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And also, as of now, it's time for the session. May not permit the panel to field every single question, but we'll just leave it up to them as far as fielding it out for the session. And with that, I'll hand it off to Shane, and if you'd like to get started, feel free. Wonderful. Thank you so much, and thank you all for coming, and we definitely do want to engage with you all. Please ask questions. We'll try to keep an eye on the chat, but our plan is to hopefully have this take 40 to 45 minutes to leave time for questions at the end. I feel like this is a very interesting topic and definitely can really shift and change practices, so we want to make sure that we answer any questions that we can over here. So again, thank you all for coming. This is Breathtaking Advances, the Utility of Ultrasound in Spinal Cord Injury Ventilator Management. This is a collaboration between the spinal cord injury community, as well as the neuromuscular electrodiagnostics communities, so we're really excited to be able to do this together. We don't have any disclosures. And your panel, I'll let everyone go ahead and introduce themselves. We can start at the top and go counterclockwise. Hi, everyone. Dr. Adui. Hi. Good morning. Nice to meet you. I'm Dr. Adui. Nice to meet you. I'm here at the Schley-Ryan Ability Lab in Chicago, Illinois, and I am just a neuromuscular electrodiagnostic specialist, and actually one of my particular area of interest is neuromuscular complications in the spinal cord injury population. Counterclockwise is me. I'm Colin Franz. I'm also a neuromuscular doctor who's really interested in ultrasound, the diaphragm, and electrodiagnostics related to spinal cord injury care, upper extremity, and breathing. And we've done some work at our hospital and been getting a bit more interested both in our clinical research and our preclinical research on restoring diaphragm muscle function with nerve transfers and with diaphragm pacers. All right. I'm Natasha Bhatia. I'm a physician at Schley-Ryan Ability Lab as well. I specialize in neurorecapsy, primarily spinal cord injury, stroke. And as far as research interest, as you'll hear about this hour, looking at diaphragm ultrasound and how that impacts ventilator weaning after spinal cord injury. I'm Shane Stone. I'm a physician at UC Davis Health, although was at Schley-Ryan Ability Lab for my co-panelists, which is how I got to know them and learn a little bit about what I'm doing, managing all different types of things here, trying to expand to do some pulmonary research here as well. I'll share, if time permits, some of my previous work and maybe talk about some of my upcoming projects as well. Let's go ahead and keep going. So we have four main objectives for today. We want to talk about the importance of pulmonary function in spinal cord injury. We want to describe the limitations of the current methods of evaluating spinal cord injury, focusing on the neuromuscular evaluations and electrodiagnostics, I should say. We want to demonstrate how ultrasound can be a useful tool and be integrated into your clinical practice for allowing real world use. And then we want to evaluate potential avenues for the use of it in monitoring pulmonary function long-term in spinal cord injury. So we're going to first just do a very brief overview of just why it's important in spinal cord injury. So a lot of us are familiar with the anatomy of the human body and what goes into breathing. And we have a lot of different muscles and a lot of people think mostly about the diaphragm, which is what we're going to focus mostly on today, which comes from C3, C4, and C5. And that's going to play a big role in inspiration, but we also have our accessory muscles or abdominal muscles or intercostal muscles, even things that have cranial nerve involvement, all playing a role in respiration. And depending on the level of injury, it can significantly impact the ability of an individual's ability to breathe. And whether that's just the inhalation process, which is more diaphragm or just clearing excretions, which is a really big part of it and clearing secretions through abdominal muscle use is all really important. And we tend to think about folks with that injury in the C3, C4, and C5 region being mostly impacted and thinking about how that impacts their diaphragm function. And that's going to be a big part of where our focus will be today is folks with those types of level of injury being just around the levels that are going to impact the diaphragm. And one of the reasons we care so much about this is because we know that it really makes a big difference, that we know that if folks stay on a vent, which is what tends to be the case in those who have injuries that are impacting the diaphragm, they have a, like it says here, a 40 time increased mortality rate within the first year after their injury compared to those who are off the vent. So long-term mortality is also higher, although not quite as high, but still plays a really big role in their overall prognosis and care. We also know that just being on the vent limits what they're able to do functionally, thinking about transferring while being attached to a vent or trying to get out to the community with a vent. All of these things are additional factors that families and individuals who are just trying to get out, maybe who are using like a power chair, let alone trying to get out using a vent as well. So it's really important. And again, that caregiver demand has really increased because now you're not only worried about, okay, how's their bowel, how's their bladder, are they getting autonomic dysreflexia? Is their vent still connected? Are they actually being kept alive right now? Right? So you really have to be thoughtful and careful about what their vent is doing and how they're doing. And just, you know, the anxiety that comes around with it is all really important. We know that patients have expressed a high amount of fear in surrounding the variables that could