PARAG PATEL: Thank you very much, Juan. And thanks, everybody, for joining me a week before Thanksgiving. We are now entering the world of mechanical circulatory support. Over the next several weeks, we'll really be kind of focusing on this in terms of our lecture series, and [INAUDIBLE] is on this morning. And [INAUDIBLE] or Dr. [INAUDIBLE] will actually be giving our next talk in a couple of weeks on surgical considerations.
So this is really going to focus on hemodynamics and the selection of management a mechanical circulatory support in cardiogenic shock. And it's going to add on several of the basic kind of hemodynamic information that we discussed during hemodynamics and the management of heart failure. So you'll see that a lot of the slides are similar to before. We're adding on what we've learned from our lectures in July and August.
So as you know, I like actually giving clinical scenarios, which is sometimes hard to do with Zoom. So what I'll do is I'll just go through the case. I'll give everybody about 10 seconds to think about the answer. And then I'll actually talk about the answer and go from there.
So our first case is a 63-year-old with non ischemic cardiomyopathy, EF 25%. Comes in afebrile, with the blood pressure of 75 over 50, a heart rate of 125, a respiratory rate of 20, and trace lower extremity edema. The lactate is 5. Labs are [INAUDIBLE] 2.5. Baseline is 1.4.
LFTs are up at 600. The troponins are normal. The patient was on Dobutamine and through a PICC line, we were able to ascertain that the CVP was 20, so that [INAUDIBLE] filling pressures were high. And the SVO2 was 28%.
All of the following are reasonable therapies to consider until further data is obtained. I gave you the answer before I pushed it there. Except, so which is not the appropriate choice, is it mechanical circulatory support is not needed and add milrinone. Is it add a balloon pump, add an Impella CP, add a ProTek Duo, consider an Impella RP and an Impella CP, or VA ECMO?
So as you saw here, I think the answer to that is the least reasonable, is actually adding milrinone. You have a patient who is quite hypertensive, in renal failure, is starting to develop organ dysfunction as well. And a very, very low SVO2 of 28% so additional [INAUDIBLE] may not actually lead to a salvageable outcome.
And so it's really important to notice-- or important to identify shock early, before you get into metabolic disarray. Typically, you start off with a hemodynamic problem. And then slowly over time, you move towards a hemometabolic problem.
And once you have a hemometabolic problem or cardiometabolic problem, it is much harder to dig yourself out of cardiogenic shock because then you're dealing with multi organ failure, you're dealing with acidemia, the [INAUDIBLE] chrome acidemia and renal failure, et cetera.
And so when you start getting deeper into the hemometabolic state, your equation's going to have to incorporate addressing all of these four issues. You need to consider circulatory support to allow for systemic perfusion, ventricular support to provide RV unloading, improvement in coronary perfusion, particularly in your ischemic patients. And finally, renal and hepatic unloading to optimize hemodynamics from a renal function standpoint and allow for further and loading the heart.
And so really the idea here is that you want to identify cardiogenic shock early. And the deeper you're in this cardiometabolic kind of milieu, the more likely you're going to need stronger support. The other thing to realize is that once you start one or two drips, adding more drips really isn't going to help you much.
So this is data from a shock registry of about 200 patients. And they looked at survival based on number of inotropes when in cardiogenic shock. And as you can see here, once you get the [INAUDIBLE] inotrope pressor a number, your [INAUDIBLE] mortality is quite high with 60 to 70%. So you're not going to get much bang for your buck the higher inotropes and pressors you're going in. And so it's really important to think about therapies at that time.
It's also important to note that you don't want to wait too long for mechanical circulatory support, especially those that are deep in cardiometabolic shock. This is data also looking at the acute MI cardiogenic shock registry, looking at onset to mechanical circulatory support implantation and its relation to in hospital survival rates as a function of shock. And so what you can see here is patients who had mechanical circulatory support within 75 minutes of presentation with cardiogenic shock had better outcomes compared to those who had a delay in therapy. And so what we've learned over time, is that the trigger to actually consider mechanical circulatory support at our institution as well has actually been earlier reports of cardiogenic shock.
So what device do you use? How do you actually decide what device you're going to use when you decide, OK, it's time for temporary mechanical circulatory support. I think the biggest thing to realize is that different paths can lead to the same outcomes, as long as you know strengths and weaknesses of each path.
