papper or an N95 mask. And then you over that you wear your sterile stuff, and you have to have your trays and things like that all ready to go on the outside and just. Wheel them in. There should be time and size should be minimized. You have to have an orchestrated uh plan and a team that knows exactly what's going to happen at every stage. So I hope that we can practice this once this pandemic is over more with the group members before we do this again. Because I think there's a lot of things that are unknown to us. I personally had never done it under the circumstances before with two suits, you know, wearing two suits and the masks that are uncomfortable and anxiety levels certainly that cannot be underemphasized. But I think with team training and the more we know about this disease is going to uh sort of alleviate some of our anxiety and make us perform better.

SPEAKER_00 1:06:46

Absolutely. So listen, Dr. Banarosh, I want to take this opportunity to thank you so much for sharing your experience and knowledge with us and the listeners and for joining us on rounds. Uh, before we sign off, are there any key take-home points or clinical pearls that you want our listeners to take with them to the bedside in the care and management of patients on ECMO?

SPEAKER_01 1:07:08

Yeah, first of all, I want to congratulate you, Dr. Kim, for having this amazing podcast. I listened to the one on respiratory failure, and I thought it was pretty amazing and actually very informative. And I think this is a new way to learn all the principles that we used to learn in a whole different setting. And so congratulations for that, and thank you very much for having me. With regards to what listeners should take away, is that think about ECMO early and think about it often in patients who are having refractory illnesses like refractory hypoxemia, refractory hypotension. I feel that a lot of our patients could be saved, even postoperative patients when they're in shock or trauma patients, can be saved by ECMO. We just have to do more of it, get better at it, do it early with less anticoagulation, and do it before irreversible and organ function has set in. So I think that the next decade will bring us a lot more clarity. I think that patients who, let's say they get a Whipple and they have SERS and they're hypotensive, instead of turning on all depressors, if they have a good outlook on as far as survival is concerned, we should be putting them on ECMO early, maybe use low anticoagulation. And unless we do things like this, we're not going to have enough data points to figure out what to do in the future. But I think ECMO should be considered early for refractory hypoxemia, cardiogenic shock.

SPEAKER_00 1:08:39

And that concludes our rounds for today. I want to thank you so much for joining us on rounds. If you like what you're hearing and you feel like it's making some sort of a difference in your clinical decision making and day-to-day care of patients, please do subscribe to us at Apple iTunes, Stitcher, Spotify, or wherever you're downloading your podcast from. Please do leave us a positive comment as well as a rating. And do visit the website at www.tramaicrounds.ca or dot com and check out the show notes as well as the references for today's episodes. Until next time, stay safe, keep reading. We'll talk soon.