Thank you all for coming, I know it's late in the day and everybody would rather be on the beach I'm sure, but we'll try to make this as painless as possible. So we're going to be going through the evaluation of neuromuscular weakness and the management of neuromuscular weakness in the ICU today. I'm Bethany Lussier, I come from Dallas, Texas, where I practice neurocritical care, pulmonary care, and neuromuscular pulmonology, and I'm the director of the Parkland Medical ICU. I don't have any real disclosures that are relevant to this particular talk, although I do have a few, and the objectives for my particular portion are going to be going through the initial assessment, the bedside assessment that you're going to complete for patients with neuromuscular weakness, kind of determining the acuity of the weakness and using that to make some clinical decisions on how to intervene on airway, ventilation, and just generating a differential, and that will lead into the rest of the talks that follow. When you're looking at ICU admissions overall, neuromuscular weakness doesn't really account for a ton of them, it's less than .5% of all ICU admissions, but there's still a huge burden to the actual workload in the ICU. If you look at average lengths of stay, it's at least double what an average patient who does not have neuromuscular weakness is going to spend in the ICU, and the associated expenditure and resources that we put into them. They're going to fall into, it's easiest to divide them into three main groups at least. Patients who have severe new onset neuromuscular weakness, patients with existing chronic neuromuscular weakness who develop some sort of new acute complication, or patients who have neuromuscular weakness that arises while they're actually in the ICU. That's a whole large topic in and of itself, so we're not going to spend a ton of time on patients who develop it in the ICU, but it is going to be an important cohort of that population. Patients who tend to have severe new onset weakness that you will encounter in the ICU, they're going to fall generally under certain categories. The ones that you'll see most prevalently, the Guillain-Barre's, or the acute severe peripheral neuropathies, acute myopathies or myositis. You'll see a handful of acute flaccid paralysis that comes with either West Nile or Enterovirus, although usually they end up in the ICU with Enterovirus because of encephalitis, not necessarily because of the weakness. Myasthenic crisis, other neuromuscular junction disorders, and then new manifestations of chronic diseases. Now ALS you may not see as a, it's not an acute ICU issue. The problem is that there's so many delays in diagnosis, and we diagnose ALS as everything but ALS before they actually get diagnosed as ALS, that you may actually encounter them first in the ICU. PLS, progressive bulbar palsy, that type of thing. So they don't necessarily present there, but they land in the ICU and then get their diagnosis. So they do make up a decent amount of our cohort. Critical illness neuropathy is actually the most common cause of new onset weakness in the ICU, and you do encounter that pretty frequently. It's probably underdiagnosed. Conservative management, it's going to go undiagnosed. The bedside assessment initially when you're walking up to a patient is going to be who needs the ICU and who doesn't. And the bar is different for everybody based on what kind of resources you have and what kind of monitoring you have available. But patients with severe respiratory weakness end up in the ICU almost across the board. That's a pretty obvious one because the step up is going to be something invasive or non-invasive and truly time intensive. Bulbar weakness and a high risk for aspiration and a chronicity does matter. Cardiomyopathy or decompensated heart failure is something we will see commonly, especially when you're talking about patients with chronic muscular dystrophies or congenital myopathies who have a comorbid cardiomyopathy. Arrhythmias are common and not just in the patients who have underlying cardiomyopathy related to chronic neuromuscular weakness, but you can also see it in some of the ones that go undiagnosed, the acid malatase deficiencies, the carnitine deficiencies, that type of things. Dysautonomia we will see with a lot of our patients who have neuromuscular weakness. They're comorbid problems. You may see a lot of this with the Guillain-Barré AIDP. And then acute rhabdo and renal failure is something that you will see also associated with neuromuscular weakness. And you need to keep those in mind because it will guide you down your differential trying to assess what's going to be reversible and what's not. Respiratory failure is probably the most common reason they get admitted. You don't see a lot of patients admitted just primarily with neuromuscular weakness as a problem and oh, they happen to be admitted for an arrhythmia. It's usually the respiratory failure that brings them in, at least to the ICU component of it that requires the attention immediately. The manner and rate of decompensation is pretty variable, and it depends on the spectrum of disease and the trajectory of the patient. But you will see, like I said, the autonomic dysregulation that they have. Your initial assessment is going to be, because it's mostly respiratory, is are they autonomically stable? Are they able to protect their airway? And is there effective ventilation? And if you can assess those three things immediately, the rest of it can pretty much follow. So as long as you're focusing on those three things, you can assess, stabilize, and then reassess afterwards. Things that you want to pay attention to when you're looking at your patient, right out of the gate, you can gain so much from the physical exam. It can tell you trajectory. It can tell you chronicity. It can tell you where they're at. It can tell you what you've got to do in the next five minutes. And there are certain things that you're going to pick up on, right? There's things like, I'm smiling, but it's horizontal. I can't pull it all the way up. I can't pucker my lips, right? I don't have a strong suck. And those things are going to tell you there's something with bulbar weakness. They have nasal speech. Or they're slurring a little bit, and it's because they can't elevate their palate, right? Simple things. They can only get one to two words out at a time, and you can barely hear them across the room. That's obvious, right? That's pretty obvious. But if they're not short of breath when they're doing it, that may be a chronic problem they've adapted to. So it's just little things that you're going to pick up on the exam. Having them just something simple. Pick up your hands. Go like this. See if they can make a muscle. See if they can bring them together. See if they're coordinated. See if it stutters. Have them go like this. Do they get myotonia? Does it catch? Right? These are signs and symptoms that will lead you down the differential diagnosis, and it's nice to have that exam out of the gates, because if they're decompensating rapidly, you may not be able to get that exam two, three hours from now, or even two days from now. So having that initial assessment really helps. If they're using accessory muscles, and this is an important note, you need to be able to assess for accessory muscle use. Everybody knows this. It's on all your boards. But when you have neuromuscular weakness, and especially chronic neuromuscular weakness, you may not have accessory muscles to use. And so you really need to look at the patient and say, are you using accessory muscles? Do you have any that you could actually use in a crisis? And sometimes you need to provoke it, right? Can you lift your head up off the bed in the first place? Do you have actually a way to lift your shoulders? Are you going to be able