So if you're going from Jacksonville to Ocala, you may be able to go 3 different routes, but you need to know which route actually has issues. This is red route here as a lot of speed traps, and so that may be a advantage or disadvantage to taking that. And the same idea with Impella, ECMA, et cetera, you really want to get an idea as to what the strengths and weaknesses of each one. And tailor the therapy based on the clinical presentation of the patient and the patient features.
So let's get to that first. So there are several LV support options, these don't include all of them, but they include the majority that we typically use here at Mayo. And several of them actually involve options that can be used at several of the hospitals in North Florida.
So we have our balloon pump, which is a pulsatile pump that is not entering the left ventricle. It actually sits within the aorta, and I'll get into that in a minute. You have your axial flow pumps, one usually is-- one type is placed within the femoral artery, so the CP typically is placed within the femoral artery and is usually utilized for short term support.
The Impella 5.5 can actually be placed in the axillary position and actually provide a little bit longer term support and allow for rehabilitation of a patient with support. And then the centrifugal pumps that are typically utilized are TandemHeart. The TandemHeart-- basically you have a in flow cannula that sits in the aorta. And then blood is pulled out to a centrifugal pump.
I'm sorry, I'm just going backwards here. We have an inflow cannula that sits in the left atrium. That's placed-- it's actually placed retrograde up the IVC and utilizing intracardiac echo and a septal puncture. So blood is pulled from the left atrium, goes into the pump, and then is pushed up the aorta.
And then CA ECMO, which we'll talk about in a second. So both the tandem and the VA ECMO are extracorporeal pumps and these three large corporal pumps over here.
So let's talk about the features of each one. So with the balloon pump, again it sits within the aorta, it allows for diastolic augmentation of coronary perfusion and it also allows for systolic augmentation of poor flow by reduction in the systemic vascular resistance. It sits in the aorta, it provides an augmentation of about 0.5 liters per minute of flow.
It requires a small cannula size of 78 French. The femoral artery size that is required for a balloon pump is about 4 millimeters. Again, the balloon pump now, as you know, also be placed in the subclavian axillary position as well.
You do need synchrony or at least a stable rhythm for a balloon pump to work well. And a lot of you guys have managed a balloon pump when somebody's in AFib with RVR or sinus tach and those tend to be suboptimal situations for a patient requiring support. Balloon pump does not provide oxygenator.
When you look at the hemodynamic profile, the biggest thing it does is it reduces afterload, and by doing so you reduce LVEDP and increases workflow or coronary power. Of course, it also increases coronary perfusion through diastolic augmentation and conflation.
The Impella 2.5 and CP, both of those are retrograde placed through the aorta into the LV. So it basically pulls blood through the left ventricle and pushes it down the aorta. It provides around three maybe four liters per minute of flow, the CP is definitely a stronger device than the 2.5.
The cannula size is definitely bigger than the balloon pump, so it may be difficult to place in a really petite or young petite female or male or a young patient. Cannula sizes are around 13 to 14 French. You do need a femoral artery size of around 5 millimeters.
But the nice thing with this is don't need synchrony or stable rhythm. This device doesn't have an oxygenator. When you're looking at kind of the hemodynamic profiles, the biggest thing to realize is that all three, balloon pump and Impellas, will actually-- sorry about that. All three will actually improve afterload or reduce afterload, all three will reduce LVEDP. But the Impella will actually reduce LV preload as well.
When you actually look at the Impella 5.0 or 5.5, five this again, is kind of an extension of the Impella series over here. Typically, again, placed in the axillary position by our surgical team. You can get around 5 to 5.5 liters of flow with this device, the cannula size is around 21 French.
You need a sizable femoral artery of 7 to 8 millimeters. Synchrony is not needed, again. And the hemodynamic profile is about the same as all the other devices. The reason why we typically utilize the Impella 5.0 or 5.5 over the CP or Q5, is if we feel we need prolonged mechanical support. It does have less hemolysis than the smaller devices.
There is a risk for vascular complications with any of these devices. But one of the other nice profiles is that it allows the patient to be ambulatory and allows us to kind of provide strong rehabilitation with that support. We talked to earlier about the TandemHeart. Again, it's a little bit of a tedious procedure because you do need to do a septal puncture. In the cath lab, you need to play.
