Hi, my name is Dr. Karen Reuter-Rice, and it gives me great pleasure to introduce this session, Can't Get You Out of My Head, Invasive Monitoring in Pediatric Neurocritical Care. It also gives me tremendous pleasure to introduce the speaker, Dr. David Adelson. Dr. David Adelson is really an amazing guy, a great individual, and a brilliant neurosurgeon. But let me tell you a little bit about him and his past. He currently is the director of the Barrow Neurologic Institute at Phoenix Children's Hospital, the Diane and Bruce Halle Endowed Chair for Children's Neuroscience, Chief of Pediatrics Neurosurgery. He received his undergraduate and medical degrees from Columbia University, completed his neurosurgical residency at UCLA in 1993, and a pediatric neurosurgery fellowship at Children's Hospital of Boston, Harvard Medical School in 1994. He then joined the faculty at the University of Pittsburgh, Children's Hospital, Pittsburgh, where he rose to a tenured professor of neurosurgery in the A. Leland Albright Endowed Professorship of Neurosurgery, Pediatric Neurosurgery. He moved to Phoenix Children's Hospital in 2009 and built the Children's Neuroscience Institute, and then assumed the leadership of the renamed Barrow Neurologic Institute at Phoenix Children's Hospital. Under his leadership, Barrow has become a top pediatric neuroscience program in the country. Presently, he is a professor of child health, University of Arizona College of Medicine, Phoenix, professor of neurosurgery at Mayo Clinic and Creighton University, and an adjunct professor in the School of Biological and Health Systems Engineering at Arizona State University. Dr. Adelson is a globally recognized expert in pediatric brain, spine, spinal cord, and peripheral nerve injury. In particular, he has amazing talents in the acute clinical management of traumatic brain-injured children and neurocritical care. He remains active in both clinical and translational laboratory research, where he has been the PI for the NIH-funded Phase II and III clinical trials on hypothermia following severe TBI. He is known also for his work, which has resulted in over 250 publications in referee journals, over 40 book chapters, and as editor of eight books, including The Principles and Practice of Pediatric Neurosurgery in its third edition. Dr. Adelson has been the recipient of multiple awards, including being the first pediatric neurosurgeon to be awarded the highly coveted Herbert Oliver Corona Award, the Nobel Prize of Neurosurgery. It gives me great pleasure to introduce Dr. Dave Adelson. Hi, this is David Adelson. Thank you again to the organizers for including me in this year's Congress. I'm very excited to talk to you about the title, Can't Get You Out of My Head. I'm going to give both the pro and the con debate on invasive monitoring in pediatric neurocritical care. This title is perfect for me because it's the schizophrenia of how I feel with regards to invasive monitoring, and so I do feel I could give both the pro and the con, and that's what I hope to impart to you today. I do have a disclosure. I do work with Medtronic as a consultant, but there will be no references specifically to any of their products in this talk. As many of you know, trauma and traumatic brain injury unfortunately still remain the leading cause of death and disability in children in the United States and around the world. Other types of neural injury are also very common, and in many instances, because we don't monitor, may not even be detected. We know that mortality from trauma and particularly traumatic brain injuries still remain greater than all other pediatric diseases combined, and unfortunately most of how we apply our protocols is really based on single institution series, a number of clinical trials, and cohorts, but the reality is that there's very, very few really standardized studies that have been out there, and really because of the conflict that we often see in these different studies, there's really little new or unique drugs or therapies that have been introduced to improve outcome. We know that the brain is a very complex organ, and brain injury is a complex disease, and it's really complicated at multiple levels of differences, but unfortunately our practice today has depended on a single or minimally invasive monitoring parameter, and it's these defined parameters that unfortunately oftentimes don't take into account individual variation, and I think this is where we start to get this schizophrenia as should we invasively monitor or should we not. As I mentioned, we have a number of clinical trials and a multitude of studies, but these studies have often been conflicting, and as a result we've not been able to define the optimal approach, and so lastly for a complex organ like the brain and a complex disease like TBI, I do think that we need to have new strategies developed, and I think that we need to really take a look at how we do things and not do things the same way. So obviously doing things the same way over and over and expecting a different outcome really is the definition of insanity, and that's the reason for a pro-con debate here today. Key takeaway points that I'd like to start off with is that we know that aggressive early evidence-based protocols do indeed lower morbidity and mortality. If we take the 30,000-foot view, our goal with therapy is really trying to avoid further insults to the brain after that primary injury and really to be able to lessen the secondary injury mechanisms. The only way in the future that we will be able to do that will be to identify, then measure, and then be able to show how treatment of acute or ongoing brain injury is occurring and be able to move forward with those in the future. So having said that, there are a number of different challenges and really the challenges are that we see a lot of different pathologies when it comes to severe traumatic brain injury. In this slide from Jeff Manley, it's a classic slide at this point, but the reality is that we've often been categorizing severe traumatic brain injury, here a patient with a Glasgow Coma Score of 4, with all these different pathologies, they're not the same patient. So