to recruit those muscles in an emergency? So taking a look at the patient and actually putting your fingers on the patient. Feel them breathe. Feel whether the chest wall goes in and out. It's actually more effective than listening to your patient. Put your fingers on the intercostals and feel them. The other thing you can actually do is provoke it, right? You can lay them down flat. What happens when you do that? I don't know if this video works or not, but it may not work. But there's a nice video of abdominal paradox, so you can YouTube it. But putting a patient in a position where their diaphragm actually has to do the work and seeing if the belly sucks in or if it goes out like you normally would with a diaphragm excursion, it's telling, right? Tachypnea, important. When somebody with neurovascular weakness is starting to fail, and Dr. Sonati will go into this, you're going to increase your respiratory rate, and you're just not able to increase your tidal volume. And the patient can put themselves at risk. If the patient's been heading there for a long time, they may have adapted. And it may look very comfortable. And they may not even be breathing that fast. So it's a good idea to go in and actually touch your patient, listen to them, feel them, and incorporate all of the exam. Oh, I'm sorry. I can't move past this slide, can I? Sorry, guys. Oh, now it's showing a video. Okay, so that's abdominal paradox. If you've never seen it before, it's a pretty good one. There we go. So everybody remembers this from way back in med school when we were studying the exams. It's a nice diagram, and it's a decent rule of thumb. But that's what it is. It's a rule of thumb. When you're assessing neuromuscular weakness, these guidelines are helpful in an acute, rapidly decompensating patient. If your vital capacity is less than 20 mLs per kg ideal, if your MEP, which is the expiratory, how much pressure you can generate pushing out, saying, I can't clear my airway because I can't force anything out, or if your MEP is greater than minus 30, they can't suck in, that diaphragm is not going to pull in anymore, that patient's in trouble. However, we have all seen patients who have SMA who have been living with a vital capacity that's 12% of predicted for the last 20 years. So trajectory matters. These patients are patients who come in with Guillain-Barre or myasthenia gravis, who are rapidly devolving. So these numbers should heighten awareness that the patient has limited reserve and limited capacity, but you have to apply the trajectory of the patient on top of them. The other things that are helpful to ask your patient, it doesn't necessarily require the numbers. You may not have a respiratory therapist who can get these numbers, or they may have bulbar weakness that interferes with the measurement. Listen to the patient's voice. Is it high-pitched? Can you barely hear it? Can they lift their head up off the pillow? Can they count to 30? How far can they get? How awful do they look when they're doing it? If they can do it out loud in the first place. Palpate the accessory muscles. See if they can do it. Cough for me. Show me your best cough. It's a super effective exam, and it can be done within 10 seconds. When you're attempting, you've got to stabilize your patient. So you assess your patient and say, are they going to tolerate this or are they not? Do they need an airway now? And again, you're going to use those as a guideline. You're not married to that 20, 30, 40 rule. You're not married to it. But you can use it as a guideline saying, this patient is at risk. They're getting worse fast. I'm going to intubate my patient, or I'm going to put them on non-invasive ventilation, because they are clearly struggling to breathe. You're going to consider whether or not it's appropriate to intubate your patients. The best evidence is early intubation for patients who are going to need two to four weeks of continuous ventilation. Those are patients with AIDP, Guillain-Barré, somebody who has rapidly escalating requirements, who's going to have two to four to six weeks of recovery. So those patients are probably going to need to be intubated. And then you're going to figure out how to stabilize them after the intubation. And then you're going to work on reversing the underlying situation. The other ones you kind of have to consider trajectory. If there's bulbar weakness, you're going to decide whether or not it's appropriate to try non-invasive ventilation. If it's bulbar weakness associated with something like a neuromuscular junction disorder, that may be rapidly reversible. It may not be. And so you've just got to take the trajectory, the acuity, and what the next two years are going to look like. In ALS, for instance, you may really want to consider the trajectory, whether they have bulbar weakness, if they're heading towards intubation, if you think you're going to be able to liberate them afterwards, and of course what the goals of care are. A word of caution, when you're intubating these patients, everybody knows this. I don't even know if most places carry sucks anymore. Don't use sucks. It gets really ugly really fast. Don't use sucks. And if you can avoid neuromuscular blockade, all the better. Especially if you're intubating them for what you think is going to be a short term, because it really, one, they can be either hypersensitive or not sensitive at all, especially with neuromuscular disorders. You have no idea what dose is going to work for them, and you have no idea how long it's going to linger. So it can cause really prolonged neuromuscular weakness. They suggest kind of sedative hypnotics or sedative narcotics alone, if possible. And then if you can do a fiber optic control, it's actually better. Cardiac complications, this is real short, real brief, but a lot of these conditions will be associated with either cardiomyopathy or an autonomic dysfunction of some sort, or dysrhythmias. And some of these patients, especially muscular dystrophy patients, there's associated transplant population, and so there can be complications related to that. The things that they recommend, that are recommended in the literature, is short-acting medications. These patients tend to be hypersensitive, especially patients who are already labile. They respond very quickly and very dramatically to these medications. So the shorter-acting, the better. There are obviously some neuromuscular components that have some of these protein deficiencies that there are certain medications you should avoid. But typically, hydralazine, nicardepine, something, wrap it on, wrap it off, Esmolol if you need it, Dilt. And then if they have profound bradycardia, there's some suggestions there. And you can precipitate these with simple actions, suctioning, intubation. And so having them on standby is important. Just keep them in small doses. Once you assess your patient, you stabilize your patient, you decide airway or non-invasive ventilation, but you've secreted their ventilation in some way, take a moment and reassess. You're just trying to figure out what the next step is going to be. You need to anticipate it. Some of these conditions are going to be rapidly reversible if you meet the window. You've got to meet the window, though. Early intervention is always going to be better. If it's a medication that needs to be removed or an electrolyte that needs to be replaced, something simple like that, you can do it. You can do it quickly. But if you don't do it quickly, it's going to take a long time to recover. Severe hypokalemia can take four days for you to recover your muscle strength. So intervention is important. So you do want to reassess. But you're looking for the classic features. Is it fatigable, not fatigable? Do I have dysautonomia that comes with it? Is there cardiac problems? Is there muscle atrophy that shows