Update Course Rewind: ECMO 2018

Hey there listeners, this is Rod Gerardo, research resident at Cincinnati Children's Hospital Medical Center, and if you haven't already, download the state current pediatric surgery app, it's in the Apple App Store, it's in the Google Play Store, but if you want more content than what's in there, if that's even possible, maybe you want just fresh content, then you gotta sign up for the 2021 pediatric surgery update course. It's a virtual conference this week, August 27th. So go to Globalcast ND.com, register today. It's interactive, it's virtual, you can talk to pediatric surgeons across the globe. And we're gonna give you sessions, kinda like today's podcast. Enjoy. Today, to give you a little bit of a taste of what the update course is like, we're gonna go back to a 2018 talk on ECMO or extracorporeal membrane oxygenation. So to kick things off, we're gonna hear a case from Alex Cassar. She's a general surgery resident at UT Health San Antonio. It starts with a 14-year-old male, previously healthy. He had flu-like symptoms for like 24 hours, got increasingly lethargic and fatigued, and her parents brought him to the emergency room with shortness of breath and fever. Oh, I guess I forgot to tell you, this session isn't about like a neonatal. Or infant ECMO, it's actually about older child ECMO or pediatric ECMO. So this 114 year old boy, once he comes in, has to get emergently intubated, is hypotensive, unresponsive to fluids, they start vasopressors. Now, scroll down under the media player, look at that first image, because his X-ray looked something like this. And from the looks of that X-ray, you can imagine that his ventilary parameters were not great. He had a peak inspiratory pressure of 45. His peak was 20, his FIO2 was 100%. And then on top of that, he's already on multiple pressors and requiring intermittent bagging to keep PAs in the low 80s with a PAO2 of 50. Respiratory PCR came back positive for H1N1. And that's when we get the call as the pediatric surgery team, they consult us because he doesn't seem to be responding to any of their therapies. But he needs to go on ECMO. That's Doctor Ron Herschel. He's a pediatric surgeon at Mott Children's at University of Michigan. Um, also, I was gonna talk about the indications for ECMO, but this isn't really that kind of talk. If you want the basic refresher, go back and listen to our podcast on ECMO with Doctor Samir Gattapali. So for this patient that, as we recall, is a 14 year old boy with ARDS on high ventility settings and on pressors. Which ECMO modality would you use? You have a choice of going veno arterial or veno venous. So let's think about the pros and cons of each. Let's start with veno arterial. I mean, there are some good things. It offloads the right heart. It actually increases the afterload of the left heart, but you don't have any recirculation, which is, which makes oxygen delivery much better. Vino venous, on the other hand, Can give you normal left ventricular afterload and reduced risk for a systemic emboli coming out of the circuit because it goes into the venous side. So then the obvious benefit, you're not cannulating an artery, which means that you're not going to get ischemia to a leg or stroke, uh, stroke because you cannulated the carotid or whichever it might be. So VV is, is markedly preferred. The, the best approach is to go VV unless you have specific reasons why you. Need to go VA. OK, Doctor Herschel, so we've decided that this patient definitely needs to go on ECMO. Then we weighed the pros and the cons of VA versus VV and we decided VV is probably the best way to go. But Alex has another question. What is your preferred cannulation site for VA ECMO? And we have carotid, uh, carotid IJ combination, femoral versus, uh, with femoral R IJ subclavian and I. IJ or femoral, and then femoral IJ. Um, first off, I just want to talk about VAV. So scroll down under the media player, look at the diagram for VAV. These are the problems with draining femoral vein to femoral artery. OK, one of them is ischemia of the leg. The other is that what's called North-South syndrome. So, if you look up at the, at the purple arrow up in the heart, the blood coming out of the heart is, it's hypoxic, and it's feeding the head, and it's feeding the heart, you know. The coronaries, and it's feeding the upper arms and so on. But then the blood coming from the ECMO machine, that's the red arrow, it's like very well oxygenated. So the legs and the lower body are really well oxygenated, and the things that we want to be well oxygenated, like the head and the heart are poorly oxygenated. And so we call that North-South syndrome. So what do we do for that? Well, Doctor Herschel says you could just, from the ECMO machine, plug into the right IJ. And then you're putting oxygenated blood into the right atrium, that's gonna help perfuse the upper torso. Pro tip, you could also put a Hoffmann clamp on the blood that's coming out of the cir circuit that goes into the femoral artery, and so you can actually adjust how much blood goes into the right atrium, how much goes into the, into the femoral artery. The femoral artery really is, has re-infusion for blood pressure support, and the one that goes into the right atrium is for oxygenation of the upper body, and so you can adjust them. So speaking of ischemia of the. Upper part of the body. That could include the brain. So scroll down under the media player, I'm gonna link an article from Doctor Gapalli about stroke rates. Here's Doctor Herschel. He took the 30,000 patients in the registry, and he looked at the stroke rate at a variety of different ages, right? All the way up to, you know, neonate up to 18 years of age. And the stroke rate is about 5%. Um, if you cannulate the carotid, but look, the stroke rate, if you don't cannulate the carotid, is only about 1% less. Oh, so maybe it's not necessarily about where you cannulate, but the fact that these patients are just very sick and they have high stroke