the reality is that traumatic brain injury is not necessarily one disease. Again, we wouldn't categorize in this day and age a patient with a brain tumor as just being a patient with a brain tumor. So we need to start to look at different parameters by which we are dealing with patients who have a traumatic brain injury. Indeed, if we add in the complexity of the aging brain, so looking at a pediatric brain and in this instance non-accidental trauma, we need to start to look at not just the pathophysiology, but we need to start to look at what is the differences of the brain at different ages and how that might impact treatment and or care of these patients. So the first is, is how best should we be categorizing injury and outcome? And so can we really just depend on the Glasgow Coma Score? Should our examination be much more complex? And there are a number of different ways that we do that. We measure just on our neurologic exam alone a multitude of different parameters. Should we have other diagnostic measures including imaging or biomarkers or neurophysiology? Do we have other measures that might be able to tell us prognosis? Can we categorize things by which we would be applying differences in management? And then ultimately how are we measuring outcome and how best should we be measuring outcome and how might those differ from patient to patient? So if indeed we add this whole level of complexity to categorizing and looking at outcomes for patients, we then have to start to think about how do we identify and measure those second insults and those secondary injury mechanisms? Well our present day therapy has been ICP directed, so an invasive monitor either a wire or a catheter or an external ventricular drain has been used which is an invasive monitor to measure intracranial pressure. And so the question comes up, should I place an ICP monitor? And up to today for the most part if a patient meets criteria of a severe traumatic brain injury, a Glasgow Coma score of 8, most people and most algorithms have been recommending the placement of an ICP monitor and that's really based on this concept that treating traumatic brain injury without knowing the ICP would be like treating diabetes without knowing the serum glucose. This is our present day approach toward the management of these patients. But this begs the question, what exactly are we obtaining from this invasive monitor? And so when one questions the use of an invasive monitor, so the con debate under this is what information is it providing to us and will it provide us further information that would be useful in any particular patient? Who optimally should get it? Well we know that there are some instances based on imaging or based on exam where maybe we wouldn't necessarily need an invasive monitor. Maybe a patient with DAI do they absolutely need an invasive monitor. What exactly are we measuring and with that measurement are we going to be able to utilize that monitor in a useful way that doesn't add further insult or injury? And then what is the outcome that we're trying to obtain from that measure? And so again these are the questions that we have with regards to ICP or invasive monitoring that still remain to this day and so as a result this is what adds the complexity to these different questions. Well suffice it to say that contemporary management there are three ways that we try to mitigate or improve outcome in patients. The first is to prevent the injury, so prevent the primary mechanism or mitigate that injury with something like a helmet or seat belts or something along those lines. We have some evidence based protocols in order to try to optimize care but these are ICP directed in many instances and we also have some strategies for rehabilitation in order to take that chronically injured brain and now try to get an improved recovery. So any of these different strategies will lead to an improvement in outcome, but if we apply this toward the acute management of brain injury we know that the impact or the primary insult is what's called the primary mechanism and that primary mechanism leads to the primary injury. That primary injury of the brain then leads to a cascade of events that are called the secondary mechanisms and those secondary mechanisms lead to the secondary injury that we eventually see. If we now add insult to injury these then worsen those secondary mechanisms and then this leads to the worsened secondary injury. So if indeed we're going to mitigate the primary mechanisms then we hopefully lessen the primary injury. If we can mitigate the second insult, so decrease the incidents or occasions of hypoxia or hypotension, hopefully we can decrease the secondary mechanisms and then if we can reduce the secondary injury mechanisms then hopefully we can reduce the overall brain injury. That's ultimately what our management involves. It involves decreasing or avoiding the second insults like hypoxia or hypotension, treating intracranial hypertension and we've got a number of different therapies that have been reiterated over the last number of years, as well as we have surgeries in order to avoid a second insult like an epidural hematoma or a decompressive craniectomy for the secondary injury mechanisms. So in those instances as I mentioned our primary approach toward management is ICP and CPP directed and we have definitions for those and we know about intracranial pressure, but CPP is basically a calculated parameter based on the mean arterial pressure minus the intracranial pressure. So the ways that we would optimize cerebral perfusion pressure would be to minimize hypotension, so keeping blood pressure in a normal range, as well as to minimize intracranial hypertension. Now unfortunately our definition of intracranial hypertension differs particularly with regards to age and there are a number of different parameters that have been used and suggested, but these number of different parameters vary because we don't have a really a great understanding of the particular optimal approach for patients across the age spectrum. So should we be treating the infant the same as the adolescent? I would argue not, and so as a result we do have