Understanding Restrictive Pulmonary Disorders

Okay, now we are starting the last PowerPoint presentation, the last chapter, chapter 23, for the respiratory unit, and it's the restrictive pulmonary disorders. So remember, we divided pulmonary disorders into two broad stroke conceptual categories. The first was obstructive pulmonary disorders. Those are, we can get the air in, but we have a difficult time getting the air out. Restrictive lung disorders operate very differently. They're antithetical to the obstructive lung disorders. With restrictive lung disorders, whatever air is inside, we can get out. We just have a difficult time getting the air in originally. So that's the conceptual difference between the two, and we're talking now about restrictive pulmonary disorders. And yeah, there's 181 PowerPoint slides, but we're not covering anywhere near all of those. That's good news. Also good news, it's the same doggone inflammatory response that works that brings about the damage here, but we're going to talk about that. So generally speaking, how is it that there can be decreased lung expansion? So either there's a change with the lung tissue itself, the lung parenchyma or interstitial tissue. There's a change with the pleura that surround the lungs. There's a problem with the chest wall itself, or there's a problem with the neuromuscular junction or neuromuscular function, and we'll actually talk about that specifically. So the capacities, the next slide, the capacities that we talked about in terms of the four lung capacities and four lung volumes, what they were for obstructive disorders, they are the exact opposite for restrictive lung disorders. In restrictive lung disorders, we have decreased vital capacity where there is increased vital capacity. There is decreased lung capacity, there is increased in obstructive. FRC here and residual volume are lower compared to what they were in obstructive. lung disorders. So the other thing that's really interesting is the arterial blood gases. So remember, with restrictive lung disorders that are exactly the opposite of obstructive lung disorders, we can't, whatever error we have, we can get rid of. And that accounts for, conceptually, why there are normal or even decreased levels of CO2 on the arterial side, because whenever we have to blow off, we're able to blow off. The issue is we can't expand to get air in. And so what does that mean? That's where we get the decreased arterial O2 levels. So on the next roughly 10, 12 slides, I am, you're not responsible for fibrotic interstitial lung disease. nor diffuse interstitial lung disease. What I'm going to do is I'm going to use these two as an explanation for what happens in all restrictive lung disorders, regardless of whatever the etiologic agent may ultimately be. So whatever it is that happens, there is damage to the alveoli, the epithelial cells, the single... simple squamous epithelial cells, they're lying the alveoli, or there's damage to the capillary beds that are served by the alveoli. When there's damage, the walls get thickened, ultimately, in the interstitium and the alveolar walls. And what happens is with repetitive damage, as there is repetitive damage, we have repetitive inflammatory response. And when we have constant inflammatory response and damage, ultimately we do what? We deposit collagen to try and buttress the tissue that was harmed. So inflammatory response gets started for reasons that we're going to talk about. It brings about damage to the alveoli, to the alveolar walls, and to the capillary beds underneath. And ultimately... that causes those to become thicker and we deposit protein structure, collagen, to reinforce those as well as the interstitial lung tissue, which is where the alveoli are ultimately parked in. In that process, what we've done is we're depositing fibers in tissues that are supposed to expand or move and are not supposed to be weighted down with extra fibers. So what is restrictive lung disorder? we've lost the capacity to expand our lungs. Why? Because regardless of the particular process that's at work, that started the whole thing, the inflammatory process causes damage to the alveolar walls, to the capillary beds underneath, and or to the interstitium that's behind, or that the alveolar walls are a part of. And there's enough damage and enough inflammatory process activity going on that ultimately collagen reinforcement gets deposited. And when collagen reinforcement gets deposited, we lost the expandability of the lung tissue. We reduced the lungs'compliance. So the lungs can't ever fully open, and they can't ever bring the right amount of air in. But that's why whatever's in can go out. So briefly, let's turn to slide 11, and I'm out. What happens? Well, there's progressive dyspnea with exercise, and these people desat. It doesn't matter which particular restrictive lung disorder that we're talking about. You get somebody in a pulse ox, and you have them exercise. If they have an established, well-entrenched restrictive lung disorder, when they exercise, they're never going to benefit from exercise. When they exercise, because they can't bring in enough oxygen, O2, their lung expansion capacity is permanently compromised because that's the case. Instead, they use up their O2 stores, they just desat. And that's obviously disastrously bad. Often, people who have restrictive lung disorders have a non-productive cough and it's irritating because they can't ever clear the mucus that's deep within out. And why is that? If you can't bring