this is a problem that's been going on for a long time so I have time to figure this out? Family history is nice to know. Undiagnosed things, the most common is going to be some sort of spinal cord disease. And so being able to differentiate upper and motor neuron issues is actually really important because you will end up missing some sort of spinal cord pathology. And they're usually, in acute situations, there's a reversible component. And so I urge you to reassess. Reassess after you've stabilized the situation. Reassess again. Because you don't want to miss the infarct. You don't want to miss the tumor, the bleed that's compressing on somebody's spinal cord. And then looking through, there's actually, I'm not going to go through this in any detail, but there's a nice algorithm. Widgix and his colleagues have written a lot on this, actually. And there's many papers on it. But if you go to anything by Dr. Widgix, he has a great algorithm to work through neuromuscular weakness in the ICU. And it doesn't portray particularly clearly. It's very easy to find. He's got a nice mnemonic for differentials that breaks it down, whether you're looking through medications. And there's a ton of them. Corticosteroids, neuromuscular blockade, the whole thing. Electrolyte disorders. Just breaking it down step by step. And then on the left there, you'll see there's an algorithm that works through the initial assessment, when to get an MRI if that's negative, when to go to the next steps. And some of these patients do end up requiring a more invasive workup to try to figure out what the etiology of the neuromuscular weakness is. And it's a good idea to go through that algorithm at least a couple of times. The real reason, and this is brief, but as the pulmonary group, I often see these biopsy results. And I'm expected to be like, well, okay, now you have a biopsy result or you have an EMG nerve conduction study. And I don't know how to translate this or make it usable. But at a certain point, you need to know when you need to get one. And you need to know what they're trying to tell you when you have it. And what it comes down to is understanding, is it a neuropathic problem or a myopathic problem? And which of these problems is potentially reversible? Because the ones that are reversible, I can fix. The ones that are not reversible, the question is, how fast are they going to get worse? Or can I stabilize them? Because it's going to determine what I do over the next two weeks for my patient who may be on non-invasive or invasive ventilation. So this was just a brief kind of, when you go through, you want to determine whether there's a neuropathic or axonal injury. And that may actually require you to get nerve conduction study or EMG to determine that. If you have a myopathic problem, it may be something like a myopathy or myositis, and you may need a muscle biopsy to do that. And then if you have the more common things you'll see in the ICU, criticalness, neuromyopathy, or myopathy, and those tend to end up getting a muscle biopsy or nerve biopsy if you're going to do it. And you will be forced to do that if you think there's a reversible condition you're missing. But those tend to be more supportive care. But they do make a difference in your differential. When they're handing you this report, it's kind of confusing. When do you do an EMG, when do you do a nerve conduction study? But you really kind of want to know what they're telling you. All they're going to do is stimulate a nerve and then see what the response in the muscle is. They're going to stimulate it, you want to see the response at the end. And then you're going to break down along the way. If there's a cold break, then you're looking at focal nerve injury. And at the far end... I'm going to skip this part. At the far end, you're going to see that the C-map is actually going to change, and it's going to take a while for the impulse to meet the muscle. And so you'll see a difference in the amplitude of the response, and you'll see a pattern of recruitment. And it does matter because when you have injured muscle and the muscle goes away, you're going to recruit nearby friends to help you out, right? And in those cases, you're looking at things that are chronically demyelinating, diffuse demyelinating, or whether or not you have just a focal injury in one pattern or something like an AITP or Guillain-Barre. So if they're telling you that... like, you send an impulse down the nerve and it's not a complete response, the muscle's only giving you half of the C-map. It's only responding a little bit. The nerve is conducting, so there's a focal neurologic injury, nerve injury, and it's AIDP. You need to move on it, okay? If it's a diffuse demyelinating process, you're probably going to have a response that's normal when the impulse actually gets to the muscle, but it's going to take a long time to get there because it's diffuse demyelinating, and those are going to be a little bit more like a CMT or chronic neuropathy. And those are chronic. You're not really going to make a move on those things. Those are going to be chronic things to stabilize and slowly see if you're able to liberate your patient. If you have an axon loss, you're just losing axons left and right, you're not going to have any response in the muscle because nothing's getting there, and so the C-map is going to be very low. There's no response in the muscle, and then you'll end up with this pattern at the bottom which is like a neurogenic pattern you can see in the middle there. It recruits what it can because it's re-innervated nearby, but there's nothing else to gain, and so when you put the C-map all together, it doesn't matter where you hit the nerve, it's not going to generate the same response down the line. These are motor neuron diseases. These are how patients get diagnosed with something like critical illness polyneuropathies, but then toxic stuff, porphyria is that type of thing, and then motor neuron disease. So when they're giving you this information, what they're trying to do is tell you the differential, and then you take that differential and you say, all right, I have a patient who's now on noninvasive ventilation. Do I have a two-week turnaround? A four-week turnaround? Can I turn it around at all? Is this patient going to get intubated and stay intubated? Should I just trach them now? And should I just send them to an LTCH? Are they going to rehab at an LTCH? Or is this potentially something I can intervene on to either stabilize or reverse? So it is an important part of the exam and the assessment, and interpreting it is difficult. It gets a little complicated, and the real assessment is going to come up next just trying to figure out how to take this information and apply it. So with that, I'm just going to give you some basics on ventilating strategies in the space of neuromuscular insufficiency, respiratory insufficiency in the ICU. So I'm a Pediatric Hormonologist within the Division of Pulmonary Medicine and Section of Sleep Medicine at Cincinnati Children's, and I'm primarily embedded in the Comprehensive Neuromuscular Center. I've been there for a while. I have no conflicts to share and a very simple agenda. Just an overview of the pathology that drives patients into the ICU with neuromuscular illness, what does escalation of respiratory support really mean, and what can be achieved prior to the ICU stay, and then some cautionary notes. So the balance of respiratory hemostasis, if I may, is maintained between optimal respiratory drive as well as respiratory power. You need both of these issues to balance your baseline respiratory loads. As soon as a patient with muscle weakness who already has some reduced power has additional insult in the form of either reduction in respiratory drive, say sedation or anesthesia, or develops an infection and is