Thank you so much. After that data-heavy presentation, you clearly need some downtime, some relaxation, so we're going to be talking about waves and scuba, but at the same time, I do want to remind you as folks in critical care, we know that we have this innate ability to slow down time. Slow down time and still uphold time as brain, so that's what we're going to talk about. And I'm Neha Dangayaj. I'm a neurointensivist from Mount Sinai, and I'm going to talk about this topic that I'm very passionate about. One of the financial disclosures will relate directly to what I'm going to speak about today. So first, let's just take one step back and think about why neuromonitoring matters in neurocritical care. I'm going to do a little bit of a review of some of these fundamental concepts and then talk to you about scuba. So neuromonitoring matters because we want to uphold time as brain. We know that our patient has suffered from that primary neurological injury. They're at risk of developing secondary neurological injury and systemic complications. So we use all these different tools and in a data-rich environment to really optimize patient-centered outcomes. So now let's go to a case. So here's a patient who's a 55-year-old man who presents with loss of consciousness. His initial NIH Stroke Scale is only 5, and then it worsens to 15. So this is his second CAT scan. And you can all appreciate this subcortical intracerebral hemorrhage. When he presented, his bleed was much smaller. So here's a reminder. One third of our patients are going to have 30% expansion of their hematoma in the first three hours. So there's a lot you can do in the first few hours of a patient's presentation to optimize their outcomes. So keep this picture in mind as we go to some fundamental concepts. You're all familiar with this. This is the Kelly-Monroe Doctrine described over two centuries ago. We know the brain, CSF, blood vessels are all sitting in a tight skull. If something increases, something's got to give. The brain has an innate capacity to compensate for that increase in intracranial pressure by either increasing venous return or increasing the resorption of CSF. So the key principles in management when we're trying to optimize cerebral perfusion pressure, we keep this front and center, CPP is equal to MAP minus ICP. But there's another key concept about cerebral autoregulation and how different therapies, as we move along the ladder and we ask ourselves, is there anything that our surgical friends can help us with as we resuscitate patients and keep ABC front and center, anywhere along this ladder, these therapies and their effect will be dependent upon a couple of additional concepts. You've perhaps seen this waveform. And when you place an invasive ICP monitor, and let's take the example of an external ventricular drain, which is both therapeutic and diagnostic, when you close that system, this is the kind of waveform that you'll see with three Ps, P1, P2, and P3. What are these Ps? So when you look at that correlation between this EVD or invasive ICP monitor-derived waveform, P is the systolic or percussion wave that comes from the transmission of carotid pulsations to the carotid plexus, and you get this P1. P2 is supposed to be this tidal wave that's coming from the ventricular system and the brain parenchyma, and it's supposed to give us an indication of how good our brain's compliance is. And P3 coincides with the diachrotic notch or the closure of the aortic valve. In panel B, you see this, where P2 is higher than P1. In a normal brain, a normal brain that has good compliance, P1 is going to be higher than P2. When P2 becomes higher than P1, it's indicative of poor compliance. Moving from pressure to waves, and from waves to scuba, so let's do a little review of these waves. You all know this, Lundberg A, Lundberg B, Lundberg C waves. But what is critical to remember, Lundberg A, always pathological. These are also called as plateau waves. The ICP remains increased for five, maybe even 20 minutes if you don't intervene. Lundberg B waves, we don't really know what is their clinical significance, but you may see these brief increases in ICP. Lundberg C waves, oscillatory waves that provide some information about normal interactions, which could be interactions between cardiopulmonary status and the brain. And just to show you some wave forms, some pathological wave forms as well. So when you look at the amplitude of these waves, if the amplitude is really high, particularly if you're seeing this peaked P1, or the amplitude is really dampened, it could be indicative of either too much or too little CSF. Post-hemicranial, sometimes you lose that wave form even when you clamp that EVD. What does that mean? It essentially means that that wave form is really, really dampened. If you're seeing a very prominent P1, it could be in those patients who have a very high systolic blood pressure. Very dampened P1, P2, P3 could also be in patients who are hypotensive. Then what about that P2 higher than P1? I told you that the brain has poor compliance, but what does this mean for management? It means that every single thing that you do to the patient, when you lay them flat, when you place an inter-IJ line in them, it's going to lead to an increase in their ICP. We've got to be careful because most brains are going to drain dominantly. That venous return is going to go through their dominant IJ, which ends up being the right IJ. A couple of other concepts before we move on. Intracranial compliance, delta V upon delta P. How much is that pressure going to rise with a change in volume? This is also very time-dependent. When you look at cerebral autoregulation, there are very