enough air in and the lungs are not sufficiently compliant because now there's fibrosis at work in the lung tissue, then you can't generate enough pressure, the 100 millimeters of mercury pressure, to be able to clear what's inside. These people tend to have end-expiratory crackles or RALs. It's literally like taking two pieces of Velcro that are attached to each other and prying them apart from each other, that's what you can hear in advanced restrictive pulmonary disorders. And why do they have anorexia and weight loss, slide 12? Because they spend so much ATP on the work of breathing, trying to get every extra cubic centimeter of air to come into the lungs. With restrictive lung disorders, the... Chronic ones, some are acute like pneumonia, but in the chronic ones, exercise does not allow the person to be able to increase cardiac output. As a matter of fact, exercise is actually very bad for them. So let's go to slide 15, treatment, get people to stop smoking. Why? Because that's an inflammatory process triggering event. Every single inhalation of any substance triggers the inflammatory process, the one thing we don't want happening. If they got the restrictive lung disorder because of exposure to certain environmental irritating factors, we want to remove that from them. We give anti-inflammatory agents. Why? Because we want to dial down the inflammatory response. which is the reason why we do immunosuppressive agents, because when we're talking about the inflammatory response, we're really talking about an immune system response that is actually so harmful it's causing lung damage. Do these people qualify for lung transplants? I don't want to say anything at all about transplants, period, so I'm not going to respond to that. Okay, so sarcoidosis, slide 16, happy times. I'm not covering sarcoidosis. I know that there's a prevalence of sarcoidosis in this state, but I don't want you guys to waste any time learning about it. So slide 26, hypersensitivity. Pneumonitis. Pause. Pneumonitis, inflammation. Hypersensitivity is just from patho1 the way the disease process or the mechanism of injury is affected. So another way to refer to hypersensitivity pneumonitis is extrinsic allergic alveolitis. So what is this? The alveoli get inflamed because of something that they're very sensitive to. That's what it is. It's primarily found in people who've never smoked, and it can be an occupational disease as well. So let's just briefly look at slide 27, farmer's lung. So until relatively recently, where the cabs of tractors that farmers sit in as they go over cornfields, soybean fields, whatever it is, they used to be open, and farmers inhaled a lot of particulate matter, and that's how. farmer's lung came about. Bird fancier's lung. So I'm not trying to rain on anybody's parade. I'm going to say this though, anybody who has a pet bird or chickens, if you are remotely possibly inhaling anything that comes off of them, no, no, Jim, we have, you know, we lay down protective stuff around the cage in the house, et cetera. Yeah. Guys, if it's in the house, that means it's aerosolized. You are at risk. So pet birds and chickens all can cause bird fanciers'lung, which brings about the restrictive pulmonary disorders I began this lecture with. People who love to go hunt for mushroom and get mushroom are people who make cheese. Cheese makers'lungs, shout out to the Aaron Rodgers fans in the world. I'm no fan of Aaron Rodgers. I'm from Chicago, after all. But cheesemakers, same thing, particulate matter. Grain handlers, lungs, same thing. Pituitary extract hypersensitivity. Yeah, so a lot of people are taking a whole lot of health food concoctions and energy formulas and special concoctions, sometimes with pituitary extract in them to get their muscles to be bigger. That's all I'm saying. Fish, meat, workers, lung. When we had an NFL season and games happened in Seattle, they would always show before the game or during commercials, on the way back from a commercial, back to the game, when the Seahawks were playing, they'd show fishmongers at fish markets throwing fish to each other for the sake of the camera and to chop the fish head and tail off and to package it up for the customer. Those are fishmongers. Yeah, they inhale all kinds of things that can... destroy their lungs. And then humidifier lung, pause. Thermophilic bacteria, amoeba and fungi. Notice what causes it. Humidifiers, hot air humidifiers, so things that make the water hot, and then evaporative coolers, also known as swamp coolers. But Jim, my response, next slide. So I want to say there are a couple things about hypersensitivity, pneumonitis, that sometimes confuse students. So the first thing that I want to say is that we have antigen antibody complexes. So they get formed, they get wedged in the tissue, that antigen antibody complex causes destruction to the tissue, which triggers an inflammatory system response. That's how that happens. Okay. Now notice it says on this slide type 3 hypersensitivity reaction. That's a B-cell hypersensitivity reaction. But then we can also have on slide 29, it says a type 4 reaction. Right. So hypersensitivity pneumonitis can be triggered as a type 3 B-cell mediated hypersensitivity reaction or a type 4, which is a T-cell mediated hypersensitivity reaction. In the type 3, antigen antibody complexes get stuck in the alveolar walls, and then we have the inflammatory process. In type 4, we have granulomatous inflammations that happen. So the symptoms on slide 30 for acute hypersensitivity pneumonitis as