overwhelmed by secretions, the respiratory load increases and that tips the patient into respiratory failure. So, you know, we all are aware that respiratory muscle weakness does lead to respiratory insufficiency. On one side, you have the changes that take place in the lung pancreas. These include atelectasis from either low lung volume states. You should remember Laplace's law, so if you have low lung volumes, there's a greater tendency to develop atelectasis and remain that way. They also have permanent changes over time in lung compliance. On the other side, you've got chest wall deformities that come with congenital neuromuscular disorders. So again, the pediatrician in me sees children develop over time, and my goal as a pulmonologist in this space is to make sure they hit adolescents with the best possible physical form, because with good form comes good function. So if your chest wall is not well developed, they are more likely to get admitted to the ICU and or require intubations. Last but not the least, you've got background of cardiomyopathies in the background. Let's say you've got Becker or Duchenne Muscular Dystrophies, and then changes in ventilatory drive. So patients with TBI also become myopathic or neuromuscular patients. And then all of these begin to play on each other, particularly as you have a growing child. So these are examples of top rows images of patients with SMA. The first ones, someone's got rods for spine stabilization with minimal rib deformities. But rib deformities were almost the rule back in the day for SMA, particularly SMA-1. And in many cases, I find that when we convert with Spinraza, we've converted patients from SMA-1 to SMA-2 in many forms, and I feel like we should be calling it Spinraza, right? We see increasing spinal deformities and chest wall deformities. And now the lower two images on the left are the same patient. One in 2016. Oh, boy. That didn't get uploaded. So I had her image Can't see my mouse. In the lower image on the left, we have a girl with SMA-2 who has lost a follow-up. But I'll tell you what, when you look at her previous image a year and a half prior, it doesn't look that different, except that she was a little more symmetric, but her AP to transverse diameter was greater. Now that's mechanically unsound, okay? Even when you look after spine stabilization, there's a couple of things that stand out. One, again, she's got a fixed chest wall deformity because her AP diameter is greater than the lateral diameter. And the second part is there's a triangular wedge of lung on your left side which is actually immobile. You don't have any rib movement around that peninsula of lung. And that is a problem area every time she gets sick. She drops that entire load. So if you have a baseline of your patients, and because these are children, I tend to scan my patients every 12 to 18 months until the age of 4 or 5 so I have an idea of how the chest wall is evolving, and it becomes a pressing argument for me to push carphysis therapies and things like that for chest wall growth. So what are the physiologic observations, right? So one we talk about is the restrictive pulmonary defects. And so when you're familiar with this textbook image of tidal volumes and looking at your vital capacities and all your IRV, ERVs, well, you get a floor and ceiling compression on this image as indicated by the red arrows. So patients will lose the ability to take a breath over and above their tidal volume or forcefully exhale beyond their FRCs. And remember, for you to produce enough of expiration effort for a cough, you also need to produce enough of deforming forces on your chest wall to be able to produce that expiration. So when you start seeing IRV, ERV decompress, the RV generally is still well preserved until the very end. And so because the RV may be preserved, it may appear as though the RV to TLC ratio is elevated. So this is a patient who actually has Ulrich congenital muscular dystrophy. You can see the vital capacities are 30%. And severe restriction of respiratory muscle strength, both the PI max and the PE max are very much reduced. But look at the RV to TLC ratio. It's almost twice as what is to be expected. So the problem is not that there's air trapping as we would say, it's just that he has no ability to forcefully exhale to that point. So what do we see? This is a patient with Duchenne muscular dystrophy. And what do you see? I asked him to take a deep breath. And this is 100% lung capacity. His FVC was 100%. But this was an indication for me to put him in the sleep lab. If you're not moving your chest wide awake, there's hardly a chance you're going to move it asleep. And if you don't move your chest while asleep, more likely you're going to experience hyperventilation. So when you look at your patients, it's important to also understand how much they can open their mouth, how much they can open their jaw, because these are all going to be important factors for two reasons in the ICU. One, what's your nasal mask area? What's your non-invasive interface going to be? And how successful are you going to be in ventilating your patient? The patient, like you see on the image on the right, that's a girl with congenital muscular dystrophy, medicine deficient. She cannot close her jaw fully, because you can see the contact point is her third molar. So she's never been able to bite a piece of pizza with her front teeth. The problem is she's got a fixed open leak. The one on the left is an image of the I hope this works. Yes. So she's got a nice wide open airway, but look at the sliver of airway. And the problem is this patient actually came in for spine surgery, halo traction, they were doing it staged. They took off his, they extubated him and were going to put him on BiPAP, but because of his restructuring of his alignment, he lost his airway while awake and died. So understanding how critical your airway is before you start subjecting your patients to major procedures I think is an important element of understanding what they're going to do in the ICU. So what does escalation look like? Usually these patients will present either with an aspiration or maybe just a community viral pneumonia, it doesn't have to be bacterial and the secretion burden is increased. Or there could be an exacerbation of underlying cardiomyopathy as a result of which they start having water logging in the lungs. So how does compliance change? Very often patients depending on the underlying diagnosis and how well established their underlying neuromuscular pulmonary care has been they may already start increasing the frequency of airway clearance therapy at home before they call you or before they show up at the hospital. They may have extended their duration of NIV use non-invasive ventilation from just at night to extending hours in the day, maybe to 12 to 18 hours and the next maybe 24 hours. They may have added supplemental oxygen if they've had it at home to their respiratory support and I would caution that many of our families now know, particularly SMAs if they are having issues and they've got GJ tubes, they'll sometimes switch to feeding them through the J tube rather than giving them G tube feeds to reduce the gastric burden. And the patients will finally get admitted when either the secretion burden is high, there's impending respiratory failure over there, acute and chronic, or the caregivers are getting exhausted. So if you have patients that previously were not on respiratory support and show up and you are interested in starting support, there's a bare minimum you should include in your trial. You can certainly use bi-levels, you can choose to go with or without volume assured pressures volume guarantees, do what is most comfortable to you and understand the machine well as you are going to apply to the patient. Make sure you have an optimal tidal