these very vague and undefined ways that we should be approaching things. Well in the old edition of the guidelines there was this very linear approach toward care. This is the first tier therapies and the second tier therapies and what we've done with the more recent iteration of the guidelines now with the third edition most recently in March of 2019 is now start to add complexity to this algorithm of our understanding. And so we do have those first tier therapies and again I won't reiterate those here per se, but suffice it to say is that new or different pathways have been introduced into the clinical algorithm in order to really provide a more rich approach toward our understanding of what indeed is going on and apply those to modern therapy. So we have baseline care which is again to try to avoid second insults. We have a surgery pathway as needed for those patients that require surgical intervention. We do have an ICPP or CPP therapy pathway as well as that there is a herniation pathway. So what should we be doing in an emergent situation such as herniation? And then in those instances where one is using brain oxygen therapy one could then be applying, and this again is an invasive monitor, a number of different approaches toward management for those patients. And so in the more modern day algorithm you can see it's not just the linear ICPP, CPP pathway, but rather a much more rich approach given that we know that the brain injury and its results really do require a much richer approach toward our understanding. And indeed the second tier therapies, again there's a multitude of different opportunities to approach these different treatments and again different pathways depending on what exactly you're dealing with and so as a result this allows for a more individualized variation. But again to highlight advanced or additional neuromonitoring is recommended in those instances where patients we don't have an understanding of what's going on and that this may help to better understand what's real-time therapy potential for those different patient populations. Well suffice to say that I believe that we need a much broader and much more complex future approach to neurocritical care and again a great slide by Jeff Manley who pointed out many years ago that there is a lot of complex care being done, complex monitoring being done in the CVICU and as a result you've got cardiac physiology, you've got biomarkers, serum biomarkers, you've got electrophysiology, you've got neuroimaging and as a result you've got about 200 drugs that are being utilized in the CVICU in order to manage the heart and particularly the injured heart or compromised heart in those instances. In the neuroICU unfortunately if we've only got two parameters, MAP, ICP and a calculated CPP, well maybe we are what we have gotten here and that's we have only four basic drugs that we use despite the fact that I introduced this otherwise new complexity and maybe we've got surgical therapy as being a fifth approach or intervention for these patients. I would argue the reason that we have such few drugs and interventions is that our current neurologic monitoring is quite limited. Well how so? If so if we look at what our present day ICU monitoring is and if you go from basic critical care unit to basic critical care unit and look at the patients in those populations, well we've got some physiology and maybe we've got some serum markers here of PaCO2 and PaO2 and we've got some invasive monitoring, but that's about it and as a result that's a very limited approach. There are a lot of available neurologic monitors out there, some of which are invasive, some of which are non-invasive, but unfortunately they are very underutilized and we have to now start to ask ourselves well we've got a lot of different ways of looking at the brain in real time, why aren't we utilizing these neurologic monitors that would give us further answers to the complexity of the brain injury. Well we can all agree that our goals really when it comes to neurocritical care is to create an environment of neurorecovery and I think that the challenges of creating that environment for neurorecovery are a number of different challenges and these include understanding what's going on with the injured brain in real time. So we need to be able to understand the physiology and the pathophysiology in a rapid enough way where we could then be able to introduce new interventions or therapies. We have to be able to develop the capability to measure these events, so we have to be able to identify patients who are suffering second insults in real time as well as those secondary mechanisms of injury. By doing so we'd be able to then prevent those insults and injuries from occurring hopefully in advance of them occurring and so if we had the ability to be prognostic or predictive we would be able to indeed intervene before those insults or injuries started to occur and then we have to also measure whether our treatments or our interventions are working and the only way to do that is to be able to have different measures and modalities of monitoring. Well I do believe that this exists. Here's an example of multimodal monitoring. This includes invasive monitoring as well as a whole series of non-invasive monitors and so this is really what I see as the future toward a precision medicine approach to neurocritical care and the only way that we can achieve that is if indeed we have increased real time and integrated information into our decision making. This requires us to bring together our available and useful technologies to bear in every single one of our patients. Of course it's still unclear as to the utility or relationship between these modalities but because we don't even measure them, we don't even understand their utilization or their utility we don't yet have ways for us to move forward in this regard. I do think that our future is also going to require increased data analytics. So how do we use all of this information? Wow we've got all these monitors but then how do we utilize that information in order for us to be able to change our perspective and change those perspectives of those around us to be