go wrong and things that could compromise their safety. They already have so many things that are out of their control. To let alone lose control of the ability to breathe is something that just really can impact the individual and make a big difference. And a lot of times when folks are on a ventilator, after their initial injury, they end up going to like an LTAC, which is that long-term acute care hospital, or maybe they'll just go off to another facility where they're just maintained on a vent for a while, because unfortunately not all acute inpatient rehabilitations are able to accept individuals on a vent. So it takes a really long time for them to get weaned off the vent, if that's even possible. And again, Dr. Bhatia and Dr. Franz will discuss a little bit more about some of the considerations that will go into vent weaning. But we know that rehabilitation is so important early, right? We know that a lot of the neurological recovery after spinal cord injury happens in that first year, and what they're able to achieve in their rehabilitation during that time can impact it. So by delaying that ability to start their rehab because we need to focus on their pulmonary function can really impact their long-term recovery. So getting them to do regular, you know, their PT and OT and the speech therapies early can make a big difference. And when they're at an LTAC, that's going to play a role. And they can end up with a lot more complications when they're in a facility like that. So we want to try to find ways to help them get sooner, get evaluated. Hand it over to Dr. Bhatia. All right. I guess we'll move on to our next objective and talk about electrodiagnostic methods of evaluating diaphragmatic dysfunction. Thank you. And so when you have a patient with a spinal cord injury with respiratory dysfunction that you think is related to diaphragmatic dysfunction, you're kind of really asking, what is the source of their weakness, right? Is it critical illness myopathy, as Dr. Stone mentioned, oftentimes these people go to an LTAC. They've been sick for a while, right? So is this an intrinsic muscle issue? Is their actual phrenic nerve intact? Should it be damaged from their initial injury? Or is it weakness from their spinal cord injury, right? So are those alpha motor neurons at their C3, C4, C5 levels intact, right? Because those are the ones that are going to your diaphragm. And so one of the common ways we evaluate that is looking at the nerve conduction testing of the phrenic nerve, right? Is this nerve intact as we try to figure out the source of their weakness? And so a brief description of that, if you haven't thought about this in a while. For your nerve conduction testing, right, we typically stimulate at the neck, right behind the sternocleidomastoid, where it shows there on the figure over on the left, and then can record under the xiphoid process and have you reference under the costal margin at that mid-clavicular line. And the response that you get when you stimulate it is relatively small compared to your, you know, your abductor pulsus brevis and other hand muscles that you would typically do. And so a normal amplitude is typically between 0.3 to 0.5 millivolts. Next slide. So one of the advantages of doing a nerve conduction is that it gives you quantitative information about the health of that nerve, right? You can look at the latency, right, is how fast is this going? You can look at the amplitude to see if there is a reduction, is generally a demyelinating process or an exonal process. And so it gives you the quantitative information. Another advantage, and I think it's one of the main ones, right, is that it does not require voluntary activation, right? And this is particularly important in our population of spinal cord injury, where they might have lesions to the descending tracts of the upper motor neurons, so like your cortical spinal tract, right? And so then are they weak because they can't activate, right, or are they weak because the actual upper motor neurons have been damaged? And so when you do your nerve conduction testing, it's independent of the ability to voluntarily activate, and you can actually assess how intact that lower motor neuron is. However, this is one of the more challenging nerve conduction studies to do. It can be uncomfortable for the patient because we're stimulating at the neck. There can be other things that make it a little bit more challenging. So for example, if the patient has a trach collar, that can make it difficult to sort of get to that site, doable, but difficult. If they have a C collar, so if the spine is unstable with that collar, you can't remove it, then you know you can't stimulate. But if you have to maintain precautions with it removed, and that makes it, and you can't move the neck, it makes it a little bit difficult to get at that site. Sometimes we're asked to do these studies when the patient is still in acute care or in the ICU, which adds an extra layer of challenge. So you can have a lot of electrical noise, particularly in an ICU room where you can't disconnect things that would interfere with that really small diaphragm response. You could have things like central lines or external tubing from ECMOs that interfere. And then on a more broader scale, not just an SCI, but sometimes people have LVADs or these balloon pumps and other devices that make the phrenic nerve conduction contraindicated. And then one of the main issues that we've come in contact with and also makes this challenging is you're stimulating at the neck, and it's really, it can be difficult to selectively stimulate that phrenic, right? Because you've got your brachial plexus and your roots and your trunks coming out there. So when you stimulate the brachial plexus and get volume conduction from, say, activation of pectoralis, activation of your serratus anterior, and that can result in a high false positive rate. Next slide. In addition to the nerve conduction, one can also do a needle electromyography, a myographic study. Also gives you, helps