Good morning, everyone. Thanks so much for coming to our talk at 8 a.m. on the first day of the meeting. That's great. It's my pleasure to introduce my friend and colleague, Dr. Mike Hare. No, you're not seeing double. Who will talk about the, Mike's a professor of neurology at University of Vermont. He's gonna talk about the respiratory complications of neuromuscular disorders, and then I'll pick it up and give a talk on the cardiac abnormalities in neuromuscular disorders. So thanks again for coming. Appreciate it. Make sure this is working. Perfect. All right, yes, thank you, everybody. Thank you to the AANEM for inviting us to do this session for a second year. So thank you, everybody, for coming at 8 a.m. I hope you're all awake. P.m., AANEM, what did I say? AANEM, very sorry. 8 a.m., first day. So we're gonna talk a little bit about respiratory complications of neuromuscular disorders. We all see patients who have muscle weakness related to their neuromuscular conditions. So I'm gonna talk a little bit about muscle function. These are some things that you may already know, you probably already know, but I wanted to sort of go over things so that we're all on the same page. We'll talk about the tests that we use in our clinic. We'll talk about some of the conditions that can impact breathing, and then we're gonna talk a little bit about how some of the novel treatments that we have are impacting respiratory function for our patients. So just to sort of frame everything, I think it's important, we think a lot about skeletal muscles, but we often don't think about these skeletal muscles that much. But just to frame it, so the muscles that we use for breathing, so the diaphragm is the workhorse of breathing, and it has both type one and type two fibers, and it has a rich vascular supply because it's such an important muscle. And it's the muscle that we most rely on when we're sleeping at night, which is why when it becomes involved in these conditions, it can be a big problem for our patients. And then we have secondary muscles in and around the ribs that can help expand the chest. And then I think the often forgotten muscles of breathing are the bulbar muscles, and being somebody who sees a lot of patients with myasthenia, this is really important for our patients, because if you're collapsing the upper airway, it makes it difficult to breathe. So there's sort of three big ways, or four big ways that you could get neuromuscular respiratory weakness. So the first is, and the most common, is restrictive lung disease. So this is where it's hard to expand the chest and hard to exchange gas. And this most presents with accumulation of carbon dioxide first, rather than hypoxia. And while the people in this room know that, our colleagues in the emergency room and our colleagues in internal medicine and family medicine and pediatrics don't recognize that as much. They will often put a pulse ox on some of our patients who are coming in, who are having breathing trouble, and they'll mistake a high oxygen level for working respiratory function. And we know that that's a late complication of these conditions. Then you can also have insufficient respiratory clearance because of poor cough, which can result in pneumonia and infection, and then bulbar dysfunction resulting in upper airway collapse. And this is just sort of recognizing this in a different way. So on the left, this is all things that contribute to ineffective ability to sort of expand the chest. You can develop dysphagia and bulbar dysfunction, which can cause collapse of the upper airway. And then, hmm, missing from my slide. The other one I put up, I believe, is over here. Some of our conditions also cause interstitial lung disease so thinking about things like inflammatory myopathies and synthetase syndromes, which can also affect gas exchange. And I've actually, when I think patients have myopathy, it's important that you order some measure of gas exchange when you order your pulmonary function studies because the pulmonologist won't always do a gas exchange, a DLCO study, so you have to order that separately often at many institutions. So how do you know when your patient's starting to have more respiratory dysfunction? So sometimes people will just tell you that they're feeling more fatigued or more weak. The other muscles seem to be working less well. Some of our patients will report that they feel short of breath. It's important to ask them in what situations they're having shortness of breath. So if it's at rest, it suggests that the respiratory dysfunction is starting to become more severe. And then if they're having it when they're laying flat, it suggests that it's even more severe. And when we're laying flat, we're relying a lot on our diaphragm. And in our patients who have neuromuscular weakness, it's hard for them to expand their chest in the supine position because their muscles really have to fight gravity in that position. And then our patients will often tell us about morning headaches that can often be a clue or fatigue during the day. Things that we can look for at the bedside. So you can look for increased work of breathing, use of accessory muscles. You can get paradoxical breathing where the stomach starts to come out and in when you're breathing. You might see distention of neck veins very late. And often our patients, just as this becomes more severe, just look really uncomfortable and labored. It's often not that subtle when the respiratory function becomes really affected. So these are some things that you can do at the bedside. I always talk with our residents and fellows about having things that they can test, that they don't have to rely on someone else to test, especially when a patient with Guillain-Barré syndrome is coming in at night. These are things that a resident could assess at the bedside and things that they could assess four hours later if they get a call from the nurse. So one test that we use a lot in myasthenia can also be helpful in Guillain-Barré is just a single breath count where you have somebody take in as much air as they can and count out loud at one number per second. The average adult should be able to get to about the number 30 before they have to take a breath. You can look for fatigable dysarthria, which we do in myasthenia at the bedside. So you have a patient count out loud, whoops, to 30 or 50 and see if they're starting to develop dysarthria. Something that tracks really well with the need for intubation or positive pressure ventilation in a hospital setting is having a grade three neck flexion strength. And you really have to check your patients in the supine position. If they can't get their head off the bed, that's worrisome. We did a small analysis of some of our patients that were in the international GBS study at UVM. And, whoa, my, huh, my animations are not working. That will be fine. So if we had our patients in that study, if they came in at baseline and their neck flexion was less than three, 75% got intubated. And then if they dropped below a three at any time during their hospitalization, they wound up getting intubated. So those are things that you can check and things that your residents and fellows can check at the bedside. And it's good because these tests need someone who can work a machine. So you can have a respiratory therapist do pulmonary function studies for us. The number that we focus the most on in neuromuscular medicine is the forced vital capacity, which is the amount of air that you can take