But the one benefit of the tandem devices is that they have an oxygen meter that you can add. So going through the profile again this pulls blood out of the left atrium and pushes it up the aorta, you can get about 5 liters of flow with this device. Cannula sizes are 17 arterial and 21 for venous. Femoral artery sizes are around 8 millimeters.
You don't need a stable rhythm you have the ability to utilize an oxygenator. But the one thing to realize with the TandemHeart and ECMO, which I'm going to talk about in a second, is that the after load increases because you have retrograde flow up the aorta. And so that makes it harder for a sicker heart to actually unload. And so you just have to watch your ability to unload when you actually increase after load like this. And it also makes it harder for the LV to kind of remodel over time and improve, so keep that in mind.
And then when you have ECMO, there are multiple configurations of ECMO. Here is kind of a configuration of peripheral ECMO where you can pull blood out of the IJ and push it up the femoral artery. Dr. [INAUDIBLE] recently did a very nice upper extremity configuration for peripheral ECMO in a patient with giant cell myocarditis, where he actually pulled blood out of the IJ and they had a axillary placement of the oxygenated blood. So the cannula in the axillary artery.
And so when you have that type of configuration you can actually rehab the patient. You have the patient walk, et cetera. And so when you actually look at the profile of the ECMO, again, many different configurations. The configuration I showed you, you're pulling blood out of the RA, you're going into the aorta.
You can imagine this provides both right and left support because you're completely bypassing the right ventricle. All the other devices need a functioning right ventricle. So in VA ECMO the cannula sizes are 16 arterial 21 for venous. You need a femoral artery of around 8 millimeters, you do not need stable rhythm.
An oxygenator is available. So if you're worried about oxygenation you really want to, again, think about VA ECMO or TandemHeart. Again your cardiac power is pretty strong. Your after load is quite high so that's one of the challenges with ECMO. And the rest of the profile is pretty similar.
And that was left-sided devices, and real quickly we'll talk about right-sided of devices. So in terms of right-sided devices, there are devices that provide direct RV bypass and ones that provide indirect RV bypass. So when you talk about RV bypass, the actual flow pump that we typically utilize is an Impella RP, which is placed in the groin.
You have the option to place a ProTek Duo catheter in the IJ and provide extracorporeal centrifugal flow that protects the RV. And so both of these are isolated RV devices. The benefit of the ProTek Duo is that you have the ability to ambulate your patients, the Impella RP is a pretty large device that sits on in the groin.
All of these bypass the RV, so you can see if you look at the circuits down here, blood flows from the RA directly to the PA. So the assumption is when you're putting in these devices isolated, so alone, you have to make the assumption that the LV is going to be able to tolerate the increased blood flow. And so all three of these devices will markedly increase blood flow to the left, and you have to be certain that if you're going to do that, the left ventricle is able to tolerate that increased preload.
Indirect RV bypass involves VA ECMO. And again, you're pulling blood out the RA and going straight to the LV. And so you're really bypassing this entire circuit. And so this is a very good choice for biventricular failure or isolated RV failure, where you're not sure about the ability of the left ventricle.
Because sometimes, as you'll learn, as I'll show you here shortly, when you have a very weak LV, you're not actually challenging-- when you have a very weak RV you're not actually challenging the LV much, and so you may not be able to appropriately assess the capabilities of the left ventricle. I'm going to stop there and answer any questions, and then we'll keep on going. Are there any questions for the group?
OK, great, I'll keep on going here. So how do you choose what is right? There are certain things that you need to kind of assess when you try to decide what type of pump you're going to use. So the first thing to keep in mind is the strength of each of these pumps.
And so when you move from left to right, you're going to have greater cardiac power output or greater output from your device. So if you need a very strong device, you're really looking kind of at these three devices, Impella, Tandem and VA ECMO.
If you're looking at kind of lighter support for a shorter period of time, you're looking at kind of the balloon pump and the Impella CPs. You're going to look at cannula size as well, again smaller patients may not be able to tolerate some of these larger devices. And so you want to look at cannula size and appropriately estimate the utilization based on the size of the artery that you're going to utilize.
And finally, you're going to also look at oxygenator and see whether you need an oxygenator or not. So if a patient has borderline oxygenation, you may not want to utilize the devices on the left. You may want to consider VA ECMO or a TandemHeart.