you with etiology, right? And so when you look under that, look at the action potentials of the muscle with your needle, whether it's a neurogenic change or a myopathic change, you can differentiate that with your needle EMG. And to some extent, it also helps with that upper versus lower motor neuron. When you look at, you know, is it, do they have difficulty activating the diaphragm or is it more difficulty recruiting the units? As you can imagine, it can be quite challenging to do this study, where when you're typically inserting that needle, there are a lot of important organs there, and so you don't want to insert into the abdominal cavity or within the lung parenchyma. And so there's this additional layer of risks. In the picture on the left, you see them using ultrasound for guidance, which helps mitigate those risks, but I add another layer of technicality to the study. And it can, again, this one's a needle, and so sometimes some patients are uncomfortable with the needle examination. Next slide. And so just an introduction to ultrasound, as you can imagine, there are certain benefits of ultrasound over the previous two methods I just described, where noninvasive, it's a lot more tolerable, and it doesn't, it's not affected by your surrounding, you know, wires and tubing and electrical noise and interference, which makes it a better alternative in multiple locations, whether you're in an outpatient setting, in a patient rehab setting, or in an ICU setting. There are two main ways that we would typically approach an ultrasound for the diaphragm. I'm going to focus on one method here in this figure, which involves inserting that probe at the mid-anterior axillary line at the eight intercostal space with that probe oriented longitudinally. It's one way that we would typically look at that diaphragm. And so next slide. And so when we put that probe in that orientation, this is what we would see. I will direct you to the figure on the right, a big circular, and I don't have that at all. Thank you, Dr. Stone, for pointing, or is that mine? Oh, that's my arrow. We've got your rib here, so that's that rib, eighth rib. And so to the right of the rib is your eighth intercostal space. That arrow there is pointing to the individual's diaphragm, and so that bottom, the bottom border would be your, sort of the border of your peritoneum, and the top border would be your costal margin. And so basically as they breathe in and your diaphragm thickens there at that total lung capacity, we measure the thickness of that diaphragm at that max inspiration. And when we're doing this, we're looking for other things as well, right? So above the diaphragm, you'll have your intercostal muscles, and then above that, above your rib, your other muscles, in this case, I believe this is the serratus anterior. But when we look at that figure on the left, it's that same individual now exhaling, and you see that you can measure the difference here at end exhalation. And so one is looking at the thickness, and two is looking at that thickening ratio, like what is that change from exhalation to inspiration, right? And so we assess that ratio as thickness at that total lung capacity divided by the thickness at that functional reserve capacity. And looking at normative values that have been published in literature, it's typically above 1.2. Okay, great. Next slide. And so you might be thinking, well, how accurate is this compared to the needle EMG and the nerve conduction studies? And so there is something, there's work published in literature looking at the sensitivity and specificity of both methods. And if we compare the specificity of the nerve conduction at about 87.5 to the diaphragm ultrasound on this study by Andrea Boone in 2014, the diaphragm ultrasound had a specificity of 100% for evaluating diaphragmatic dysfunction. The sensitivities are actually comparable, but you see that the diaphragm is really better able at sort of removing these false positives that can occur. Next slide. And in all of the, sorry, in the previous slide, those were all out in outpatient settings. And if you recall, as you would imagine, in an ICU setting, it can be more challenging. And so this is some data from work that we had done that's unpublished looking at nerve conduction results versus ultrasound in the ICU for evaluation of diaphragmatic dysfunction. And this was in a cohort of 22 hemidiaphragms. The sensitivities in this study for the nerve conduction was 92%, which is similar to that outpatient setting, and 85 for the ultrasound, whereas the specificity was 100% for ultrasound and only 33% for nerve conduction study. Obviously, that's different from an outpatient setting, but I think it can be easily explained when we think about how difficult it can be to isolate the afferent nerve in the ICU setting. All right, here we go. One more slide and I'll hand it over. Correct me if I'm wrong, Dr. Attaway, but I think a lot of those conductions were performed by neurologists. Yes. Just thanks for confirming that detail. You are correct. I will say no more. All right. Dr. Shea, Dr. Stone? Yeah. And then this was just another really nice summary slide just showing the comparison of all the different ways that we can assess diaphragm function and its comparison to ultrasound because, Dr. Attaway spent a lot of time talking about the EMG and the nerve conduction components, but there are also other things we look at, fluoroscopy, doing like the sniff test or just a chest radiograph looking for an elevated hemidiaphragm, and you can just see here that the sensitivity and specificity are better for the most part in ultrasound compared to some of these other modalities. So this is just a really nice graph that put all that together. All right, I'll kick it off to the other two now. All right, we're gonna talk a little bit more about like putting this to practice at the inpatient rehab setting. Can we advance? So I guess I'll reiterate a few points. What was happening at our institution, and I know it varies across the country, patients