few vascular beds in the body that can autoregulate. The cerebral arterioles are going to have this capacity to maintain CPP over a very broad range in a brain that has good intracranial compliance. But when you look at this dashed line, you begin to see this linear relationship. As the blood pressure goes up or down, your ICP is also going to go up or down. These are key concepts to keep in mind when you're thinking through that ICP ladder for resuscitating your patient with an intracerebral hemorrhage or any other severe acute brain injury. This is from Nick Martin, ICU one-pager, summarizes a lot of the concepts that we just discussed. Keep it handy. Keep this PDF handy on your phone, particularly if you have a mixed medical-surgical ICU and are not often seeing patients with invasive ICP monitors. So this question about monitoring ICP in patients with intracerebral hemorrhage from this international study from the sign-up ICU investigators, I just want to point your attention to the latter end of this graph, the higher the ICH score, which is indicative of, yes, this patient has a larger volume, they're sicker. Perhaps those patients may benefit more from ICP monitoring. But there's a lot of variability in who gets monitored. So now from WAVES, let's go to SCUBA. The major questions in surgical ICH trials, I mean, this is pretty obvious, right? You're seeing blood. Should we take it out? If we're going to take it out, how should we take it out? If we take this out, what should we do for our patients after we take out the clot? So in the previous presentation, you heard about thrombectomy and you heard about the rapid evolution in literature. Perhaps something like that is going to happen in the intracerebral world. Neurosurgical options, just very, when you look at a broad overview of these neurosurgical options, so a lot of our understanding comes from stitch one and stitch two, open craniotomy for ICH evacuation, stitch one, no difference in outcomes as compared to medical therapy, but there was some signal that told us, okay, perhaps if this low-bar ICH or sub-cortical ICH is within a centimeter of the cortex, maybe those patients will benefit. So stitch two, unfortunately, no difference in outcomes, but there are some indications, for example, a cerebellar ICH. The American Heart Association still has a class one recommendation that these patients should undergo decompression. For minimally invasive techniques, there are lots of different techniques, stereotactic placement of different devices, stereotactic placement of a device, and then dripping TPA through it. I'm going to talk to you about some of those techniques, but before that, just a quick plug, on a case-by-case basis, there are definite patients who are going to need surgical decompression when they have a low-bar ICH. Here's an example of a 60-year-old male who presented with a low-bar ICH, big midline shift, got an EVD and a decompressive hemicranie, and you can see he developed post-stroke epilepsy, but overall good outcome at one year. Taking a step back and looking at this concept of minimally invasive surgery, lots of different techniques, from a technique perspective, a technique agnostic systematic review published in 2018 before MISTI 3 was published shows us that minimally invasive surgery for ICH can work and improve outcomes. So now let me show you a head-to-head comparison of MISTI and SCUBA. The techniques are different. Here are stereotactically guided catheters placed into the hematoma, and TPAs dripped into this hematoma to lyse the clot. In SCUBA, a stereotactically guided sheath is placed, and another device, and these could be different devices, another device is attached to evacuate this clot under irrigation and direct visualization. So first about MISTI, MISTI 3 tells us that, yes, this is a feasible surgical procedure. There's robust clinical experience, and the cannula has a low profile. However, the surgical outcome, the surgical outcome was supposed to be that we have less than 15 cc's or so of that hematoma volume left behind. Unfortunately, only 60% or so patients achieved that surgical outcome. For surgical trial interpretation, we often don't talk about whether that surgical intervention did what it was supposed to do. And perhaps that's one of the reasons why surgery did not work. And here, I'll draw a parallel with those thrombectomy trials, where the first generation of thrombectomy trials showed us, you know, thrombectomy probably doesn't work. And then came the slew of trials after stent retriever. The technique improvement improved outcomes. Is that what's going to happen in the intracerebral hemorrhage world? So MISTI 3, no improvement in functional outcomes, but there was still good news. There was news that if the hematoma, residual hematoma, was less than 15 cc's or so, perhaps those patients can have better outcomes. So do we need better techniques? So with that, I'll talk about SCUBA. There are lots of different inclusion exclusion criteria. It's an ongoing. This is not a randomized controlled clinical trial that I'm showing you. This is more cohort data. So ICH volume more than or equal to 20 cc's, baseline MRS needed to be less than four. So patients who had a relatively good baseline, but fairly generous, unlike MISTI 3, which had a very strict inclusion criteria. So very few patients. They screened lots of patients, and only 3% of those patients underwent the procedure. So when you look at the advantages from this technique, early evacuation potential, so patients can undergo evacuation. When we say time is brain, you don't have to wait for a stability scan, because you can potentially cauterize bleeders under direct visualization, and