able to target specific problems, but not just specific problems but specific problems in each individual patient. Then I think we need to explore the potential for how is all of this data, this big data approach and potentially using artificial intelligence in neurocritical care really going to be able to get us to that end point of improved outcomes. Well the question as I raised earlier was should I use invasive monitoring or not is the same as the questions you should be using when should I use advanced monitoring or not. We need to ask all of these questions for everything that we would like to introduce into the ICU for a given patient. So with ICP monitoring we know that we make decisions based on whether the pressure is high or low but whether that pressure is high or low or not still remains a question. So should we be treating this or not? All of these raise further questions about what we should be doing now or in the future. The reason that this comes up is of course the work by Randy Chestnut who showed whether ICP monitoring as a whole would be any different than if we just maximally treated every patient. But the reality is that there didn't seem to be a big difference, but again were we applying monitoring for every single patient and should we be applying monitoring in all of those different populations? Well as I mentioned if we only stuck to thresholds of ICP there really isn't a common thread if we had all of those different pathologies. So we wouldn't for example do radiation for every single brain tumor because now as we define differences between brain tumors we now start to define different parameters. So I would argue that there's more to ICP monitoring than just following a threshold of ICP or an estimation of cerebral perfusion pressure. We can get a whole series of other types of parameters including cerebral pressure reactivity, reactivity index, further calculations and correlations that then allow us to then start to look at ICP waveforms, to start to look at autoregulation and so now there's more to ICP monitoring than just measuring a number high or low. We know that with waveforms we know there's issues of compliance and decompensation. We can start to tease out differences in compliance and know when there's potential for deterioration in those patients. We know that these different waves can be calculated and with advanced analytics better understood and create prognosis for these different parameters and as a result now we add a whole new series of complexity to our understanding of just ICP and CPP monitoring. When we apply these different parameters we can now start to think about prognosis and start to apply these parameters in an algorithm, so identifying the optimization of cerebral perfusion pressure. This can then give us very easy scales to follow to look at green, yellow, red for example and know when a patient is at significant risk for brain injury and further brain insult, when a patient is at risk for deteriorating when we see scales changing, as well as when we've got them in the optimal milieu or the optimal environment for recovery. If we indeed took this more individualized approach, we've got ICP and CPP, it's not just about the numbers high or low. We can start to add other invasive monitors like brain oxygen. Now we start to have differences in our management, so a patient with high ICP but normal brain oxygen maybe that's not a patient that we would treat right away, but a patient who has low ICP with very low brain oxygen maybe showing ischemia, well that might be an instance where indeed we may decide to intervene or not because we know that the brain evolves over time in different types of injury and different pathophysiologies. Initially if a patient's ICP is high and their brain oxygen is low and we lower ICP and brain oxygen gets better, well that's indeed where pressure has had a significant impact on perfusion. But when they start to go in parallel, so here ICP and brain oxygen go up in tandem, now you're dealing with potentially hyperemia, well this would be a different approach to treatment. So indeed if you've got ICP high and low and now you add different parameters, now you have different points in the decision tree that allow you a much more rich understanding of what's going on pathophysiologically, that then allows you to have different modalities by which you would be applying that question of treat or not treat. So if we add then non-invasive monitors and we see in this instance a patient whose ICP was going pretty much flat but their TCDs were showing an increase in velocity. Here was a patient where we gave treatment because when we took this patient for angiography we indeed saw cerebral vasospasm, we gave the intraarterial verapamil and here we gave a treatment that's not listed in the guidelines and indeed was able to treat in this particular patient their cerebral vascular vasospasm and indeed improve their perfusion of their brain. So in this instance ICP, CPP were normal, brain oxygen had been going down, TCDs were going up and in this instance we were able to intervene and improve outcome. So indeed we can start to think of things in a much more rich way here in a 2D way. If we were to start to think about a much more complex brain in a 3D way and so start to now understand further complexity to what we're dealing with here, if we now add time to this element, the 4D element, now we're starting to go from being hourly ICP measures to minutes, to seconds, to maybe milliseconds or even more, a thousand hertz if we're looking at EEG and looking at high frequency oscillations, we could be seeing a patient who might be having subclinical seizures. So as a result we now add a whole new complexity to our clinical decision support and this then allows us to enter into the matrix and start to really tease out much more rich understanding of the brain in real time. So our goals now have to be how do we take this whole chaos of different parameters and information, take all that confusion and integrate that into our present day ICU and I would argue that it's an iterative process. We aren't there yet. But if we take that approach toward taking