volume. Like I told you and showed you, some chest walls don't move, so listen to the patients and understand what an optimal breath for them is. Make sure you have some peep in there. Generally, five to six is a minimum, but if patients are coming with increased secretion burden, you may need to go up to prevent further lung degroupment. This whole concept of a peep of zero, I don't understand personally, but there's a group out there that does advocate for no peep in neuromuscular patients. I don't think there's much value to that. It's probably more dangerous. Pressure support needs to be over and above peep. Make sure that you match your peak pressures and your pressure support. I'm gonna give you some examples and show you what it looks like otherwise, and don't forget a backup rate. There's so many people who I see outside or hear about people getting started on S-modes in neuromuscular patients, and that's inadequate. Patients are fatigued, you need to give them mechanical breaths so that you can rest the respiratory muscles. I'm not going to get much into this except the two boxes on the right. Think of the minor settings, which include your rise times and profiles. If you go with too gradual a rise, the area under the curve, which is in this lower left box, decreases and that will actually reduce your tidal volume. Give them an appropriate eye time. Don't leave patients on this vague setting of 0.8, three seconds. Nobody breathes, inhales for three seconds. And when patients are sick, they tend to be tachypneic, their respiratory cycle time is shorter. Try and stay within physiologic limits that's age appropriate as well. Make sure the ventilator is sensitive enough for them to be able to trigger and make sure that the flow cycle sensitivity is set low so that even for a spontaneous breath, they feel like they're taking a decent volume breath. When you think about mask interfaces, pay attention to leak. Your choice of masks is often going to be delimited by what the anatomy of the face is and how much leak they can tolerate. And as you are looking at escalations and applying respiratory support, if your patient's already on non-invasive ventilation at home and they're still coming in, there's a chance they need higher pressures. Don't leave them at the same pressures for the same duration of time because you're not helping them. Watch for respiratory fatigue. Patients will, when they're finally tired, won't increase their work of breathing, but their heart rates stay high. So if your patient is tachycardic and you don't have a good reason, they're still riding the respiratory rate, one, you want to make sure you look for asynchrony, okay? Two, make sure your leak is appropriate and the tidal volumes are being delivered or guaranteed. Be careful with hydration, particularly if your patients have cardiomyopathy in the background or have heart failure. Patients who are dry, thick secretions are harder to move and harder to clear, so pay attention. Many of these patients may be dehydrated by the time they get to you, just like your asthmatics. Feeds, like I said again, like I mentioned earlier, transpyloric feeds sometimes become an advantage and minimize the risk of aspiration of gastric contents. Failures for non-invasive ventilation may either be patient-related or equipment-related. And the issue often at hand is the ventilators, home ventilators, are not capable of synchronizing with patients in extremis and you may have to, you're hitting a ceiling effect of what the ventilator can deliver in terms of sensitivity or triggers. So make sure that you match your patient's need and recognize failure of the equipment as well as their impending respiratory collapse. When you are considering intubation, your reasons for doing that would be either obviously fatigue, other issues would be increased secretion burden. Patients with severe chest wall deformities really don't have much reserve and your threshold to intubate may be lower for them. And as Dr. Luzia mentioned, patients' goals need to be kept in perspective when you're considering the intubation. So here are a few examples. Now, granted, these are sleep study epochs, but I want to bring to you a concept which I mentioned earlier, which is synchronization of your patients and matching pressure support with the peak pressures. This is a patient who's on bi-level pressures, not with a backup rate, and you can see respirations look rather, I use the word tattered because there's really a disorganized respiration, sometimes optimal size breath and very variable throughout. What happens when you add a bit of a backup rate? Now you start seeing some control breaths coming through, but you've still got some pressure support breaths in the background. So here's two things I want to share with you. One is that your patient can take a longer breath than the control, so you have a problem right there. So if your eye time is too short, that doesn't help the patient. Second thing is the patient's peak pressure with a pressure support is much lower than the pressure control. So there again, you're not helping the patient if you're telling him, I'm gonna allow you to breathe, but you're not gonna breathe deeply enough. Then when finally when the patient is optimized, granted we may obviously want a little longer eye time, your patient is gonna be riding support like this. Now, the one thing that also changed from the previous epoch, from the previous, is that you still see respiratory intercostal activity over here in the signal in brown, which you don't see once your patient is riding support. And that's how you provide respiratory muscle rest. So there's a notion out there, families will sometimes say, will my child get dependent on a ventilator if you give him support at night? I'm like, dude, listen, you go to bed at night, your arm is resting on the bed, do you wake up with the arm weaker in the morning? No, right? Good. So I want to share this with you. This is an example of complete asynchrony with this ventilator, okay? So you've got breaths in between these mechanical breaths. So your patient is breathing twice as much as what is being delivered over here. And yet, the saturations are in the mid 90s and the CO2 is in the 50s, okay? So pay attention to when you set your patient on a certain mode and assess that there's an optimal or a reasonable leak, don't walk away without making sure that the patient's synchronizing well. I'm not gonna get much in the weeds, but secretion management, there are a bunch of things available out there. There's IPPV, in exoflation, I don't wanna use the word carphysis because it's gonna be out of fashion very soon. CPT, these are all valuable options, positional drainage, partial drainage, but understand that the more you do sometimes, and you may need to, it can also exhaust your patients. I don't see a value, much value in the ICU for mucolytics. However, you sometimes may need a therapeutic bronchoscopy for patients once, if they have significant mucus plugging, once they're intubated. But we've run into this issue where patients will be on hypertonic saline, the ICU, and then they'll be starting glycopyralate because he's drooling all over the bed. So I think be careful about what therapies we use and be ready to deal with the consequences of the side effects of those. As your patient's illness evolves, you should get ready in identifying the parameters that bring you towards extubation. So have a checklist. Make sure in your mind that your patient looks, hits these boxes, checks these boxes of being afebrile, having a low oxygen requirement while maintaining reasonably good saturations in the mid-90s. The chest x-ray should be acceptable. You may have some shifting adalectosis. It may not be 100% clear for extubation. The patient should not be on recipe depressants. And remember, you need to