opposed to chronic. For acute, the symptoms start relatively shortly after exposure. four to six hours and they resolve and about a day later And what are the symptoms? So myalgias, pain, weakness, sweating, chills, like they're sick, headache, malaise, lethargic because of lack of oxygen. And when you talk to one of these people, you get a patient and they come and they say, you know, it's really weird because all week long I have these symptoms. But for crying out loud, by Saturday night, Sunday morning, I'm actually feeling a whole lot better. You ask, do you work over the weekend? No, I don't. What do you do for? a job and they tell you, boom, you just discovered the reason why they have hypersensitivity pneumonitis. So respiratory symptoms, there's a dry cough perhaps, but they're breathing rapidly. Why? If you can't expand the lungs, you still have to do four liters of alveolar ventilation a minute if you're going to get the right oxygen amount. So what does that mean? If you can't take a bunch in with each cycle, well, you got to have more cycles. So that's where the tachypnea comes in from. Chest discomfort because there's not enough O2 in the inflammatory processes at work. And then dyspnea at rest, so they can't breathe well. Well, obviously, because the lungs can't expand. Intermediate, so as this is developing, there is a cough that sets in that remains as the fibrosis sets in, as the deposition of collagen fibers. begin to set in. And then there's persistent dyspnea and fatigue. Eventually, the fibrosis in the pulmonary interstitium causes a dramatic increase in the resistance in the vascular supply, pulmonary vascular supply, and that, of course, works itself out and abuses the right ventricle so that core pulmonoly ultimately happens. In chronic hypersensitivity pneumonitis, You do an x-ray and what do you see? Even the upper lobes are completely filled with fibers, with scar tissue basically. And that's it. That's disastrously bad. There's no turning around from that. So skipping to slide 34, what's the whole point of skin testing? Well, if you suspect hypersensitivity and pneumonitis, you need to be able to tell them what to avoid. And you have to figure out what that is. That's why you do skin testing. You might see increased, depends on when, after they have symptoms, if they've been around recently, the thing that's triggering it or not. But if they're around the antigen at the time that you actually do the blood draw, then you're going to see elevated WBCs, not necessarily neutrophilia, but elevated WBCs, and you're going to see potentially drop as it's working itself out a drop in O2 sats and the pulmonary function test PFTs are all going to be the same that they're going to be in every restrictive lung disorder so you identify the agent and hopefully you remove it and why do you give oral corticosteroids because that dials down the inflammatory response so the next category slide 36 occupational lung diseases. So there's a lot that's here to summarize in a succinct, hopefully succinct fashion. So how do people get occupational lung disorders? Well it all is up to whatever the gas or gases and or particle or particles are that they're inhaling while they're at work. And the bottom line is that atmospheric pollutants have a really huge effect on people's lungs. So that can cause lung damage to begin, and then they go to an occupation where they have some particular gas or particle that they're dealing with that exacerbates a lung disease that's been triggered by atmospheric pollutants. So I don't care about any of this stuff on slide 37. I just want to point out cigarette smoke is on there along with photochemical accidents for those who like to develop their own films. And we're going to, slide 38, we're going to give a term of art, a general medical name to all occupational lung diseases, no matter what kind they are. And we're going to call them, the name of that first bullet point, pneumoconiosis. And, pneumoconiosis, plural, those are just occupational lung diseases, and they are caused by inhaling, and it's important, it could be a gas, but often it's an inorganic dust particle. Why is it important that's inorganic? Because if it's inorganic, that means our body simply can't process it. And when it gets in, it causes damage. And obviously, the greater the exposure, the longer the exposure, the worse the consequences are. You do not have to know anything at all about anthracosis, silicosis, or asbestosis. I've already named those a few times. You don't need to know them. What I'm going to tell you is that they all have very characteristic... crystals with particular geometries. And here's what happens, and here's what happens in general to restrictive lung disorders when our alveolar macrophages take in something that they can't handle. So we get some crystal, and there's stuff you do have to know. You get some crystal that goes in the macrophage, the alveolar macrophage, it attempts to process it, it can't. So it jettisons out. that crystal structure where does it jettison it to the pulmonary parenchyma or interstitium the main lung tissue when it gets there there is an inflammatory response that's triggered and we also that's bad and then we also have the deposition of a crystalline structure um that gets stuck into the parenchyma that's never going to leave and so what do we have we have collagenous fibers and then these crystalline structures being deposited in the lung parenchyma that's making the lungs fibrotic, they lose their compliance, their