all of those different parameters, being able to detect early insults and injury, start to develop novel therapies, to take new parameters and new biomarkers and create that iterative process and then apply that back into the laboratory and bring those ideas and models back into the clinical realm, then we're going to better be able to understand what's going on with the brain in real time. And so our goals, and again this is some great work by my colleague Brian Apabu, where our goal is to take all of these different parameters that when you look at it, it makes your eyes cross, it's all a bunch of chaos and confusion, but the next step has to be a way for us to integrate these and the way to do that is through an integrated ICU neuromonitoring system and to do that we need to make it user friendly, we need to make it real time, we need the ability to do data mining and understand what's going on, but also develop that event monitoring and in some ways you can see that in today's availability, the ability to see all of this information in real time and then start to introduce how they all relate and how do we bring this going forward. So I would argue that the future of data analytics and neurocritical care really does require us to take all of these different informational parameters and their relationships and pull these together into what's going on with the injured brain in real time. So I would argue that the future is here, that data analytics and big medical data sets are available to us. We know that this exists and truly it improves our understanding by improving our data with new technologies, being able to develop new algorithms with this new information, but clearly we have to ensure data security and privacy. This is a present day modern ICU. These are the types of measures that we can be looking at in patients and these are the types of things that we add to financial systems. Now we need to apply these same type of monitors and parameters to our ICU. So going back to this previous slide, again I do think that this is the past. Our future has to be our ability to measure all of these different parameters and this will give us a limitless potential for future drugs and future interventions for this patient population. So indeed the future will be an individualized technology driven and data driven future for neurocritical care. It will have to be real time and whether it's invasive or less invasive or non-invasive, it has to be driven by the mechanisms. We have to know why is it that we're measuring what we're measuring, who best to measure in those patients, and as a result we'll get plenty of data and then with that data we need to develop the relationships between that data and then look at how does the therapies drive this in the future. Having said that, we need to add more weight to this side of the seesaw. We need to really be much more aggressive because in all of these different disciplines a more individualized, personalized approach to medicine is being applied and we now need to do this in traumatic brain injury and particularly pediatric traumatic brain injury. So in closing, clearly our aggressive and early evidence-based progetocols have lowered morbidity and mortality but it is based only on invasive monitoring. What our therapies in the future, as they are today, will be to avoid second insults and lessen secondary injury, but the future is that we have to be able to measure those in real time in an integrated way so that we can apply them in a much more futuristic and individualized approach toward each patient. This will require much more computational data analytics and further complex treatment algorithms and our future therapies are going to depend on our ability to understand what those mechanisms are, be able to measure those in real time, be able to understand their relationships between each other, and then be able to apply our novel therapies and then measure what the effect is of those novel therapies in the future. So with that I thank you for your attention and again appreciate the invitation to speak with you today. Thank you. Well, good morning or good afternoon, everyone, depending on where you are in this part of the world. We have a number of questions here for Dr. Adelson. And let me first start by saying thank you, Dave, for such an incredible discussion, both the pro and the con. And I love the schizophrenic piece because I think it's really very true for neural ICU monitoring right now. But let me jump to the first question by Dr. Jose Diaz Gomez. He's the chief of cardiothoracic surgery, MCS, and transplant critical care at Baylor College of Medicine. And he'd like to know, are you aware of any integration of critical care, ultrasonography, including brain ultrasound, and conventional brain monitoring in real time for prevention of secondary brain injury? Well, that's a wonderful question. Again, a lot of these technologies are being utilized in sort of one-off ways. And so I think that when it comes to our specific monitors or specific diagnostic measures or things along those lines being widely used, no. I think it's really when there's somebody who has a particular interest or has a drive to understand better a particular aspect of the physiology or the pathophysiology, then that's when we start to see the literature in this area, the data. And I think it's really a matter of incorporating the different subspecialties together in order to try to come up with clinical algorithms or pathways in this regard. With regards to the secondary injury mechanisms, we don't do a lot of measuring. And this comes down to, are we measuring, for example, excitotoxicity, which is a very common thing that we have known about in animal models and things like that. But we don't routinely monitor them. There has been some work with microdialysis, for example. But we're not really seeing a lot of the utilization of that in our present day management. There isn't a lot of literature. There's a few centers. What's prohibiting us? And I think it takes it back to the questions that I posed is, what information are we getting from it? When should we apply it? Which patients should we be using