it's a broader selection criteria. SCUBA was first described. So what does SCUBA stand for? It's stereotactically guided ICH evacuation under visualization using water, using sterile water. The first time when this technique was described in 2018, it didn't have these phases, and I'm going to show you some videos of what this phase 1 and phase 2 looks like. So these patients, just like that acute ischemic stroke paradigm with large vessel occlusion, are taken straight to the angio suite. They may make a pit stop in the ED. They go to the angio suite, get this stereotactically determined burr hole. So where exactly do our endovascular surgeons need to go? And in this burr hole, a stereotactically guided sheath is placed. And to the sheath, different catheters can be attached. Here's an Apollo system, a penumbra artemis. There are other systems that can also be attached. So the first phase of SCUBA, the sheath is positioned 1 to 2 centimeters, not all the way at the bottom of the clot, but somewhere about a centimeter or two distal from the end of the clot. On the right-hand side of the screen, I'm showing you what you can see through that sheath. And you begin to see, this is the tip of the cannula that's evacuating the clot and exploring the depths of that hematoma cavity. So you do this under direct visualization. And this procedure is performed by our endovascular neurosurgeons who are trained in performing this procedure. Several of these slides are courtesy Dr. Christopher Kellner, who both developed the procedure, and is also our ICH program director. So with the proximal cavity reach within the sheath, then this continuous irrigation, more irrigation as that cavity begins to clear up, trying to directly visualize any active bleeders so they can be cauterized under direct visualization. Hence, we don't need to wait for that stability CT so you can perform these procedures early. How did we move from studying a new technique to implementing it within a health system? So the idea was, this is just a map of Manhattan and the rest of New York. Our ICH hospital is on the Upper West Side. So no matter where an ICH is within New York City, we're able to cohort their care to our ICH-focused hospital. So we're using this regionalization of care model that has been so successful for MI, for STEMIs, for thrombectomy. We're using that same paradigm now for 24-7 coverage for intracerebral hemorrhage evacuation. And in this early experience, we described that there was no, we looked at 100 patients of those 190 underwent interhospital transfer. I'm just saying that to highlight the fact that perhaps when you have a treatment that's effective, transferring patients to the sites that are able to provide that treatment in a timely fashion does improve access to care, does help bridge the gap between health care disparities. So time to evacuation. When we say time is brain, is time truly brain for ICH? And Brooke is going to talk to you about all those medical therapies that need to be instituted for blood pressure, for coagulopathy reversal. But when it comes to this technique, if you have a technique that can help you evacuate a clot faster, is that going to lead to better outcomes? So again, single center experience. But what we do see here, the odds of having a worse outcome increase with every hour of delay of evacuation. So the 2022 American Heart Association ICH guidelines have included some guidance on irrespective of what technique of minimally invasive clot evacuation we're referring to, what should be done. So when you look at the class of recommendation, it ranges from 2A to 2B. But to improve mortality, minimally invasive clot evacuation irrespective of the technique has been recommended. And for improving functional outcomes, you could potentially consider it. But it hasn't been shown to improve functional outcomes yet in randomized controlled clinical trials. So back to our case. 55-year-old male presenting with loss of consciousness. Initial NIH stroke scale was low. Rebleed. NIH stroke scale increases. I showed you this slide before. Because he's 55, we also wanted to look for any underlying AVM. So he's in the endovascular suite. So he gets his burr hole. Angiogram shows no AVM stereotactic guidance for where that burr hole needs to go. Scuba. And here's a video from his clot evacuation. This is the sheath. You begin to see the artemis cannula going down, sucking the clot out. And you begin to see a lot of blood. And here Chris mentions while performing the procedure, this is where we need to be careful. We want to continue rapid irrigation and then visualize any active bleeders thereafter by looking at the walls of the cavity. This is the post evacuation head CT. And this is the same patient. This is his wife making a video during one of the scuba workshops. And long-term outcomes from, again, single center. But I want to draw your attention to less than 50 cc residual was seen in 86% patients. As compared to MIS-T3, 60% patients. And 46% of these patients have a good outcome. So as we move the needle in ICH management to uphold time is brain, we really need better techniques to be able to evacuate these clots. And perhaps that acute ischemic stroke paradigm needs to be applied to ICH as well. So we reviewed these core concepts. We went over the Kelly-Munro doctrine, ICP waveform, Lundberg waves, auto-regulation. I spoke to you about minimally invasive ICH evacuation. Appropriate case selection is important. And yes, there is guidance about who and what technique to use in the AHA ICH guidelines. Thank you very much. Thank you.

neuromonitoring

neurocritical care

intracranial pressure monitoring

SCUBA technique

intracerebral hemorrhages