Thank you so much for having me today. So I wanted to talk about the prevention of RV failure, in particular for those patients who are on ECMO. As was mentioned, I did work in Dr. Bartlett's lab. I work right now at the University of Pennsylvania, and we're a very large ECMO program. We do about 225 to 250 ECMO patients a year, and I help triage, cannulate, and manage patients with respiratory and cardiac failure. I have no conflict of interest. So my learning objectives are to discuss the management of RV failure prior to the institution of ECMO, to identify factors that can lead to RV failure while on ECMO, and then prevention of RV failure while you're on ECMO, once you get there, and then ways to mitigate that for the duration of your ECMO support. So when you have a patient prior to going on ECMO, you need to strategize mechanisms to mitigate RV failure. So what are the tools that you have? We just discussed ECHO and using those scores, like the PAPI score and TAP-C and S-prime. In addition, some of these patients may have a PAC or a SWAN in, but there are two other factors that you can look at. One is the VIS, which is the vasoactive infusion score. So for those patients who are having progressive RV failure, you can calculate, based on their epinephrine and norepinephrine and phenylephrine dosages, if you're requiring escalating amount of pressors, that they potentially may have RV failure going on, as well as using the vent settings as a surrogate marker of dysfunction in being imposed onto the RV. Then the next thing you have to determine is what the ideology of the RV failure is prior to going on ECMO. Do you have somebody who's in straightforward ARDS, or are you dealing with somebody who is in ILD, or do you have somebody who has pulmonary arterial hypertension? Those are all different entities, and it's important to tackle and identify the ideology of RV failure. The general principles of pre-ECMO RV support is RV support, regardless of you going on ECMO or not. That includes fluid optimization, making sure that the RV preload is optimized either by diuresis or loading. Typically, the RV is not a load ventricle, but making sure that whatever curve the RV needs to be on is correct, trying to maintain systemic perfusion, which therefore is the mean arterial pressure, as well as supporting the perfusion of the coronary system, making sure that the RV afterload is not too high, using pulmonary vasodilators, inhaled nitric. In Canada, if you have infusion, milrinone, those sort of options, as well as inhaled milrinone, and then trying to mitigate the external pressures by modifying the ventilator as much as possible. At the time of cannulating, you may see a patient, as we just learned on echo. This is a TE image. I'm cardiac anesthesia, so I use TE primarily. You can see the RV here bulging into the left ventricle. Then also looking at the SWAN numbers, here you can see a patient that has near systemic PA pressures with a mean delta from the mean pulmonary artery to systemic mean pressure of maybe 16 here, and a rising CVP with a TR waveform on the CVP here. Once you are instituting or potentially instituting VV ECMO, you have to understand how you're going to mitigate the RV failure if you go on ECMO. The question really becomes, can you use ECMO prior to the development of RV failure? This is like in a prophylactic setting. I'll talk about using VV ECMO as a rescue from RV failure, but there is some concept now that we are starting to develop, us as a group here who do a lot of ECMO management, is can we use right ventricular assist support or ECMO support to protect the kidneys prior to developing AKI from those patients who are going on to RV failure? Can we use ECMO and RV support to wake these patients up as they're coughing and sucking down and having increased amount of sedation requirements? Can we use RV support, mechanical support, to decrease the wall tension, to rest the RV before you develop RV ischemia and failure? Can you use VV ECMO and RVAD for patients prior to them developing PA dilatation? We know there was a study done that for those patients who had a PAC before and after ECMO, they noticed that the PA pressures go down when you go on ECMO, VV ECMO, when their CVP tends to normalize. Their cardiac output and index gets better as their RV sort of becomes more in tune with the left ventricle. So currently at the University of Pennsylvania, we have a prospective study where we're actually looking at comparing VV ECMO versus RVAD prophylactically as a non-inferiority for RV protection. So this is in that question that was asked. Can you prophylactically guard from RV failure? We know that VV