it in? And I think those are the things that add to the schizophrenia. Well, wonderful. So I'll follow up with his second part of this question, which is, what is your opinion about microdialysis as a monitor? And does it have a specific role at this time? And if so, which setting? Again, I think that we, as I posited in my talk, is that we have a lot of neuromonitoring capability, but not a lot of literature as to its utility or its benefit. Part of my goal with the talk was to raise awareness that there's a lot of potential monitors out there. There's a lot of different things that we could and maybe should be measuring, but we don't have the literature yet. And so do I believe that excitotoxicity is an important mechanism after traumatic brain injury or stroke or other types of brain injury? Absolutely. How best to measure that? That's an invasive monitor. And so again, we have to weigh the risk benefit. Are we able to now start to measure things with excitotoxicity? Let's say via serum biomarkers. Might that be a better approach than an invasive monitor in the brain? That I'm not sure yet. And that's where we really do need further clinical studies and further research in this area, which again, creates that cycle of iterative questions that we need to raise. What are the mechanisms that are important? How do we test that in the laboratory? How do we then now bring that back to the clinical setting? So again, bedside to bench to bedside with a number of questions in between. Great. So let me jump to Leah Lowry's question. She's the director for the Division of Pediatric Critical Care, SSM Cardinal Glenn Children's Medical Center. And her question essentially says, hang on. I can't get rid of her name for some reason. My screen has frozen. OK. So essentially, she wanted to know, could you talk a little bit about the role of PbO2 monitoring? And let me see if I can refresh and get the rest of her question. But maybe you could take it from there. Well, I'll start with the PbO2. So as I described in my talk, I do think that PbO2 monitoring is necessary. Now, this gets back to patient by patient. Are you expecting ischemia? Are you expecting problems? I don't know if we can predict that right now. And that's the reason that I have been the one part of me that says we should be invasively monitoring everybody. And then if they don't need it, then remove it. Then there's the other part that says, can we really better judge which patients are not likely to need it? And so do we want to add that extra risk with minimal potential benefit? So those are the devil and angel on each one of my shoulders. So I do think PbO2 monitoring is important. I do do invasive PbO2 monitoring if I'm going to do invasive ICP monitoring. If I'm not sure if there's a DAI patient, GCS at 8, I want to see if they're going to wake up, I would still do PbO2 monitoring. But I use near-infrared spectroscopy. So it's a non-invasive monitor. It gives a relative number. I like to see that it is responsive with different management. So if we raise the FiO2 or if we raise the CO2, do we start to see appropriate responses from those maneuvers? Well, then I feel more comfortable with the non-invasive approach. If I'm getting sort of contradictory information, then the invasive monitoring may become more important, and especially if I'm deciding to use invasive monitoring on the whole. So I've been a little, I would, compared to my old self or younger self, I'm a lot less aggressive on invasive monitoring. But I'm doing that on judgment of, again, looking at the imaging, looking at the mechanism, looking at what I think may be a patient that's more likely to recover quicker. And so then I just maximally treat medically without the invasive monitoring. So that's the approach that I've taken. So the second part to her question was really, PbO2 is a first-line monitor in severe TBI, and do you have a protocol that you use at your center? So as I described, we use the non-invasive, the near-infrared in every patient in our neurocritical care. And that's really to give us and show us whether they're oxygening well. And again, it's a relative number to when they first present. So it can be skewed. But you're also comparing it to somatic oxygenation. And so looking at those numbers and looking at trends in those instances, I think we do monitor those. If I'm going to do invasive monitoring, I tend to do a significant amount of invasive monitoring. So I'll do invasive ICP, invasive PbO2, and invasive EEG along with all of our monitoring in order to do that. And that's really been championed by Brian Apavu, who I mentioned in my talk. He's really been the one helping push this in our patients. And as I mentioned, we've really expanded from, it's not just about traumatic brain injury, but also stroke and status. So we're monitoring PbO2 either invasively or non-invasively, I'm sorry, non-invasively in everybody, invasively in those patients where we think we need the extra information or we're getting contradictory information. Same with the EEG, we monitor it pretty much in most of our neurocritical care patients because we're looking for subclinical seizures and whether they need to be treated or not, whether it's stroke or trauma. And then of course, in all patients who are worried about status. Thanks, Dave. So I'm gonna follow up with a question from Dr. Lori Schutter from Pittsburgh's Critical Care. She wanted to know, do you use FiO2, MAPS, or CO2 challenges to PbO2 data to help guide individualized patient care? So, yes, we do, Lori. Thanks for the question. So we do use those challenges. I tend to err more on the oxygen side because I think a lot of our goals are to avoid those second insults. So let's say that they're oxygenation and let's say we're using NEARS and it starts to kind of get that dwindly drift, then we'll try challenges to see that we're appropriately monitoring it. Again, we're dealing with not just the, yes, the neuro is important, but we're also dealing with the critical care aspects. And so we very much are looking at the issues of, what's the pulmonary function, what's cardiac function. We're putting this all together in order for us to