in, maximal amount of air that you can take in and blow out. And the amount of air that you can take in and blow out is related to how big you are. So it's scaled by how tall someone is. And based on height, we can have percent of predicted and the average person who's not having a neuromuscular problem should be able to be at about 80% to 120% of predicted normal. We can also check inspiratory and expiratory pressures, which are ways to see how forcefully you can push in and suck in air, which is a good measure of cough function. And these are important tests. You can get them as an outpatient and you can get them as an inpatient. One thing that I will recommend is that you work with respiratory therapists who are comfortable with using a mask for these procedures when needed, because if our patients are having bulbar weakness, it's hard to seal on the tube and you can get false reductions in these numbers. So to be accurate, it needs to be done with a mask in many patients. Oh, I see what happened. These are the wrong slides. They loaded the wrong slides for me last night, but that will be fine. We're in the right place. We're in the right place, wrong slides. Thank you, AANEM. So this is a breathing test, which I updated, but so this is a force vital capacity of somebody who's starting to have respiratory dysfunction. And you can see in the report, you get an actual number. So this is 2.2 liters, which winds up being 75% of their predicted. So they're just starting to drop. I wanted to show you here. So often when you send patients for pulmonary function testing, it's important to tell the pulmonary team that you want a supine value as well, because there's a couple of ways that you can qualify your patient for positive pressure ventilation. And one of the ways is if somebody's at 75% of their predicted, they wouldn't qualify by insurance for using a BiPAP, even though they may need it clinically. So if you check them in the supine position and they drop to 60%, you could qualify for a BiPAP. Or if you drop by 20% from seated to supine, you can again qualify for positive pressure ventilation. So it's important to do the dynamic testing at our center. I just put this up because in our center, they report our supine studies as post-bronchodilator, which is fantastic. But they usually write it in the report that they did this for us. The other thing in this patient is we did mean inspiratory and expiratory pressures, and this person was sort of starting to be at the 40th percentile or so. So this is kind of how I think about the conditions that affect respiratory function and neuromuscular disorders. So there's chronic progressive conditions like muscular dystrophies or congenital myopathies, congenital myasthenic syndromes, SMA, ALS. We have things that are more temporary because we have treatments, and these are autoimmune conditions. And then increasingly, there's a group in the middle that I think is really important to recognize. So these are patients where previously, they were over here, and now as we're starting to have more treatments are really falling into the chronic treatable section. I wanted to add in here, this year is the congenital myasthenic syndrome. So because we have treatment for some of those conditions, you can actually impact their respiratory function quite a bit. And I just saw one of my favorite patients with a congenital myasthenic syndrome last week, which is why I updated my slides. And he, for years, had been diagnosed as limb-girdle muscular dystrophy and had been written up in the New England Journal of Medicine in the 1980s with his father as having had a limb-girdle muscular dystrophy, but never had genetic testing. And then I met him for the first time a few years ago, and I said, well, we should probably just do some genetic testing. And it turned out that he had slow-channel congenital myasthenic syndrome, which is very treatable, with Brozac, fluoxetine. And when I met him, his forced vital capacity was at 40% of predicted, and he was using a BiPAP. And we started him on fluoxetine. He was also in a wheelchair and couldn't stand. He works as a, he's a preacher. He couldn't do his job. And we started him on fluoxetine, and suddenly he was running, standing at his podium at work, and his forced vital capacity was at 80% of predicted. So it's very important to do genetic testing for our patients, because sometimes you find something that's in this box, and the improvement can be dramatic. And then it's important to recognize that a lot of our myositides can generate interstitial lung disease, and we treat some of our patients with methotrexate, which can also result in interstitial lung disease as a side effect. So no matter what patients I'm treating, epilepsy, neuromuscular, it doesn't matter. This is what I think about when I think about how we're gonna take care of our patients, and it's really about helping them have a better life. And I think my mentor said it best. So with respiratory decline, as we're trying to support our patients, it's really important to have a team so it's not just the physicians, but it's a nurse, it's a social worker, it's a pulmonologist, it's a respiratory therapist. And at home, families and caregivers really play a big role in helping patients who are having respiratory dysfunction. They're the ones that are often managing some of the support devices that we have. This is just a smattering of different devices. So these are masks that could be used with positive pressure ventilation, this is a cough assist device, which is used to force air in and suck air out. And I think it's important to recognize that vaccines are a treatment for respiratory decline in neuromuscular patients. So I think multidisciplinary care is really important for figuring out who's having this trouble. It's important to start discussing these things early so that you have time to plan any interventions that you might be doing. I also think it's important to get palliative care involved early and I'll show some slides about that as well. Vaccines are important. RSV has become available for adults. Pertussis on the diphtheria, tetanus and pertussis vaccine is important to keep up to date as well. And then as people need more support, we think about positive pressure ventilation, secretion management and radiation. Positive pressure ventilation, secretion management in rare patients, sometimes ventilatory support. Something I'm gonna talk a little bit about later is the idea of using a cough assist earlier in the care of some of our neuromuscular patients. To qualify for a cough assist device, these are some of the, I'm sorry, this is for qualifying for positive pressure ventilation. You can see peak inspiratory force of negative 60, an oxygen saturation below 88%, force vital capacity below 50 or 60%, depending on which insurer you're working with. And then to use a cough assist device, it's usually if you're able to exchange less than 270 liters per minute. So how do our patients do? And it really is sort of dependent on which condition we're dealing with. So this is a nice paper that was done and it was talking about some of the differences between, I'm gonna call it positive pressure ventilation. I think it may not be appropriate to call it non-invasive ventilation because sometimes it kind of is invasive to have a mask on your face for hours during the day. So I'll call it.

respiratory complications

neuromuscular disorders

cardiac abnormalities

muscles used for breathing

multidisciplinary team