extubate your patient from full support to full support. And what I mean by that is make sure that pressure support and pressure control breaths are optimally balanced and you have a full backup rate when you are intubated and you plan on extubating to a similar setting. So anticipate problems in your patients before they fall off the edge. Be aggressive in how you support them, but be kind. Don't exhaust them into non-areas of support. You may judiciously have to decide on an elective intubation rather than an emergent intubation. Understand the pathologies at play. If you actually have a patient who comes in following spine stabilization, this is not a patient who has active lung pathology, right? This is respiratory failure, sure, but that's iatrogenic, it's sedation anesthesia. Once you come out of that, you can plan on extubation in the ICU, guarded extubation to full support. Versus a patient who comes in decompensated because of a respiratory illness, the course in the ICU is going to be different. Understand that your ventilation strategies need to be focused around your altered pathology and your physiology. So avoid spontaneous breathing trials. You extubate your patient who's fatigued and ask them to continue to work. It's a setup for re-intubation. And so support them for both secretion clearance as well as respiratory effort. So you're going to now see, have the last two talks and Dr. Ayala will present the airway clearance therapy followed by Meredith with successful extubation. Thank you. My references. Thank you. All right, so airway clearance. Basically, I want you to know what is available out there. I want you to be able to describe what the benefits and drawbacks are of these various modalities and then think through what would be the regimen that you would use in a patient with neuromuscular weakness in the ICU. So the aims of airway clearance are pretty simple. To maintain patency of the airway, to recruit alveoli, increase lung ventilation and recruitment, and then ultimately reduce the disease burden so that you can prevent remodeling of the airways and loss of parenchyma. So triggers, things that should clue you in to use airway clearance in the ICU. Things where there is an acute increase in secretions, pretty obvious. Distorted airway architecture, so bronchiectasis underlying, so you know that they're going to be at risk for increased secretions. Foreign bodies in the airway, so tracheostomy, tracheal stents, things that increase the amount of secretions. Neuromuscular disease, obviously, because we're talking about neuromuscular patients, but many of these patients will have tracheostomy tubes and other things that will then kind of put them into a dual bucket. And then ultimately, the post-operative state as well is gonna be fraught in the setting of secretions. So starting out with mucociliary agents. Mucamyst will break down disulfide bonds. It'll reduce viscosity of the sputum. Hypertonic saline will draw fluid into the airway. Dornace alpha will actually dissolve DNA and liquefy the secretions a little bit. And alluding to what Haman had said earlier, ultimately, there is limited data for mucolytics in the ICU, kind of writ large. However, you may find it useful in the select patients. So potential drawbacks for mucolytics are kind of multifold. Anacetylcysteine, or mucamyst, actually can cause a false negative for pseudomonas. It can also impair immunoglycosides in vitro, and actually some beta-lactams as well. Dornace alpha also can worsen lung function in non-CF bronchiectasis. And all of these agents can cause bronchospasm. So please, please, please, always use a bronchodilator before employing them. External percussion. This is the tried and true cupping the hands and beating on the patient's backs. Thought of traditionally with CF, however, it can be employed with pretty much anybody who has increased secretions. Drawbacks are that it's gonna be time-consuming. It requires a skilled provider. And then the technique, because of that, will vary between providers. You wanna pair this, generally speaking, with postural drainage, because the postural drainage is gonna basically utilize the gravity effects to help you loosen up secretions and mobilize them as you are percussing externally. Just a little bit of a diagram that you can get multi-lobe drainage with various positions, and that that can be employed in the ICU. Contraindications are gonna be things like head and neck injury, if they have large volume hemoptysis or active hemoptysis. And then relative things are gonna be changes in intracranial pressure, instability kind of across the board, and then other things like thrombocytopenia. As an extension to this, then you have the external chest wall oscillator, or the therapy vest. This kind of creates, quote-unquote, mini-coughs. It's going to oscillate positive and negative pressure at the outside of the chest to shake things up. The drawback is that it does not directly augment cough strength. So when we're talking about neuromuscularly weak patients, this is not really where it's at. It may, however, be the only thing that you have at your institution, which is why I bring it up. So it's this idea that in different care settings, you may have to employ what you've got and kind of MacGyver a good regimen out of it. In which case, then, the therapy vest may be worthwhile. We have PEP therapy, so positive expiratory pressure therapy. What this does is it uses a fixed orifice that the patient is going to breathe out against in order to create some back pressure. And the back pressure, this is like pursed lip breathing for COPD patients. That back pressure is going to pop open the airways and allow for increased recruitment of alveoli and then ultimately increased secretion mobilization. The drawbacks are gonna be that this actually does require patient effort. So if you have someone who's severely weak, they are gonna be limited in terms of what they can generate in terms of that back pressure. Some examples are EasyPAP and TheraPEP. The EasyPAP is the more commonly utilized inpatient variety. Plugs into either wall air or wall oxygen and can give some flow and it can actually give some drug along with the treatment. This is essentially providing some amount of CPAP to the patient when you're using it. Oscillatory PEP is kind of an extension of this. This is gonna combine that PEP therapy, the fixed orifice and creating back pressure along with a flutter type of modality. And so here, what this is gonna do is kind of move things back and forth, scoop those secretions out of the way. And the benefits here are that it's cheap, it's accessible and they're shorter treatment sessions compared to the chest physiotherapy. Drawbacks are that it's going to rely again on the patient to generate that flow. So again, in the really weak patient, you're probably not gonna employ these devices. Our institution uses the Acapella and the Arabica but some of these other ones also exist, the Cornet and the Quake as well. So then we get to some of the mechanical versions where the patient does not have to generate things directly. And so this is intrapulmonary percussive ventilation or IPV. This is continuous and oscillatory positive pressure that is in line with a nebulized fluid. So this is your metaneb if you have that modality at your institution. And so what this does is, the beauty of this is that it combines multiple treatment modalities into a single treatment. And because it is inflating the chest, you will get some alveolar recruitment and mobilization of distal secretions which are often the issue in these neuromuscularly weak patients who have kind of micro-adalectosis over the course of the day because they're neuromuscularly weak and cannot expand their chest wall sufficiently. Drawbacks are that the patient may not tolerate higher flow rates with this