understand how this might be impacting the brain, particularly a brain that's at risk or is potentially gonna suffer a second insult. We don't want hypoxia to happen. We don't want a second insult to happen. We don't want ischemia to happen. So monitoring that, if we start to see these dwindles and we're starting to see a drift off in the NEARS or in the PbO2, those are both instances where we have to figure out the etiology of that. Is it pulmonary based? Is it brain based? And so I think that we need to be looking at all the picture and that's why it's so important it's not just about the somatic and worry about the brain later. It's about the somatic and the brain and everything together. How are they all interrelating so that we really ultimately create that environment for recovery, that milieu for avoiding second insults. So the hypoxia, hypotension, normothermia, so we don't want them to get hyperthermic. And then similarly, we want, that'll potentially lessen our secondary insults. And those come from those mechanisms that get out of control and we're trying to avoid that. We're trying to avoid status or subclinical seizures, avoiding the things that would worsen, excitotoxicity or inflammation or things. So I'm gonna circle back. Dr. Diaz Gomez had a couple of questions. One he had was, describe new developments in the prevention of secondary brain injury. And then he also wants to know your opinion about the evolving bedside EEG monitoring in neurocritically ill patients interpreted by general intensivist. You have any thoughts on that? So new developments to prevent secondary injury and then the EEG. Yeah, so with regards to secondary injury, I don't think we do a good job and I don't think we're really measuring those things. So I'm alluding back to the microdialysis, for example, would be able to pick up some biochemistry changes, lactate increases, for example, excitotoxicity. So those would be instances where we might be able to pick up this early ischemia or pick up, you know, excitotoxic levels of our excitatory amino acids or other markers. And I don't think that we adequately measure secondary mechanisms. Now, second insults, those are things that I think we should be able to readily measure right now. And those second insults, as I said in my previous answer, hypoxia, we should be able to maintain normoxia throughout their stay in the ICU. We should be able to maintain normothermia, if not slightly mild hypothermia throughout their hospitalization. And whether that's through, and that's just basic temperature regulation. We should be able to avoid hypotension. So we know that even just those three parameters, if we took a meticulous adherence to the detail, I mean, I cannot tell you how many times I've, there's plenty of my colleagues who will echo that I've said this over and over and over and over again, is the fact is that I would sign out at seven or 8 p.m. and everything would look great. And then I'd come back and the child was, you know, 40 overnight and hypotensive and hypoxia and no one really got a call. And you're just like pulling your hair out. You see, I pulled all my hair out already, you know, from this. And this was really the necessity of trying to just be meticulous in that. And if we can avoid, and then we start to recognize that, for example, infants and very young children, well, going now into your second point, I do think EEG is very, very important. And that's because there are a reasonably high percentage of children, you know, maybe 20, 25%, particularly those under the age of one, where it could actually be upwards of 80 or 90%, suffer subclinical seizures. Subclinical seizures are a secondary mechanism, but also a second insult. As I said, it becomes a bad cycle. And so when now you create a hypermetabolic state, when you've already got a compromised brain, now you're creating ischemia, now you're creating further insults, now you're creating worsening mechanisms. And so by detecting those, so, I mean, if you go based on the guidelines and, you know, wow, maybe we treat, and there's even some optional recommendation that we should use antiepileptic medication, well, would you not give antiepileptic medication if you saw a patient in subclinical status? I would argue, yes, you would, but you don't know it if they're in subclinical status. So until we measure it, we don't know that those insults are occurring. And so we have to get our technologies to start to measure those secondary mechanisms. And that's where I sort of say EEG is an important facet of that. So we're now detecting using invasive EEG monitoring in a certain subset of patients that surface EEG is not picking up seizures in patients that are having seizures when we measure them with depth electrodes or surface electrodes, you know, in this patient population. So if that's occurring, and we're not measuring it even from surface EEG, well, then you can start to recognize what are the patients that we should be potentially doing invasive monitoring. So I do think EEG is important. I think it's important, particularly if the insult is large enough, if there's contusions, if there's infarcts, I think those are prime patients that we should do at a minimum surface EEG. And if we're gonna go to invasive monitoring, then we should also consider depth electrodes in those patients as well. I hope that answered your question. All right, so I'm just gonna scroll up here because the questions I'm posing to you are all being voted on by our participants. And so Dr. Wolf, he's at Vanderbilt University, assistant professor, had a question. He said, excellent talk. Thank you. Regarding advanced computer indices, is there a particular tool that is not routinely used in pediatric neurocritical care that should be implemented as standard of care at all centers today? Or currently, should there be tools and platforms like PRX and Moberg be used primarily in the context of research? That's a great question. So again, I think I prefaced my talk so much that I'm a zealot. And so I'm very much, I would say that I am a super pro for advanced monitoring. Now the pro and the con about invasive monitoring, that one I'm still a little