go to LTAC, they come to us with a lot of complications, maybe more than things that we felt like we could have prevented, pressure sores, contractures, but they need to go to the LTAC in order to be weaned off the ventilator in order to qualify for inpatient rehab in some settings, or at least that's strongly encouraged, you know, to take care of that before beginning the inpatient rehab program. We felt like that perhaps there could be advantages to doing both together in our setting. And, you know, it involves a lot of people to come up with a protocol for doing this. I mean, just something is, I think a lot of people could relate to is getting buy-in from like a respiratory therapist to follow a particular protocol if you're gonna spend a time off event in a structured way, nursing staff that's involved with both like that protocol, but also like, you know, coordinating with cardiopulmonary physical therapists to engage some of the accessory respiratory muscles as well as look for signs of diaphragm engagement. It goes on and on. And so by leveraging, I think like, you know, our team approach here, which I think it would be not too different what's possible at other institutions. I think that that along with incorporating a lot of data collection research and then just having institutional buy-in was like kind of the essential ingredients for us to make progress with this program. Advance. So what we created, I mean, I took a lot of slides out because I figured it'd be better to get to the point, having some time for discussion, but really one of the backbones of what we're doing is like really, in addition to taking on these patients is having a plan for upfront assessments. So things that we can objectively measure, you know, chest wall excursions, which are often picked up by some of the cardiopulmonary physical therapists I work with. We have increased our FTE of pulmonary medicine that's at our hospital so that we basically have 100% FTE now so that we have support, but taking vital capacity measurements, negative inspiratory force, some of the standard measurements that are done and I think in a lot of places and traditionally done as well as diaphragmatic ultrasound, which Dr. Attaway was touching on. Dr. Bhatia is gonna show how useful that tool is and it's becoming increasingly available across the country. Big shout out to Dr. Boone, Andrea Boone at Mayo Clinic. Not only, she wasn't the only person developing a diaphragm ultrasound, but I remember hearing about her first experiences with it and what inspired her to do it and it was actually a patient with a high tetra from cervical spinal cord injury. That was one of her first cases that really developed that interest for her and it has really brought impacts beyond the SCI field, but you'll see a little bit more about that. Interventions, and I think that we chatted a little bit about the interventions, particularly speech therapy as well as at our institution using things like inspiratory and expiratory muscle training devices and why don't we advance some of the basic things in our treatment algorithm. So in Dr. Bhatia's paper, we actually published the algorithm in more detail if you wanted to look at it, but sort of establishing a go and no-go criteria. Basically, the common thread of it is if the diaphragm is engaging robustly, you're probably gonna be able to green light go. If it's not engaging really at all, which we'll hit on, don't advance yet, but you're probably not gonna go and if you're sort of in between, sometimes like a hemidiaphragm pattern, what have you, or just really long-term ventilation status that leads to ventilator-related diaphragm dysfunction on top of the spinal cord injury can lead to these yellow light situations where you can make progress, but we have to slow it down. And you can see some of our usual parameters, vital cap, NIF values. I mean, it's not a trivial thing to also just like medical comorbidities, like pneumonia, secretions that are gonna get in the way that you can tolerate sitting upright that you're not so orthostatic. You know, all things that you don't often think about if you're like a, I sometimes joke I'm a bit of a diaphragm dentist at times because I'm just thinking about the muscle, but there's like a person attached to the muscle. Advance. Which my colleagues in spinal cord injury medicine remind me of very often when I tell them what I think about my ultrasounds. And then, you know, if there's like any instability, poor pulmonary parameters and weak cough can all get in the way. And certainly, why don't we advance? I think that's gonna lead us to Dr. Bhatia's work here. So why don't you take over? Perfect. So this is just another kind of schematic of the setup of the diaphragm ultrasound that Dr. Attawee went over. Next slide, please. So what I'm gonna talk about is I am going to share some of the results of our retrospective review, looking at a cohort of patients with traumatic cervical spinal cord injury coming into inpatient rehab, needing mechanical ventilation. And this was recently published data. So next slide, please. So we hypothesized that intact contractility of the diaphragm on a diaphragm ultrasound evaluation would be a positive predictor for being able to wean from the ventilator in these patients, even if other kind of traditional methods of evaluation were not pointing in that direction early on. So next slide. So our study looked at 21 patients here who were admitted to the inpatient rehab unit, all of them requiring the ventilator at the time of admission. All of them had traumatic cervical spinal cord injury. Neurologic level of injuries ranged from C1 to C5. Asia impairment scale A, Bs and Cs were included in our study. And the age range for these patients was from 17 all the way to 78 years old. And you can see here, we basically grouped them into a group that was able to wean from the ventilator at discharge, and then the group that was not able to wean. So next slide. So of the 21 patients that we included in our study, 11 of them were able