and that it can be difficult to get for home use. Although sometimes if you can say in your notes, the patient has not tolerated mechanical insufflator exsufflator, they'd have benefited reliably from metaneb or whatever you're using as IPV, and that is a way to potentially get them qualified. So some examples of metaneb is the Hilram variety of IPV that is available for inpatient use and then their home use version is called the Volara that you can see on the right there. Then we get to our tried and true mechanical insufflator exsufflator. This is the one that you will often, at least at our institution, you'll hear people call it Coughasus. Coughasus was the proprietary name for the Philips or Spironics device. It is no longer being made or serviced, word to the wise, do not ask for it for your patients. They may still have it at the DMEs but they will not be able to get serviced so you are better off going with a different modality. The benefits for mechanical insufflator exsufflator is that it applies both positive and negative pressure to truly augment the patient's native cough strength. So what it will do is it's going to insufflate the chest at anywhere from, I believe it is all the way from 10 to 50 centimeters of water pressure and then it will pause for about two seconds and you can set the time duration and then it'll actually exsufflate or suck at the negative version of that pressure. So ideally you're gonna have the patient interacting with this and engaging with the therapy such that they're able to generate whatever cough they're able to generate with their native cough force while it is exsufflating so that you actually get an augmentation of their cough strength and increase mobilization of secretions. Potential intolerance will come with patients who have had chest wall fibrosis over time. You're catching them late in the game and everything is kind of scarred down so they're not as able to expand their chest wall so when you hit them with 50 of pressure, they're gonna be like, ouch, you know? And it's real and it happens. Your frail little ladies probably are also gonna be the same type of patient where they will not tolerate the higher pressures and so you are within your rights to go way down and just kind of walk them up into what is tolerated. Finally, also, you wanna be very aware that if they have bulbar dysfunction, there are kind of multiple issues that they may run into, one of which is that with bulbar dysfunction, they may not be able to form a good seal at the mouth so that you can't reliably use a mouthpiece oftentimes and you'll have to use a mask. Similarly, with bulbar dysfunction, they can actually get glottic closure probably because their posterior oropharynx is spastic and if it's hit with a big amount of pressure all of a sudden, it'll actually cause the glottis to close. So just be aware that that may be an issue to run into. So the devices that are currently on the market are the Biways, the Sinclara, and then I put the Voxen up here as well. Voxen is a ventilator that actually, the C in Voxen is cauphasist. So that is a ventilator, oxygen concentrator, cauphasist, suction, and nebulizer. The beauty of this is that if you have that at your institution and you have a patient on it, you can do the cauphasist in time with ventilation. You do not have to stop ventilation in order to give them a cauphasist. And we've had a lot of success with that. So thank you all very much and Dr. Greer is up next. All right, hi y'all. I'm gonna also go through this rapidly so hopefully in the last 10 minutes we can get our patient extubated. All right, I have no conflicts of interest. My name's Meredith, I'm at Emory. Same thing we all do, pulmonary current, sleep, and neuromuscular disease. So today I'm just gonna get through four topics. The first is three basic principles of extubating a patient with neuromuscular weakness. The second is some of the barriers that can prevent that from happening. The third is how do we evaluate people readiness for extubation and some strategies for that. And then the fourth is who's not gonna get extubated and we just need to commit to tracheostomy. So let's talk about the three principles. So the first principle is basically that normal SBTs are not gonna work for our patients because our patients are not even spontaneously breathing all the time on their own. The second thing is that it's important to identify their underlying disease so that you can understand its natural progression in order to choose the extubation strategy that's gonna work for you. And then finally, as many of us have alluded to, the goal is not to be independence. It's to be non-invasive. So the whole goal here is to go from invasive to non-invasive ventilation, not to get somebody liberated from a ventilator. So what are some of the barriers to that? So as we've already talked about, optimizing the patient is key. So a dry lung is a happy lung, we all know that, but also for us, a clear airway makes us smile. So you have to have a clear chest X-ray. Your gas, most of these patients are coming in with hypercapnic respiratory failure, so you want that to be improved. And then your oxygen should be about 92 to 95% on 21%. If that's what they came in on. Our patients generally, unless they're in stage fibrosis from chronic atelectasis, do not need oxygen if you are appropriately ventilating them. If they have inability to clear their secretions and are having choking and aspiration despite having all three of these things, then they're gonna get re-intubated and they are not ready to get extubated. And sometimes that's just because they're having residual secretions from RSV or a pneumonia. Sometimes it means that their bulbar disease has progressed and they're unfortunately gonna have to have a trach talk. We already talked a lot about clearing secretions. I'm just gonna reinforce that. Mechanical and exhalation, manually assisted nebs, the vest, and I think you said bronc if necessary, is so important. You just gotta clear those airways out for them before you are getting ready to put them on a mode that's gonna go home with them. And then additionally, optimized mechanics. For some of these patients, if they have the comorbid cardiac conditions, they may end up having volume overload. You may need to do thoracic and TCs because anything that's sitting on the pleura is gonna further compromise their ability to utilize their diaphragm, which is already weak. So one of the things I like to talk about that's really important, more important, dare I say, than the cacophysist, is to talk to the family. Because if you do not have a plan with that family and that patient before you extubate them, then things are not gonna go well for anybody. Somebody yesterday said when you trach a patient, you trach a family. And I think it's really, really important to think about that. And you wanna have the conversation with the patient because they're gonna be interacting with you as well as the family and have it in the bedside while they're intubated. They can write to you, they can text. A lot of our patients will have eye, gaze, and be able to communicate that way. The questions are gonna be, if we extubate you and you need 24-7 non-invasive, did you come in on that and do you know how to do that? Or is that gonna be a new thing for you and are you even gonna be able to do that? Because that's really hard to start straight out of the ICU. And then the second question is, what if you don't succeed at staying extubated? Do you wanna be re-intubated? Because some patients, while they may have come in full code do not wanna go through this again and they do not want that tube back in a second time. And the last question is, have you thought about tracheostomy? Hopefully, if any of y'all see these patients in your clinic, you've talked to them about tracheostomy