Now the most important thing is, so these are features of the pump, but most importantly, how you select your devices is utilization of the basic hemodynamics. So basic hemodynamics are essential in the selection of temporary mechanical circulatory support. And you want to utilize the hemodynamics to help yourself in terms of deciding what type of devices you need.
Now the thing is that-- I'm just going to remind you guys about some of the basics of hemodynamics, this is an extension of my prior lectures. But first of all, when you actually look at the data, the data actually supports utilization of invasive hemodynamics. When you have acute MI and cardiogenic shock.
So this is registry-related data presented by Bill O'Neill in 2018, where they looked at, I think it was around 2,000 to 3,000-- I'm sorry 1,300 patients, who underwent acute MI cardiogenic shock through the registry. And they stratify patients and those who had no hemodynamic monitoring and hemodynamic monitoring. And those who actually had hemodynamic monitoring had less mortality than those who had no hemodynamic monitoring.
And that may not be the swan that improves outcomes, but it may be the ability to utilize that data to optimize patients. Or it may be the expertise of the center, because most centers who utilize hemodynamic monitoring may be kind of large scale academic centers who are used to managing sicker patients. And so again, how do we utilize hemodynamics?
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- --hemodynamics we need to think about three major components.
Oh hold on one second here.
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I apologize. Let's see here, I don't know why-- let me erase that there, I apologize. So when actually looking at hemodynamics, it's important to, when you have a patient that's crashing, you want to break it down into preload, contractility, and afterload.
And it's important to note that shock involves a derangement in any of these three hemodynamic parameters. And so it's imperative that when you have somebody who's crashing, you're going to want to estimate what's going on with these three components either invasively or minimally invasively or on exam.
And so when you actually look at invasive hemodynamics, remember the rules of 6's, I think I taught that to you guys earlier. If you understand 6, 12, and 24, you can actually derive all the normal numbers for invasive hemodynamics. If you use the concept that the atrium ventricle filled during diastole, so you need equalization in pressures.
And the ventricle and the vessel is actually filtering during systole, so you need equalization of pressures over there. So rules of 6's, 6, 12, 24, you know that these filtering diastole. So the RV diastolic pressure 6, know that this fills during diastole, so that you know that the LV diastolic pressure's 12. Know this fills during systole, so this [INAUDIBLE] pressure's 120 and 24.
OK and if you understand that, you understand what the normal waveforms will look like when you put in a PA catheter. Typically 6 or so, when you put it in the right atrium. Typically 24 over 6 in the right ventricle, 24 over 12 in the PA, and around 12 when you wedge.
So that involves your preload, and then you also need to look at contractility and resistance. We like using cardiac index, normal cardiac index is 2.5 to 4.2 liters per minute per meters squared. And in terms of resistance, systemic vascular resistance should be around 800 to 1,200 dynes-seconds per centimeter to the fifth.
Now if you have somebody who is crashing, and you don't have a central line in place-- I mean you don't have a PA catheter in place, you can start off with the poor man's swan and utilize a central line or PICC line with an adapter to look at the central venous pressure and the SVO2. OK and a normal SVO2 is around 60%, and it's important that when you interpret an SVO2, you understand that there are several parameters that can actually affect your SVO2.
So oxygenation through the lungs can affect your SVO2, So if you have issues with oxygenation that can reduce your SVO2. Hemoglobin, or if you think of this like a train going around a circuit, the ability to carry oxygen can affect your SVO2, your output or the speed of the train, and finally your oxygen consumption or your ability to pull off oxygen from the train affects your SVO2.
So in order to make the assumption that your SVO2 correlates with oxygen delivery, you have to make the assumption that your oxygen arrival, your oxygen carrying capacity, and your oxygen uptake is relatively unchanged. And so if those three are unchanged, you can feel comfortable utilizing your SVO2 for output.
So SVO2 again, is a surrogate for index if those three parameters are stable. Remember on a venous blood gas, you're going to want to look at the SVO2 percent and not the PO2. Sometimes people-- have had respiratory therapist report this number, the 37.2. Remember, it's not that, it's the SO2 percent that gives you the SVO2.