to successfully wean from the ventilator, which we defined as either full daytime off the ventilator, but with nighttime vent use or 24 hours completely off the ventilator. So those were our successful weaning group. And then 10 of these patients were not able to wean from the ventilator. Next slide. So when we look at the group who successfully weaned from the ventilator, all 11 of those patients had a normal thickening ratio. So if you remember from earlier, the thickening ratio, a normal thickening ratio is greater than or equal to 1.2, which is basically that measure of contractility or how much the diaphragm muscle is thickening as it's being activated. So all of those patients that weaned from the ventilator had normal thickening ratios. When we look at the group that was not able to wean from the ventilator, all of them except one patient had thickening ratios that were below that cutoff of 1.2. So as you can see from these numbers, very high sensitivity and specificity within our specific patient population when we used this cutoff. All right, next slide. So similarly, when we calculated the mean thickening ratio, again, that group who successfully weaned off the ventilator, the mean thickening ratio was 1.6. So again, very much into that the normal contractility category. For the patients that did not wean, mean thickening ratio was 1.1, again, below that cutoff. Next slide. So really what we took from this data, this study really demonstrates that a normal thickening ratio is a really strong predictor of successful bent-free breathing. And that intact contractility when we see it on the ultrasound can really indicate weaning potential for patients who we would typically maybe not expect to wean from a ventilator based on either their level of injury or other traditional kind of metrics that we look at. So for example, in our cohort, we had two patients who were classified as C2 Asia Impairment Scale A, C2 Asia A, that actually had intact contractility of their diaphragms and they were able to wean off the ventilator, where if you look at the data, patients of a neurologic level of injury, C2 or complete injuries are typically not expected to be able to breathe off of the ventilator. All right, and next slide. So these findings have really allowed us to develop a treatment pathway that really guides our approach to ventilator weaning for our patients with spinal cord injury on the ventilator. And we really start with this evaluation of diaphragm atrophy as well as contractility during the kind of initial comprehensive evaluation for patients with spinal cord injury on the ventilator. You know, the first thing that we look at is really that contractility or that thickening ratio. If contractility is intact, we typically consider these patients good candidates for eventual weaning. If the contractility is present but impaired, you know, this is kind of our like, Dr. Franz was talking about like red light, green light, yellow light. So present but impaired contractility, those patients are the ones that probably require further optimization, like using the cardiopulmonary rehab strategies, RMST. But, you know, we want to do that first before we kind of move forward or consider weaning from the ventilator. For those patients that really have absent contractility, this is when presence or absence of diaphragm atrophy can really make a big clinical difference. If there is no diaphragm atrophy, this is kind of more indicative of that pure upper motor neuron injury. And those patients are typically or can be considered potential candidates for a diaphragm pacing, which we'll talk about a little bit more later. If there is significant atrophy of the diaphragm, that's when you have concern that maybe there's a lower motor neuron injury that's causing denervation of the diaphragm. And those patients are typically not candidates for a diaphragm pacing. So this is really the kind of treatment pathway that we use as we are evaluating patients coming in on the ventilator. And next slide. So just some kind of key ideas. We have found that diaphragm ultrasound is a non-invasive, accurate, and real-time method of evaluation of diaphragm dysfunction. The benefits are it can track and monitor function over time for some of these patients. We did the initial ultrasound and then at kind of key time points in their rehab course, we did a follow-up ultrasound to see if there were any changes. The diaphragm ultrasound can help distinguish between upper versus lower motor neuron diaphragm dysfunction and potential diaphragm denervation. And then really the evaluation provides really critical information that helps determine appropriate clinical pathways for respiratory management, really with the goal of more efficiently and effectively progressing patients to ventilator-free breathing. And next slide. All right, so we're back to the program here. And so we wanna tell you a little bit of, like, so this program we launched, we had been planning for more than a year, but we launched in 2021. We looked at numbers from just before we launched and then just after. Granted, it was a little bit of awkward timing with COVID, but why don't we advance? I'll show you, I wanna share, like, the, I think, you know, being able to determine who's ready or who's a good candidate is really key. And there's sometimes patients, like we just, I just saw someone on the weekend whose regular numbers look bad. And you do the ultrasound or you do your assessments and you see a glimmer of hope. And this is, like, what we're talking about. It's not all the spinal cord. I mean, ventilator-induced dysfunction on top of the spinal cord injury can really make someone who looks like they couldn't possibly wean, you know, get sort of overlooked when you actually see some really encouraging signs that if you give them some interventions, and for us, it's usually ventilator-free breathing with increasing time off event, that if you give them a chance, that sometimes they can make some real strides. So once we, the ideal situation is we