ECMO can help with RV failure. And how does that occur? The first question is, why not choose VA ECMO? Well, we know that VV ECMO, like I just said, improves the CVP, the cardiac output, RV function. But also, once you put someone on VV ECMO, you improve the hypoxemia and the hypoxia. And then subsequently, the PA pressures improve. That's from the hypoxic pulmonary vasoconstriction, as well as improves the hypercarbia, corrects some acidosis, improves with cardiac contractility, as well as the PA pressures. We know that when you go on VV ECMO, you decrease the mechanical ventilatory forces. But that's really in particular to those patients who are in ARDS, who are on extreme mechanical ventilator settings. We also have subpopulations of patients that are not intubated, maybe breathing fast, or they have pulmonary arterial hypertension and hypoxic, and maybe they're not on the ventilator. So those in that subpopulation of patients who have ARDS may benefit with VV ECMO to protect the RV. So generally, the recommendation is if you have somebody with impending RV failure or maybe heading in that direction with rising creatinine and LFTs, perhaps you should start with VV ECMO. And then you can reverse them or switch them to VA ECMO. Although technically, if you are in frank RV failure with cardiogenic shock, you should maybe even consider VA ECMO. So once you go on ECMO, there are some small causes or some causes of progressive RV failure. And that needs to be investigated as well. That could be because there's underlying ILD, underlying pulmonary arterial hypertension. Not a dynamic pulmonary hypertension, but a fixed pulmonary hypertension. So in my mind, you have patients who have dynamic inducible pulmonary hypertension, those who you're trying to wake up or have a hypoxia that you're reversing. But then there's a fixed component, maybe those patients who had already pulmonary arterial hypertension going into prior to going on ECMO. So while on ECMO, if you have continuing rising doses of pressors, maybe a small microthrombotic disease that's coming off the tip of the cannula, or maybe someone who has COVID, for example, may have progressive RV failure. So you have to watch for those things while you're on ECMO. There's multiple different cannulation options, which some of the other guys will get into and we can talk about in the discussion section. But you know, VV ECMO is one option for maybe prophylaxis or protecting the RV. I don't like to say protecting because it's an invasive tool to use, but VA ECMO also offloads the RV. But now we have advanced tools like the Oxy Arvad using like a right IJ impella. It's not oxygenated, but it's a new device. We can come from the IJ or the groin. Potentially those patients who have RV failure and you put them on VV ECMO and they have some element of LV failure, you could use a balloon pump. Or we encounter patients that have a balloon pump existing and they are hypoxic and are having RV failure, you can put them on VV ECMO. The balloon pump itself doesn't exactly help the RV, but what it does is help the LV, which therefore helps the RV. And then another option is using VV ECMO with an ASD if you have refractory pulmonary arterial hypertension. And these are some of those images. This is us putting a catheter across the interatrial septum via an arterial ECMO. This is Oxy Arvad and traditional VV ECMO. This is one of the options we can use for patients who are having impending RV failure. And now at the University of Pennsylvania and what a lot of the groups around the country are doing, particularly with COVID, is doing upfront Oxy Arvads. And in these situations, you know that you can prevent or sort of mitigate the risk factors or the consequences or sequelae of RV failure. And then like I mentioned, transeptal techniques, including VV ECMO plus shunting across interatrial septum. And then there's obvious limitations with ECMO that we all know about, but VV in particular is a series circuit. It doesn't actually directly provide ventricular cardiac support. And then those patients who are on VV ECMO who are attempting wake up, they're coughing, they're sucking down, having hypoxia, recirculation, we're not there 24 hours a day. They're developing RV failure as they go. And we've seen some of these patients who have been on ECMO for months that they start developing RVH and RV failure. And so those patients, you may need to use other strategies, mechanical support strategies, in addition to the medications for RV support. So I can talk about this topic ad nauseum.

RV failure prevention

Extracorporeal Membrane Oxygenation

echocardiography

pre-ECMO RV support

cannulation options