And it's also important to note that the poor man's swam may tell you whether the heart is the issue with shock, but it's not going to distinguish in a granular level between RV, LV, or BI-V failure. And so it's really important to note that you need more granular information to really get an idea as to which of the three here are causing your issues. And so that's where we use kind of more advanced hemodynamics.
So the one parameter that we like using is cardiac power output. So cardiac power output is and integrative measure of cardiac function that really accounts for two things. It accounts for the flow generating capacity of the heart and the pressure generating capacity of the cardiovascular system. And it integrates the two. And so cardiac power output equals MAP times cardiac output divided by 451. I like using Fahrenheit 451, the book if you guys recall, as a reminder as to that number.
And when you do MAP times cardiac output divided by 451, if your cardiac power output's greater than 0.6, that's normal. And if it's less than 0.6 it's abnormal. And when it's abnormal it suggests that your flow generating capacities of the heart, or your pressure generating capacities, are abnormal and you're going to have to address that. I'll get into details on that in a second.
The other thing to kind of realize when you actually get hemodynamic measurements is that you have to remember the RV, do not forget the RV. Because the RV needs to fill the LV in order for forward flow to occur. And we oftentimes forget the RV in the setting of cardiogenic shock.
And so really when you have invasive hemodynamics, not only are you looking at the left-sided pressures but you're really going to utilize the right-sided pressures and break down the invasive hemodynamics into right and left flow. So you can actually get an idea as to what's going on.
And remember that after you place left-sided support, right ventricular failure can actually worsen. So if you have a big baggy LV and you actually put left-sided support in, you're going to actually make the LV get smaller, you're going to shift that septum leftward, and you're going to actually increase preload. And so you're going to shift your lateral wall rightward. And so when you have a shift of the septum leftward and the lateral wall rightward, you're changing morphology of the right ventricle and that in itself is going to lead to RV dysfunction.
So how do we look at RV dysfunction? There are multiple different measurements, but I think this is a very simple tool to utilize. This is PA pulse pressure index or PAPi. So that stands for the ability of the PA to generate-- I mean of the RV to generate a pressure. So that's PA systolic minus PA diastolic, divided by your backflow or your central venous pressure.
So PA systolic divided by PA diastolic over CVP is PAPi. And the bigger the PAPi the better. So if you have no temporary support in place and your poppy is less than 1, that's abnormal. And if you have temporary mechanical support in place, or have an LVAD and your PAPi is less than 1.5, it's abnormal.
So how do you integrate these hemodynamic measurements when you have a patient on temporary support or not on temporary support? So the first question you're going to ask is, is there adequate flow? And so how do you assess for adequate flow?
You look at your cardiac power output, look at your SVO2, if it's greater than 60%. Or you can look at cardiac index. And then if there's not adequate flow, so if these parameters are low, then you want to go to question two. And say, if there's not adequate flow is it because of the RV or is it because of inadequate LV support?
And that's where you utilize your PAPi. And if your PAPi is less than 1.5 when you have mechanical circulatory support, then you know the RV is your issue. And if your PAPi is greater than 1.5, then you really need to pay attention to LV and see, is your support adequate? You can use PA pulse pressure, CVP, and RV TAPSE as well, but we typically here we'll start off with the PAPi to troubleshoot.
This is the most important slide from a hemodynamic standpoint for our fellows today. I think this kind of sums up everything I've taught you. Is that when you have a patient and if there is refractory shock, what you're going to want to do, is you're going to want to break it down into three types of shock. Biventricular shock, LV dominant shock, and RV dominant shock. So let's start off with parameters for LV dominant cardiogenic shock.
In LV dominant cardiogenic shock you will have a low cardiac power output, less than 0.6. You will have a normal or borderline PAPi, so in this case 1. So as you-- if you go to the questions do you have enough forward flow? No, because the CPO is less 1.6. Is it because of the right side? No, because your PAPi is greater than 1.0.
And typically in these patients, you'll have a low RA and a higher wedge. And that kind of dictates or shows that your problem is LV dominant. In an RV dominant cardiogenic shock, you'll have a low cardiac power output, but the problem is your right side.
And so your PAPi is going to be low and your RA is typically going to be higher than your wedge. So you'll have an RA greater than 15, and your wedge is going to be less than 15. And so if you have this hemodynamic profile, you're typically dealing with RV dominant cardiogenic shock.