get the ultrasound now first before we decide on the cardiopulmonary intervention, the ventilator-free breathing. And then this will automatically start triggering our cardiopulmonary physical therapist, speech therapist, to start with respiratory muscle training, advance. And so here's the key thing. First of all, like, this is just sort of summarizing some data before we started and after we started in the two columns, the 2018 data, which is before we started our formal program, and the 2021 data. The first thing that jumps out to you is like, we actually look at the number of patients we admit with Vents and the number of people who wean. It doesn't change. So we're not actually getting more patients off of Vents necessarily than we would have doing things the old way. What was happening actually is that when we do the assessments, we catch that someone has the potential to come off of the Vent sooner. When we use a more structured approach, which, you know, we didn't give it full details on, but happy to, Dr. Alex Kim is the champion of this in our hospital in terms of actually how we do ventilator-free breathing based on like the data and the literature that supports it. But the key thing with the assessments is that we get them off more efficiently because it takes less time to identify someone who has the potential to improve with ventilator-free breathing and with cardiopulmonary interventions. And not only is it like a shorter period of time till we get them liberated from the Vent, but it's also like a shorter period of time during their admission till we start to initiate the interventions. And so the structure of what we're doing in the assessments early on, even for patients that we don't think will come off the Vent, I think allows us to make early identification of the appropriate candidates for ventilator weaning. Do you want to advance? And at the backbone of it all, it seems to me has been, and it's a little self-serving, with us being the neuromuscular people doing it, but is the ultrasound has been such a useful intervention for us. So, I guess if I can highlight anything is like you gotta have a big team. I mean, we're not giving you the full perspective on it, but we can in the course of this hour teach everything. But like what's novel about what we're doing is using some of the advanced assessments, incorporating like the more data, adding data to the literature about how to do this better, and then really embracing the availability of point-of-care ultrasound now virtually at all rehab facilities, so that if there's someone trying to do these assessments, you have what you need in order to start addressing some of these issues. And we can advance. And getting patients into inpatient rehab and skipping the LTAC or getting them here sooner, it seems to be paying dividends to us. And there's a value to that in terms of just getting started on the acute rehab sooner and not having to wait for the ventilator weaning to be addressed at a third site and just get them right to from A to B instead of A to C to B. Advance. All right, Dr. Stone. Yeah, I'm gonna rapidly go through my stuff because I'd rather give us some more time for conversation and then if you all can go more in depth on certain things. This is just, we're gonna look a little bit about potential use for ultrasound in monitoring long-term. As Dr. Bhatti mentioned, sometimes we can do these interval evaluations. And a lot of times in the outpatient setting, we're monitoring pulmonary function using like peak cough flow or proper spirometry. But that can be really challenging. A lot of these folks, even if we get them off the vet, often still have their trachs. So some of the normative data is not appropriate in assessing how they're doing and you're not actually getting accurate data. So I thought that ultrasound might be a really great modality and way to look at this, especially because we know that although PFTs include a lot of different values, we know that vital capacity has been shown to correlate with many of the other outcome measures. So we can find things that correlate well with the vital capacity and peak cough flow, which are two of our important components of long-term monitoring. It would make a big difference. And especially we know that vital capacity is really important because it plays a big role of, a lot of it comes from the diaphragm, which we talk about as a really important muscle when it comes to inspiratory function and breathing. And we also know that that vital capacity correlates with neurologic level of injury, right? So we can expect that there are going to be these decreases as we get higher and higher. We need to figure out a way to monitor it. So my goal was trying to see, is do any of our ultrasound measurements correlate with some of the things that we typically think about in long-term management in folks with chronic spinal cord injury, vital capacity, peak cough flow, and neurologic level of injury? Come on. There we go. And I hypothesized these things, but again, we're gonna go quickly because I want you all to know, we had similar inclusion, ABs and Cs, cervical injuries. Most of the folks had pretty normal of their outcomes. And this was just what was interesting. And again, this was a small pilot study, so pretty small. And we found that thickening ratio tended to correlate pretty well with vital capacity, which we would expect considering thickening ratio is looking at that diaphragm function. And we know that vital capacity, a big part of that comes from the diaphragm. So that was really exciting and interesting. Then we also had excursion, which we haven't really talked about a lot in this session. This is another way that you can look at the diaphragm function. You look at it more from an interior view, looking at how the diaphragm is moving. This also showed a moderate correlation with vital capacity. And then one of our strongest correlations was, you can see here, excursion with peak cough flow. And again, peak cough flow is so important in terms of the