schizophrenic on. And that one again is one that I think we need to learn much more. So when it comes to monitoring, if you ask me, should we use more advanced monitoring? My answer is absolutely yes. Should we be doing PRX? Should we be doing all those other ICP, CPP related relative indices and measures and things? Absolutely. Do I know what they mean yet? No. And that's really where I think that we need to have larger consortium with larger amounts of data and be able to put these together so that we can take the PRX platform or some of these multimodal platforms and improve them. So we're really at the absolute infancy of this very, very important area. And we should be putting forward advanced data analytics for every patient until we understand which patients are best gonna benefit. So similar to my paradigm that I was showing, the more advanced monitoring we have, the richer our understanding of the complex associations and relationships and problems over time that the brain is suffering after a stroke or after a TBI or when they're in status epilepticus. We don't know those right now. And so I think there's a lot of exciting research in this area, but what I don't see is research adding monitoring. It's really the research is how do the different parameters interrelate? So again, going back to just a simple two probe or two parameter analysis, if we looked at just ICP and PbO2, you can see you're starting to create a very rich understanding. Is that brain with the high ICP ischemic or not? Is that brain that's hyperemic, is that hyperemia the cause of their ICP elevation or not? There are different ways to treat that. There's different ways to appreciate that. I don't think we know the answers to those. If you have a patient with a normal ICP and they're hyperemic, maybe a little bit of hyperventilation, maybe you can go two to 32 instead of a 35, maybe that alleviates some of that hyperemia. Maybe that alleviates some of the vasogenic edema. Well, then you're making a difference, but we don't have yet the science to back that up. And I think we need to be doing much more research, but I don't see it as research as in we need to take that back to the lab. Research or understanding that we could be applying right now in our clinical setting. And that's what I've learned over the last, hate to say 20, 30 years is it's not just, if we simplify things down to a yes, no, I think we're really underselling the complexity of the brain and its response to injury. Great, thank you. So Dr. Shirley Chang, actually the Division Chief for Neurocritical Care at Duke University has a question. She says, thank you for the great lecture, Dr. Adelson. You have given some great thoughts about future advances that are needed. What are your current thoughts of EVD first versus ICP-LICOX monitoring? Some neurosurgeons prefer CSF diversion in TBI immediately. And in this circumstance, if left open to drain, have limited continuous waveform monitoring. So if I put in an EVD, I do do continuous drainage and I do put in an ICP monitor wire in addition to the EVD for that exact reason. I don't put EVDs in everybody. So I'm a little bit on, if there's a lot of subarachnoid hemorrhage, interventricular hemorrhage, large contusions, I'll go ahead and put the EVD in and I'll put the ICP wire in, same side, same place. PbO2, I tend to put not in the penumbra, I tend to put it on the contralateral side. And that's really just a function of the clinical algorithm that I've used. I'm not completely confident that we know exactly where we're putting the monitor sometimes, excuse me, when it comes to trying to target a penumbra. And so I'm a little mixed on that and I guess I'd have to be sort of proven that way. Going back again, as I said, I've become more conservative in that I don't put EVDs and ICPs in every GCS of eight or less. I know that that's probably an anathema for some, but I am convinced that not every patient meets the criteria. I think we have to get better at deciding what that criteria is, but I tend to get a lot of early imaging and take a look and see. And there have been a lot of patients that I've put in wires where I kind of predicted that I wouldn't have a problem. And they woke up in a reasonable amount of time where their ICPs were not a problem and I removed the wire. I've also had situations where people did put in monitors and not myself, but we did have a large bleed. And so I have to recognize the risk benefit. And so that's why I'm a little more measured in when and what we do. I think we need more information and I don't know if it's the right thing. I think I've swung both ways over the years. Thanks. Well, Dave, I'm gonna ask the last question here by Dr. Beth Taylor, who's a research scientist at Barnes-Jewish Hospital. And she said, current ICP numbers often halt ancillary therapies like PT, feeding tube placements, dressing changes, whatever. Will new real-time monitoring help us be able to, let's see, be more immediate in their care and not delay care as we often have to? And I'm gonna let you wrap that up with the last 20 seconds. All right, so I'll say that I really feel that those feeding tube for nutrition is important. So I think it needs to go in. I think certain amount of PT and OT in the ICU is good for the patient. But again, ICP is a limited parameter that we have to worry about. You know, we have to gauge that with, you know, if the ICP is going to 30 or 40, probably not a good idea. But if it's going up into the 20s and we can, you know, pre-treat and manage it medically appropriately, and it's not affecting the brain oxygen at the same time, then, you know, I would use that as, that ICP alone is not the way we should go. It should be, what does the total picture look like? I hope that answered it quickly enough. You did, and I think we're out of time. So thank you so much, Dr. Adelson. Thank you all. We'll see y'all later. I appreciate the invite. Thank you.

neurosurgeon

Barrow Neurologic Institute

pediatric neurocritical care

traumatic brain injury

intracranial pressure

cerebral perfusion pressure

brain oxygen monitoring

electroencephalography

secondary brain injury

personalized approach