And then biventricular shock. Basically, you're going to have a low cardiac power output, you're going to have a low PAPi, so this is suggesting right-sided failure. But the difference is that you're still having a high wedge and so typically when you have isolated RV dysfunction that's severe, you're not able to push right to left and so you're not able to generate a high wedge
In biventricular failure, typically you're going to have a high wedge as well. And so when you have that high wedge, that is your sign that maybe it's not just the right side, that maybe you're also dealing with left-sided failure. So once you identify the type of cardiogenic shock, the next step is going to be looking at whether you have hypoxemia or not.
If you have hypoxemia again, your choice for temporary support becomes limited. So if you have hypoxemia and you have biventricular failure, you really need to think about the TandemHeart or the VA ECMO circuit. Or CentriMag with an oxygenator eta or bilateral CentriMag with an oxygenator-- biventricular CentriMag with an oxygenator.
If you do not have hypoxemia, and you have biventricular failure, you can think of a BiPella or a TandemHeart with the ProTek Duo. There are many different left and right configurations you can do, or you can still just consider a VA ECMO as well.
If you have LV dominant cardiogenic shock with hypoxia, again VA ECMO or TandemHeart. If you don't have hypoxia, then you can use one of the Impella devices. If you think it's going to be for more than a day or two, really consider the 5.0, if you have the surgical team and the availability. So that you can ambulate your patients.
If you have right-sided dominant cardiogenic shock and you have hypoxia, then again, total artificial heart and VA ECMO are what you're going to want to consider. And if there's no hypoxemia, then think about a right-sided Impella or ProTek Duo.
OK how do you know there's no cardiogenic shock, or it's not refractory? It's when your CPO is greater than 0.6, your PAPi's greater than 1.5, and you're filling pressures are low. And if you have this, then you really can start thinking about weaning your temporary support, once your metabolic disarray is optimized. And as you develop optimization of hemodynamics and as you develop recovery of the heart.
And it's also important to note that it's more than just hemodynamics. And you really need to think about a bridge to where. A 98 year-old in a nursing home, who is wheelchair bound, coming in cardiogenic shock may not benefit long term from temporary mechanical circulatory support.
And so what we like doing here is we like involving a multidisciplinary discussion with our intensivists, interventional cardiology, CT surgery, our transplant team, sometimes palliative care, and the ER is also involved. But really, we want to have our team do a multidisciplinary assessment so we can make sure that if we are going to commit to this route, that we give the patient the best possible option. And that the patient has the best possible chance at improving.
So with all that information now let's get to our questions. So let's go back to that patient who came in with low output heart failure, lactate of five, LFT's are high. Troponin looked OK. Let's give you hemodynamics this time and let's say that the MAP is 50, the cardiac output is 1.5, the CVP is 18. The PA is 24 over 14, your wedge is 12, and your SVO2 is 46%
So what form of mechanical circulatory support is best? I'll give you guys a couple of seconds to think about this. So in this case, we want to go back to the hemodynamic profiles that I taught you about-- I talked about. So we want to look at what is the cardiac power output and what is the PA pulse pressure index?
So cardiac power output, remember is mean arterial pressure, times cardiac output divided by 451. And I calculated that to be 0.17. And the PAPi is the PA systolic minus the PA diastolic, divided by the CVP and that is 0.56. So in this case, you have a low cardiac power output and you have a low PAPi.
And then you're going to look at the wedge, because if the wedge is high, then you're dealing with biventricular failure. But in this case, the wedge is actually looking OK. And so in this case, what you're probably dealing with is RV failure.
And so when you go to this question, and you say which form of mechanical circulatory support is best, you're really thinking about either a ProTek Duo, RP and CP Impella, or VA ECMO because all of these support the right side. Any questions so far?
Great. So remember, you don't want to forget the RV. And remember that RV failure can mask LV failure, and so keep this in mind as we go through this question for a second here. So sometimes, you may not know the left-sided capabilities of the heart because the right's not challenging the left.
And so let's get-- we're going to skip this for a second. We're going to go to that question here for a second. So in the same case, you had the patient and you decided to put a CP Impella in place, OK? And 24 hours later, the lactate is not improving, the LFT's are worsening and the creatinine is worsening.
