Assistant Professor of Anesthesiology & Critical Care, Dr. Emily Vail explains the types of donations from an ECMO consideration along with other practical factors. She will cover the assessment for donor eligibility along with its management and share US and local experiences. Through this information she’s able to provide preliminary outcomes and recommendations going forward.
@PennMDForum Um Doctor Piquet is a clinical mentor and teacher when I was, we were both at Columbia. So that's um a big honor to follow him in this presentation. I want to thank the organizers for the invitation. Um In terms of disclosures, I think this is in the pack up, but I do have some unrestricted research funding otherwise, no conflicts of interest. I'm gonna talk to you about organ donation from E C O specifically brain death and D CD thinking about how technologies to minimize warm ischemic time from donors might complement the work that other groups are doing with group perfusion and other modalities. Um I'm sorry, now I misplaced the thing. Yeah, the mouse I can use. OK, good. OK, great. So we're gonna talk about types of donation from some of the practical considerations for assessing uh donor eligibility. Talk about our local and national experience and then talk about some preliminary outcomes. I want to emphasize that the outcomes here are very difficult to study because donors on ECMO are fundamentally different from those from um not on ECMO and it's not yet clear that outcomes are sufficient for transplant programs to consider them equal the black. The missing part of this story is whether a transplant program will accept an organ the same way that they would from a different or a different type of donor. Um So which patients are we talking about? We know that some of our patients reported on ECMO will sustain complications that make them no longer eligible for recovery or for transplantation or other durable therapies in situations of neurologic injury or when continued support is no longer consistent with the patient or family's goals of care. There may be option to donate. There is a second group of patients in which mechanical circuit or support might be used specifically to provide or preserve opportunities for donation in the short or long term. This is either situations where E C L S is initiated and risk is never achieved or situations where we specifically use these technologies to support, assess and improve the survivability, the suitability of individual organs for transplantation. So the majority of organs transplanted in the United States come from deceased donors and the majority of those after brain death. But in the setting of critical or and persistent organ shortage, we have an increasing emphasis on the use of of organs after circulatory death. I think you've heard today about some of the ways that that's being done and clinically what this means for us is that there's a system of classification for these donors uh modified in the last few years. Broadly classified as uncontrolled and controlled, uncontrolled donors include Patti uh patients who die outside the hospital or situations of cardiac arrest in which resuscitation is unsuccessful. Control donation is what we're probably most familiar with. These are people supported by E C O who elect to withdraw a support and then um and then proceed to um to donation as well as a small group of a subset of patients who have a diagnosis of brain death that pro unfortunately progress to cardiac arrest. From this list. You can imagine scenarios probably with the exception of of class one where ACMA may be used to support donors um who are acutely unstable or undergoing active resuscitation and to again minimize that warm ischemic time. So the most recent clinical guidelines that we have come from the Toronto Group, this is published a couple of years ago in Canadian Journal of Anesthesia. It's a really useful very practical document that talks about a couple of the immediate clinical considerations that we might have in the IC with the bed side. So first for for potential donors after brain death, acma fundamentally changes physiology in ways that make tests for brain death, potentially difficult or problematic including residual medications absorbed into circuits. Uh the the possibility of a uh poor negative predictive value or false negatives in patients who require brain perfusion studies because of EMA circulation and challenges to acne testing for donors after circular charge death, individual hospitals, individual clinicians may be uncomfortable turning off the EMA circuit or need a special, special training or special protocols in order to do this. So this the guidelines are helpful because of these two algorithms that we won't go through in the interest of time. But this is the first algorithm which is a recommended modification of the brain death exam and acne testing specifically that goes through uh recommended initial flow settings, delivered oxygen settings and sweep settings with adaptations if C O twos are not rising as expected, as well as recommendations for where an EMA circuit gasses should be sampled. There's also a recommended protocol here for withdrawal of care for patients supported on ECMO um recommended steps in terms of when medications might be turned off, which clinicians should be present at the bedside. This protocol presupposes that the withdrawal is happening in the IC U. But the in the big take home message from donors after circulatory death is that local regulations, national regulations and hospital regulations vary tremendously. So, understanding what your institution is doing, what it, what um what's acceptable and um and what those protocols are. It is really important to understand whether a can be a part of, part of the story. So we talked primarily about this first idea, this idea that you have a patient who may, may not meet bread and death criteria, but the family wishes to donate organs. There's also a second group of, of um patients who may benefit from ECMO or M CS in a different approach. So there are reported cases of premortem cannulation where a patient before withdrawal can uh withdrawal of life supporting therapy may be caned for ECMO specifically. So that if death occurs, the circuit can be restarted to rep perfuse organs and again, minimize that as warm as giving time. There's also a growing um use of postmortem cannulation either peripherally or centrally again to minimize war ischemic time. Um The first in Spain, about half of D CD kidneys are recovered after nother perfusion. In that paradigm, they do peripheral canula and insertion of a intra aortic balloon to that they inflate before we start in the circuit to restrict perfusion to the abdominal organs. But Hoffman and the, the group of Vanderbilt recently published a case series uh demonstrating acceptable graft outcomes for heart