functionality of our patients, being able to clear their secretions. And we know the data shows that peak cough flow can play a role in predicting a patient's ability to decannulate and get off the vent. So being able to monitor these in an outpatient setting can be really helpful, but it's really hard to do spirometry because of trachs. And sometimes to do full spirometry can take a really long time. As we know, folks with spinal cord injury have to reposition and move around a lot to prevent pressure injuries. So if we can use something like ultrasound, it could be really nice to have another way to monitor it. By no means is this going to be able to replace it, but perhaps again, as Dr. Franz mentioned, most hospitals now have ultrasounds. Most clinics also have ultrasounds now. They might not have the capacity or have the equipment to do peak cough flows or to do final capacity. I can say like anecdotally in my clinic, since all of the trade things have been happening, it's been harder and harder for us to do spirometry in our clinic with our respiratory therapists, but an ultrasound, all we need is jelly in the machine and we can do that regularly. So it would be really nice to have this. So if I can monitor their function using the ultrasound, and if I see a major change that then triggers the need to get spirometry, that could be way better than the typical guidelines which say we should be monitoring them every year or so with spirometry. Again, this was a pilot study, so the data is a small end and there's more work to do on it, but I think that this is a potential area of further investigation, especially also areas of looking to see if there are some functional, if there are some ultrasound measurements that correlate more with level of injury. Our research didn't necessarily show that, but since we know that vital capacity does correlate, we think that maybe a larger end might reveal that or because we know that there's a difference between motor and neurological level, but again, I don't want to go on for days. I want to give us 10 minutes for questions. So I'm going to wrap up quickly there. Sorry for my rapid fire, but yeah, please, if people have questions either in the chat or if they want to unmute and ask questions, we really want to engage with folks because we're all really excited about this technology and its potential benefits. I also have some questions. I can just ask the group if if there's none from there's a there's something in the chat What would be patient position during ultrasound exam what's the billing code that could be used I Could answer the billing code question and then not let other people comment on positioning so you can do There's a few options, but like if you're doing an ultrasound you can do Basically a lung Ultrasound or chest ultrasound and I could get the billing code to you I Have it. We're not using it due to some limitations because there are hospital doesn't want me using it but we I did do some research and have a So if I'll put my email in the chat I can send some information to you and Actually, that is definitely get generates more abuse or or or billing if you do it as a diagnostic scan and it is possible I sorry, I don't have it right on the top of my head But I don't know if anyone else is actually billing for these as a diagnostic scan I and so since I'm not doing it as a diagnostic scan. I'm currently doing it based on my time, which is Yeah What I'm allowed to do Yeah, I would say right now I also Just like bill it for my time But I'll like, you know put the documentation of like what I did and like what I was seeing such Same here And with regards to positioning it typically have them supine With their head up, you know, 30 45 degrees And it can be up even more than that if needed if they're having more difficulty breathing But that allows me to look at both sides of that made into reacts very long I'm curious if there's any research in the field is gearing this towards progressive neuromuscular disorders like ALS wherein you need frequent pulmonary function tests as well, like if there are Correlated ratios that are similar to what we're seeing here with spinal cord injury. Are there any comments from the panel regarding that? I can I could come in if anyone so I do so when I learned this I was thinking I was going to use it in my ALS practice. I do ALS care as well as part of like an interdisciplinary clinic format But as it turned out I've used it mostly in ALS when there's like a ball bar patient that doesn't do well with regular spirometry Just as a sanity check because they'll often have really bad office spiral numbers And then we're thinking they're doing way better than how they look, you know They've got a good blood gas or we did, you know Check their bicarbonate on a blood draw and it doesn't look like they're really in respiratory failure And so it's very reassuring then to see good technique ratios on both sides and good measurements, but I will say that just using it as like You know to put people into like a category of normal versus abnormal Is pretty effective, but when you start getting into these sort of gradiation of like as their disease is progressing My experience is because there are some sampling issues with like repeated measures that it's hard to mitigate without being really really Careful about exactly how you're doing the study the positioning the exact location of the ultrasound I would say that You know you get that variation Pulmonary like this office spirometry or pulmonary function testing is probably good at showing that that more of a graduated change over time Whereas if it's like a phrenic neuropathy or diaphragm paralysis from spinal cord injury It's really good at putting them into a category or bin for you to then make some decisions like and like I said we I think It came up a few times like red light yellow light green light, but it's sort of like that like we're pretty good at putting them into one of those three categories and then the rest of it is Maybe I think harder to get like