You look at your hemodynamics and your mean atrial pressure is 57, your cardiac output is 33.2, your CVP is 11, your PA pressure is 45 over 20. Your wedge is 18, your SVO2 is 55%. This time you actually directly calculate your cardiac power output as 0.4, so that is low. But your PAPi is OK.
So this is a case where you actually- no, I apologize. This should be Impella RP, RP is placed. But this is a case-- this should be RP, let me change it for you guys here. But this is a case where-- this is a case-- oh, I'm sorry. The slides kind of moved forward.
We should be here. So we put a RP Impella in the patient and your mean arterial pressure is 51, your CVP is 12, your wedge is 23, your SVO2 is 38%, your cardiac power output is low, and your PAPi is adequate. So which form of mechanical circulatory support is best here?
You have a patient with low cardiac output and a adequate PAPi. And so in this case, you will need a left-sided support. And so here's a case where you put a right-sided device in, and you unmask left-sided failure. And so the options for this patient is actually going to be an RP Impella, or a CP Impella or a VA ECMO.
And so if you put a right-sided Impella in place in somebody who has right-sided failure, you're not done. You need to actually look at hemodynamic subsequently and see is that support adequate. Do we need to do anything else? OK and so again the RV may unmask LV failure.
And this is kind of a BiPella placement for a patient, where you actually have a Impella CP sitting in a left ventricle and an RP Impella on the right. And that can provide ventricular support, especially for people who don't need oxygenation or if you're going to do it short term. Remember both of these are placed in the groin, so that is one kind of issue with regards to that.
OK so now, we're going to change this. We're going to go back to this case here. And you put the CP Impella in, the lactate is still worse, the creatinine is worse. Again, these are the hemodynamics. With a CVP of 11, PA of 45 over 20, wedge of 18, and a SVO2 of 55%.
In this case, you have a low cardiac power output and you have a PAPi of 2.3. So you have low forward flow, but you're right-sided support's OK, even though you have an RP and a CP Impella in place.
So this is a case where your CP Impella is not strong enough, and you need to think about either upgrading to either a 5.0 or 5.5 Impella, or progressing towards VA ECMO. And so in this case, they didn't give you the option for a 5.0 Impella or 5.5 Impella so you would want to advance to the VA ECMO.
And so pearls for this case is remember that the right is tightly linked to the left. You need continuous assessment of hemodynamics to optimize temporary mechanical circulatory support, even after you provide the support. And then remember this, is that addition of isolated RV support is not adequate when you have severe metabolic disarray or LV myocardial depression.
So if your left ventricle is weak and your wedge is higher than maybe 15, just putting in a right-sided device is not enough. And the other thing to keep in mind is sometimes when you have a lactate of 10, even though you had adequate LV function prior to hemodynamic compromise, support with the right side alone may not be enough because the left side may be injured from the metabolic disarray.
And so sometimes when you have severe metabolic disarray, even if you feel the left side of the heart is strong enough to support a right-sided device, you may need to consider biventricular support. Any questions so far?
FEMALE SPEAKER: Dr. Patel?
PARAG PATEL: Yeah.
FEMALE SPEAKER: I do have a question. So is this decision made, whether you want to support the RV or the LV, prior to them getting the device implanted? Like for example, if someone does have-- if it's their RV that's failing, but you're not sure is the LV going to be able to keep up or is the metabolic disarray going to resolve. Are you just making that decision that we're going to do RV and LV support prior to them getting the RV device?
PARAG PATEL: So in my opinion I think it's best to utilize hemodynamics if you have the time and ability. So obviously if the patient's crashing, then minutes count. Sometimes you throw in a device, whatever you think is going on, and then you get your hemodynamics subsequently to assess adequacy of support.
But in the ideal world, which is not always the case, you would use your hemodynamics to decide. And then if you guess one way, it's important that you have a swan in place to see if your guess was correct. And so let's say you even have hemodynamics and it looks like the right side is the issue and the left isn't.
Even after you place the right-sided device you should be following hemodynamics because the left-sided failure may [INAUDIBLE] 4 hours later, 6 hours later, or even 12 hours later. And so you really want to kind of watch it in real time. Does that answer it?
Yeah, thank you.
All right so here's an example where actually the opposite occurred. So I told you that whenever you put a right-sided device, beware of left-sided failure. Also remember that when you put it right-sided device in-- I mean a left-sided device in. So whenever you put a left-sided device in, you want to also be aware of the possibility of provoking RV dysfunction.