recipients that were uh of D CD donors who underwent a period of um central uh accumulation in um N R P. The idea here is doctor was just mentioning is to give the organs both to minimize worm ischemic time and to provide other opportunities for organ assessment before recovery. So, as you can imagine, we're talking about starting people on circuits that look like ECMO circuits um including blood for the brain. There's a lots of lots of potential ethical considerations. I'm not an ethicist. This is a really nice review from the American Journal of Transplant that work walks through some of these issues as I highlighted earlier differences in local protocols, differences in what's acceptably regionally or nationally. We highlighted Spain as a place where there's universal authorization for donation and a and a um a cultural comfort. With these concepts we worry about in situations of premortem cumulation. If patients have the ability to feel pain that they may under um experience discomfort or in the case that organs are not accepted for recovery. Despite this, that they may be undergoing unnecessary procedures for the N R P modalities, blood flow needs to be included to the brain to prevent reanimation and violations of the dead donor rule. This requires active and innovation. Intervention by physicians we may or may not be comfortable with and in situations where that clamp is misapplied or dislodged, we can have full return of circle of circulation. Um uh with real concerns about whether donation can happen, whether or not there should be circulation to the brain. We all have taken care of patients who have no pulse, have no risk reinitiation of circulation, even if it's for the purpose of organ recovery appears to restore life. There's a lot of ethical challenges there, a lot of concerns for families and clinicians at the bedside. What we know about organ donation from ECMO comes from that first group patients who di die on acma and undergo recovery. So this is some local data published from the Gift of Life. Um Donor service area which is southern um New Jersey, uh Delaware and eastern Pennsylvania. This is older data. But one of the few studies that's out there, they followed, they found twe 41 donors in hospitals in the region over the study period. They compared outcomes in kidney donation and liver donation. Their, their rates of transplantation of recovered kidneys were equivalent to those of national averages and similar rates of things like delayed graph function, liver outcomes were less likely to be transplanted. But among organs that were transplanted, they had equal rates of problems like uh graph dysfunction and similar laboratory values. Over the first year, we know from UNOS data that this is collected in some capacity. We found about 200 donors after circulatory death in the national donor data sets that receive some period of ECMO support. These are quite limited. This is only 24 hours before recovery and has tells us nothing about indication for ECMO con con uh configurations for ECMO. But they do did find that with the exception of um small intestine, all organs have been transplanted from these patients. What we know locally from querying our the pen medicine data set is that of our 1700 patients who were supported in a either here or Presbyterian Hospital of the 500, the students, only 25 became organ donors. We have what we don't know here from. This is what that denominator is which of those 5, 21 were, were medically eligible for donation. We don't know what, when, when these were missed opportunities for donation or refusal from families. Our hypothesis here is that we're probably treating these patients differently from we are than we are from other parts of the hospital, other care areas. And so we may be missing opportunities to notify organ procurement organizations. But this is some preliminary work that to try to understand where they're coming from. In our cohort, the majority of uh patients received acma initially for respiratory failure. When we compare some of the really rudimentary measures of of donation success, the majority of our donors were donors after circular death. The median number of organs transplanted per donor in both groups was two compared to local donors. And our those same hospitals uh slightly smaller numbers of organs recovered from each donor. But we did see kidney donation was possible from both D CD and and um DVD donors as was liver, the more common in in donors after brain death and in two donor supported by V V ECMO that with the diagnosis of brain death, successfully donated hearts. We've highlighted some of the outcome. Uncertainty here, concerns about resource utilization especially in small hospitals that already struggle to manage organ donors. Asking them to to start an ECMO program or to use ECMO technology to help support um marginal organs is is um outside of the the um realm of fasul. At the moment, we talked about some of the ethical concerns. And then the public perception that means that we have to be extra rigorous in the science and extra um careful in in our practice. As we move more of our organ donors to donor care units. Like at pen medicine, we have opportunities to use places like that to refine, develop protocols for reperfusion, for organ assessment before removal of organs and using organizations like also to better collect data to understand what happens to the students, whether or not they want to donate for everyone in this room, who's an ex ECMO expert, encourage you to work with your hospitals. Understand what's in your D CD protocols, what's in your brain death protocols to make sure that they're accounting for the potential of patients on ECMO. Um and, and use it and you can use your expertise to help guide those conversations. The last point that I want to make is that the gift of life donor program, which is the regional um organ procurement organization here actually mentions initiation of ACMA as a trigger for notification. Now we put a lot of people in ACMA, we have a lot of reasons for doing that. But if we think about patients that are not expected to survive hospitalization calling early, so that they're aware of these patients is probably best practice. What we hypothesis we're gonna find in looking through our process data is that we're calling for these donors very late. And as you know, when families make the decision to withdraw care, they often want it to be done very quickly before we can do a full assessment or even offer families the opportunity to donate. So I'll conclude by, by stating that ECMO support is not a contra indication to donation. It is possible although not yet known to what extent we can use expansion of pre and postmortem, ECMO and M CS to partially mitigate some of the critical organ shortage, especially if we can combine that with other technologies that have been discussed.