rates. So, caning the carotid is not, like, it's not the, it's not the end of the world. I just want to say that. And I, and, and what I really want to make as a point is, you have someone who's really sick, OK? Don't mess around. Because you can sit there messing around trying to knock can at the carotid when, when the best thing for them is to get on VA bypass and get them stabilized. Wise words, Doctor Herschel. So, let's talk about the size here, because we are talking about older patients that were doing this, right? OK. And this, this just, at UFM just uh as a, you know, to give you what we do in VA for child less than 35 kg, we do carotid IJ. You get over 35 kg cause you were saying in, in an older patient, yes. And um we might go the, the groin and then, uh, or, or the carotid and IJ as I discussed. Remember, we, we would really try to go VV. OK, so in the older child, we're probably going to cannulate the groin, but do you do anything specific to try and decrease ischemia to the lower extremities? Uh, there's some data from, uh, Charlie Stoller's group, which looked at femolartic cannulation from 2 to 22 years of age. But the bottom line is, even with a distal profusion cannula, they ended up in 9/11. 11 having ischemia. So, where are you plugging in the distal profusion cannula? We actually, in older patients, will do um a posterior tibial artery, and we do it routinely. But there are also some other new techniques out there that might be worth trying. Putting a, a, a side cortex onto the femoral artery, also onto the subclavian artery. So, a lot of adult practitioners use that routinely. That is a subclavian access, and that way, you're not dealing with the leg, arm tolerates things a lot better. So, we call it a stovepipe uh cannulation. OK, that's really fancy and looks very complicated, but let's go back. We said that VV is probably the best way to go. What types of VV ECMO Do you think would be best for this patient? And we have BV with uh draining from the femoral and reinfusing into the IJ draining from the IJ and reinfusing into the femolar, femoral, or using a double lumen cannula. All right, so I promise this isn't like a commercial for University of Michigan, but the next article that we're gonna talk about is about what's called the M bridge, femoral atrial or atrial femoral. I'm sorry, say that again, please. Right, we had cannulas in the Femoral and cannulas in the IJ and one cannula in the femoral, and one vein and one cannula in the IJ. And then what we did was we either drained from the IJ and went back into the femoral or drained from the femoral and went back into the IJ. It sounds really complex, but just look at the diagram in the article. The bottom line is what you see in the graph, drain, femoral, infused in atrial, and that's because you don't recirculate. Huh. Makes sense. So that must be what like everyone around the world is using, right? But actually, this is the, you know, across the country and even the world now. The Avalon is the, is the preferred. Access. I sense a butt coming on. You have to place the distal tip into the inferior vena cava, and that's not easy to do. You got to get a wired into the inferior vena cava, but it's a single cannula. Patients, you know, I mean, it's, it's well tolerated, um, and it allows more mobility. All right, let's do another hypothetical. Let's say this patient got VA ECMO, and then throughout the course, there's blood coming from the ET tube, you shoot a chest X-ray, and there's an apical pneumo. I got to ask you, Doctor Herschel, is this resident going to put a chest tube in? Because it says, sit on your hands, don't put lines, don't put chest tubes unless you have to. If they're physiologically compromised or you really think that it's, it's compromising their gas exchange, uh, or their ability to come off ECMO and so on, fine. But we've had plenty of chest tubes we placed. You put a chest tube in, I would say about half the time, you're going to end up doing a thoracotomy because of bleeding. And then that's a whole pathway where you're packing the chest, leaving it open. It's not a good time. So, What do you say we do a little summary? You would like to use VV whenever possible. Uh, if you need hemodynamic support, uh, then using veno arterial is reasonable. And if you do have to go veno arterial, then the preferred site of cannulation in younger children is the carotid artery. Uh, in those greater than 35 kg, it's going to be the, uh, femoral artery and femoral vein, plus or minus an extra cannula in the IJ vein. Now, if the patient is like really physiologically deranged and very sick, you really need to do something, then that's OK if you jump straight to carotid IJ. If you do use the uh femoral artery, uh, uh, cannulate uh soon after with a posterior tibial artery, uh, prophylactically, uh, Don't wait for ischemia to set in. If you're going to go VV you should use a double lumen catheter. If you are going to use an internal jugular and femoral cannula, use the approach, which is uh uh draining from the femoral and reinfusing into the atrial. When you place that double lumen catheter, Better safe than sorry. So, first of all, it's OK to use the OR if you need to. Second, use fluoroscopy. And third, if you could, use echo as well. And finally, uh, if you have a, a small pneumothorax, um, don't be in a hurry to press, to put in the chest tube. I'll tell you what you should be in a hurry for, registering for the 2021 pediatric surgery update course, go to GlobalcastMD.com. It's all virtual this year. You can log in wherever you are and watch sessions just like this. Interact with pediatric surgeons from across the world, ask questions, ask me a question. I'm not gonna answer it, I'm just gonna ask the panel if I'm being honest, but it's gonna be a great time. Follow us on social media to stay up to date with what's going on during the conference, you're gonna love it. But until then, I'm Rod from Cincinnati Children's, and remember, knowledge should be free.