So here's a patient that was hypotensive, pressure's in the 80s, a PA pressure of 50 over 30, an RA of 30. And they actually put a CP, a left-sided device in the patient. In a patient that is already-- has a PAPi that's under 1.
And so what you can see here, and this is a real patient. A CP is placed and what you can see here is that the PA really didn't change much. Your maps really didn't change much, but the one thing you notice is that your RA pressure shot up.
So you've increased your preload to the right side with the already weak RA. And so then you have coupling of your RA and your PA pressures. When you have a coupling in your RA and PA pressures, you're really dealing with RV dysfunction.
And so in this case again, aortic pressure is the same, PA goes up, RA goes-- I mean PA goes mildly up, but more importantly the RA significantly goes up. And you have RA to PA coupling. And so in the cath lab they recognized this, and so they put an RP Impella in place.
And this is where you start seeing adequate forward flow because now the right is pushing to the left. And so you see your aortic pressures go up, your PA pressures actually kind of improve because-- or go up a little bit, because you have right-sided flow into the PA. And your PA pressure actually goes down. So you have RA to PA uncoupling. So you have a separation between your RA and PA waveforms, suggesting you're having adequate right sided flows with this device.
And so just remember, I just want to highlight that the right and the left are tightly linked. And you really want to kind of look at how both are performing, both before and after temporary support. In conclusion, really want to understand that each have a mechanical circulatory support has both strengths and weaknesses. The support selection is tightly linked to hemodynamics.
And as a fluid processes, as I told-- you may put in one type of device, and then if it doesn't work, you may need to add a different device or change it out. So you want to use those hemodynamics to help you make decisions. And then a multidisciplinary approach is imperative to determine support type.
And I should add one more here, is that it's imperative to identify cardiogenic shock early and consider mechanical support or transfer to a place that can give mechanical support early, before you're deep into cardiometabolic disarray. Because once you're deep into cardiometabolic disarray, your ability to pull yourself out is very difficult.
And so with that I wanted to thank you and open it up to any additional questions.
JUAN: So one of the things that people always ask is how often you need to do these hemodynamics? You said you have to re check hemodynamics. Do you do them every 6 hours every 12 hours? In order to change your management. So how often in practice do you change your settings based on hemodynamics. Or how often do you do hemodynamics to change your settings?
PARAG PATEL: So that's a great question. I think-- I like doing hemodynamic-- I mean full set of hemodynamics every 6 to 12 hours, I think is enough if somebody's steady. But if somebody is very unsteady, then you want to use those hemodynamics rather frequently to figure out what's going on from a hemodynamics standpoint and troubleshoot the patient.
I really feel that-- one of the things when we get calls from different facilities, I think we see an under utilisation of labs, and hemodynamics, et cetera. And so people are getting labs in general maybe once a day or twice a day, and you really want to make sure that you're getting your labs. Every six hours you're checking your LDH, you're checking your lactate, you're getting your LFT's every six to eight hours. So that you can trend people.
Because these are the sickest of the sick patients in the hospital and you want to make sure that you give your patients the best chance at survival. And so I think utilization of hemodynamics every 6 to 8 hours in a stable patient and more frequently in less. What do you think, Juan?
JUAN: I agree. I mean, I think that the way we would do it in the clinic is of course, when we round in the morning and then again when we round for the second time formally in the afternoon around 4:00 or 5:00 PM. So we do at least twice a day. And we write the numbers on the board in the room. So that way people can see what the numbers were and they can see the trend.
And I think that the other situation would be if the patient declines suddenly or that will be the other time to do that hemodynamics. So it won't be unusual that someone crashes in the middle of the night and we come in and no hemodynamics have been done. There just the same swan and the pulse and blood pressure on the screen but nobody has collected [INAUDIBLE] PAPi, et cetera.
PARAG PATEL: I agree. And any other questions at all? All right so next week we do not have journal club, you get to enjoy your Thanksgiving weekend. Stay safe out there.
And then we will catch up the following week with Dr. [INAUDIBLE] surgical considerations for temporary mechanicals for long term support. Dr. Leone, any final words, sir?
JUAN: Don't eat too much turkey.
PARAG PATEL: Thanks, guys.