Really, you know three month intervals between ALS visits. It's hard to really be confident that you're you're accurately measuring change over time and Fundamentally, those patients are also expected to get kind of gradually worse so So in the case of a spinal cord patient, you could actually see a diaphragm sort of kicking back in so it's pretty nice to see that as well, so I I found it more useful there, but Uh, certainly you can find scenarios where it's helpful That makes a lot of sense. Um, and just the sort of binary nature that you're describing makes me wonder if that is secondary to like a dearth of data that shows The strength of these correlations so we can't really map them out Or is this more of a matter of Interrater reliability or like user error with ultrasound versus pfts. Do you think Uh Yeah, I think it's just uh I mean, I think even when you do really careful You know same person same, you know, like measurements over time you have to deal with some of this variation. It's really hard to mitigate um With technique, so I think it's just the like limitations of the test. It's it's it's got its purpose, but I tend to Think that um, there's probably better instruments for measuring small differences over time and uh If anyone else wants to offer opinion Never mind having someone else do the scanning which uh, you know, we've found ourselves doing it at times like interchanging scans And it it's doable but it's um, it's good to space out the scans over, you know longer intervals In other words you have big big changes over longer periods of time and therefore you capture those without too much difficulty But it's yeah, I wouldn't say binary, but there's it's probably not you know, it's good for bigger changes Yeah Yeah, and that's part of in what I want to do if I had time to do like a long-term study or maybe I had Someone you could partner with is is doing measurements over time like in a patient to see how it goes Like dr. Franz mentioned maybe doing more something like annual um, especially like again in the sci population where if they're making changes, it's not because usually because of like a neurological progression It's more just because All of us over time our vital capacities are going to get worse Um, and we just know that like in sci they just have less of a reserve So if you maybe look at it at those larger changes over time where we know that annually they are getting worse Because all of us do that's where you might capture something You know, I it just occurred to me. Uh, we took out the thing on like using the ultrasound to titrate a diaphragm pacer But that's a really good example Where we turn the settings up gradually and you can get like five or six different data points with different thickening ratios Uh granted you have the advantage of doing it all in one setting One position and the ultrasound basically fixed in the same place the whole time so it is possible uh Zachary to to get a little bit more detail, but um But I think there is like always a session to session issue in terms of just how they're positioned I mean even being supine versus upright the question came up Can impact some of the parameters a little bit and that's been documented by andrea boone And probably other people but I know i'm aware of her study A few minutes left if anyone else has a question I have a question. Dr. Bathia has also used this in stroke patients A little bit uh, which is And there's some a little bit of data out there on that Do you want to comment that might be interesting to the group? so we are starting to um Starting to look at the the same data for patients with uh, locked in syndrome Who come to our rehab units? Um, they don't um, you know, they're we don't take patients with uh on the ventilator who have Brain injury or stroke so they're coming in typically with a trach but not on a ventilator um, but some of the um, you know that they have similar respiratory dysfunction with that neuromuscular respiratory dysfunction as a result of the um, you know that that quadra quadriparesis Um, so we are collecting that data. Um, it's a very small patient population so it's going to take more time than with our spinal cord injury data, but Stay tuned I'm supposed to help with that. We never had anymore. I'm glad it's growing Yeah, yeah, it's um, I think I think the thing with some of the um upper motor neuron injuries too Um, is that if it's cortical versus if it's brain stem you know pons even medulla it makes a difference because there is um, uh some of the issues with with quiet breathing You don't see a big change in the thickness using our Rb mode technique, but dr. Stone we didn't talk a lot about the m mode that he does. Uh as well You do have um, it may be a better technique for those patients. Um, uh, because you can You know see uh some excursion with quiet breathing. That's um that um With the thickening ratios in some patients. They don't even change with quiet breathing. It's you have to take a deep volitional effort. So Uh matching the uh the way that you do the scan to the clinical scenario is important But it adds time Valuable time. Yeah, and I would say having now that I do Well, I mean I still do the b mode more than I do the m mode But like I mean I do like the excursion sometimes it's it's a technically more challenging study as well Um to get the to get the m mode, um compared to just scanning and looking at that thickening ratio Okay, um michael do you have anything to to add we're already losing our audience No, uh nothing on our end. Um, feel free to if you guys have any closing sentiments or you know, whenever whenever you guys are good You know, we're we're good to go Yeah, uh, thank you all for your attendance as mentioned it's recorded if you have questions Feel free to reach out to any of us. We'd be happy to and join our communities and to learn more

ultrasound

diaphragmatic function

spinal cord injuries

ventilator management

real-time monitoring

rehabilitation

weaning potential

respiratory function

collaborative effort