already. But as you stated, a lot of patients get diagnosed in the ICU and so you in the ICU may be the first person having to have this conversation with them. So what are the extubation strategies that we're gonna use? So we go back to our principles. And remember, we said that traditional SBTs are not generally gonna be the way to go. So what parameters do we look at? Historically, we've had clinical evaluation and then we've memorized numerical evaluation. And I'm actually gonna not talk about those numbers because I think going to the bedside and looking at the patient is far and away more helpful. So again, you want your chest x-ray clear, you want secretion volume and handling to be acceptable. And if the person has already had a suction machine at home, then having some secretions is fine, but not the kind where the nurse can't leave the room. And then are they comfortable on the weaning mode of choice? So you wanna choose a mode that you're gonna wean them on that's gonna mimic the mode they're gonna have on their home ventilator. So the second principle was underlying disease, right? Identifying that. And again, a lot of muscular disease is the same and you've heard about a lot today. Some of what we do isn't even weakness, it's just chest wall deformity. So we're gonna break this into acute and recovered versus chronic and home, non-invasive. So acute and recovered, the most common is gonna be myasthenia and Guillain-Barre. And then the chronic is gonna be patients with spinal cord injury, muscular dystrophies, ALS, and then ICU-acquired weakness. And of course, there's many other, but these are just some of the common examples. And you're gonna think about these totally differently when you're weaning. When you move toward extubation, you know you have all these kind of modes, right? And the acute and recovered patients, you're gonna treat them just like any other acute and recovered patient in the ICU, and they can be weaned by TPs, CPAP, pressure support, and these are all spontaneous modes, right? For the chronic patients, you can use a variety of modes. So I'm not gonna talk too much about SIMV today, but for those of you who work with patients with spinal cord injury, we often wean them on SIMV so that they can have the sigh breath component. But pressure support is something that you can use. You just wanna not do 5 over 5, right? Because you're not gonna send them home on BiPAP-S 10 over 5, okay? So you can use it, just know that you don't have a backup rate, right? And that's where sometimes putting them on a PC SIMV mode with like a little backup rate is gonna be more likely to mimic kind of the BiPAP setting that they're gonna go home on. One important thing that we really wanna say is trigger high, cycle low. That's kind of like our mantra. And so when I say trigger high, I mean your sensitivity is gonna be high. So instead of that three liters per minute that they need to take a breath, it's gonna be like two or even one. And then cycle low is the percent peak flow that the breath will end at. So on a conventional ventilator pressure support trial, it's set at 25% the peak flow. And so that may not be enough if your patient has a weak flow because they're weak. So you may wanna set it at something like 15 or 10% of the peak flow to give them the longest and easiest breath that they can get, okay? You can also use control modes. I think many of us have patients on things like PC AVAPs and things like that. So you can put them on PC or VC and then you can extubate them and their Trilogy or Astral will have the same mode. So what are we gonna extubate to? So I have two minutes. I'm gonna go through this real quickly. So you have support modes with a backup rate and then you have a hybrid mode and then you have a control mode. This is sort of the little volume curve just to show you that it's not only pressure that gives you the area under the curve for volume, it's time and I think we've already said don't sleep on those minor settings of the trigger, the rise time and the cycle and that's because we wanna improve the area under the curve. So for BiPAP ST and for VAPs, it's important to remember that the IPAP or the pressure support, it stops based on flow cycling just like we said. So you wanna set the percent of the peak flow low so that they get the longest breath. You also want to remember that the spontaneous breaths are all gonna be flow cycled. So if you set an eye time, that is only applied to the controlled breaths and not to the spontaneous breaths. On some brands, by some brands I mean ResMed and now the Evo, you can actually set a min and a max eye time that applies to those spontaneous breaths. So that's a really important setting to look at because the factory defaults .3 seconds and that is way too low for a minimum eye time, okay? So you wanna put that somewhere closer to one, 1.2, we'll even go up to 1.5 seconds in some patients and that way their breath, even if it's spontaneous, if it's not a big enough flow to get them into that time range, the machine will help push them with that time you set and they'll have a safer, longer breath and this is the whole goal of avoiding rapid shallow breathing, right? I'm not gonna talk again too much about SIMV at all but for spinal cord injury patients it can be helpful and then PCVAPs is something that you can use in your very, very weak patients who really need full control of their breath but you wanna volume target them. Keeping patients extubated, again, airway clearance and then sip and puff or mouthpiece ventilation. If you haven't heard of this, I encourage you guys to Google it, look it up, read about it. So many of my patients have had a huge change improvement in their quality of life by being able to use sip and puff or mouthpiece ventilation and not having to wear a mask 24 seven. And finally, who just needs to get trached? So 78% of patients with Guillain-Barre are gonna need ventilation more than three weeks and so early tracheostomy actually in that cohort is recommended because they can start rehab, walking around the unit, rehabbing their extremities while their respiratory muscles are still healing and it doesn't mean that they can't get decannulated in the future so that's like a completely different family talk than one you may be having with a patient with ALS. Myasthenia is kind of the opposite. They can look like they're gonna get better quickly but then they can fail again quickly and those patients doesn't mean they need to get a trach but it may take a couple tries for them to successfully stay extubated. For the chronic patients, it's just bull bar disease and secretions and that's what I tell my patients and their families. Once I can't control your secretions anymore, I'm really gonna have to put this tracheostomy tube in if that's something you want which goes back to the whole conversation that you need to have with them. So I think the most important intervention to the patients with the chronic and progressive neuromuscular diseases is actually the family conversation. So in summary, hopefully from this you learned to understand the physiology is really important in deciding what you're gonna do from beginning to end. The biggest barriers to success is gonna be those secretions and you need to utilize your airway clearance therapy. The goal, please please remember this, we remember nothing else, is not liberation from ventilation, it's just to get from invasive to non-invasive, to get extubated and stay activated. And finally, that people with Guillain-Barré and with bull bar disease may need tracheostomy and the family discussion is key. I went one minute over but thank you guys and we'll be up here for questions. Thank you.

neuromuscular weakness

ICU

evaluation

management

respiratory failure

intubation

non-invasive ventilation

reassessment

ventilation

extubation