elasticity, can't expand, can't get air in. If you've ever seen pictures of coal miners'lung, and I don't know if I, I don't think I have any of that stuff. I've had that stuff for AMP2 classes, I think. But if you've ever taken a look at a coal miner's lung, it's actually really kind of scary because you look at it as this beautiful crystalline structure, and you're like, how the hell could that possibly be in somebody's lung tissue? And they breathe. Well, they couldn't breathe. They died from it. But that's exactly what you have. You have nucleation, the formation of crystalline structure that takes over the parenchyma of the lungs. So who gets occupational lung? Diseases, I mean obviously depends on what you're exposed to at work. The size of the particle, the shape of the particle, the amount of exposure that you have to it, any atmospheric pollutants that you've been exposed to before you got to work, and then the first bullet point pre-existing lung disease. No dude, I have no pre-existing lung disease. Really. Do you smoke? Parentheses. Anything? Close parentheses. Do you vape? Do you have a swamp cooler? Do you have a dog, a cat? Right, so all those things cause triggering of the inflammatory response, and that's kind of the point here. Okay, guys, so the next slide, pollutants interfere, paralyzes the ciliate, right. So mucociliary clearance doesn't happen. The thing goes all the way down to the alveoli, and it can't be removed. And then slide 42 tells you exactly what I just said. the macrophages try to engulf them and then they exit and they go into the bronchial walls, they go into the lung tissue, get stuck in the alveolar membrane, and all that stuff can cause inflammation and all that stuff can get thickened and have fibers deposited there and run away to pneumoconiosis. Same thing with slide 43, I've already explained that to you. Now here's the thing, slide 44. It's a damn problem, okay? People who have pneumoconiosis usually don't have any signs or symptoms unless they have some terrible predisposing factor like they're extensive smokers or whatever. They have no signs or symptoms until the disease is firmly entrenched and they can't do anything about it. So it's not unusual for somebody to be completely symptom-free for 10 or 20 years and then go in and have a little bit of dyspnea, that irritating, nonproductive cough, and maybe not any of that stuff. They do a routine chest x-ray, and it's like, oh, my God, you've got calcification of fiber all over your lung tissue, and then it's too late. And also, so one group of people who get these, if you go... by a road resurfacing crew, and those people work hard, okay? If you go by a road resurfacing crew and they're not, you see people who are not wearing masks, The bandanas aren't even really enough to filter out some of the fine dust from the surfaces that they're dealing with. But if they're not wearing masks, then they're inhaling particulate matter that has a crystalline structure that over time is going to bring about a pneumoconiosis and a restrictive lung disorder. It's just, you know, if you're too cool to wear a mask. So like a lot of people with COVID-19 have thought they're too cool to wear a mask or they're immune. Guys, no one's immune. Respiratory damage is respiratory damage. No one's immune from that. The problem is too, that the last bullet point, so somebody can literally be symptom-free 10 to 20 years even though it's been at work in their body that very same length of time. So what are the late features? Obviously respiratory failure, core pulmonology, talked about that. chronic hypoxemia, chronically low arterial O2 sats. So here's the other thing that's also damning. What do we see? The chest x-ray usually comes out clear. You don't know that anything's going on until there are symptoms. And then when there are symptoms, you have a positive x-ray finding. The problem with that is then that it's been entrenched in their body for a while. Then hypoxemia, hypercapnia. with pneumoconiosis, hypercapnia, they might even have some difficulty blowing off the CO2. So how do you talk to these people? Hey, if the only thing you know how to do is work on a road resurfacing crew, and it pays, and guys, it pays ridiculously great money, how do you tell somebody, hey, we just don't go back to that job, right? I mean, it's a problem, guys. We give steroids to downregulate the inflammatory response, dial down the immune system. We give bronchodilators to create more lumen diameter in the respiratory tree and an O2 therapy if necessary. But remember, by the time we've discovered it, it's usually too late. Prevention is the key, but how you tell somebody to quit their job if it's the only thing that they know how to do and it's, you know, paying everybody's bills. So, atelectatic. disorders, slide 49. Analyptasis is just a word that we use for the collapse of part or all of a lung. In ARDS, acute or adult respiratory distress syndrome, happens quite a bit. Sepsis is a big cause of it, and the mortality rate hovers about 50%, you know, anywhere from 40 to 60%. Not every hospital has the same success rate or failure rate. And the news has had lots and lots and lots of information about hospitals in the state about that. So I'll let you guys look that up. So how do you get to ARDS, severe trauma, certainly. Sepsis is a big cause of it. My own father died because of aspiration of gastric acid, a fat emboli, and shock. We've talked about shock. I don't care about a fat embolus. So my father had GERD, gastroesophageal reflux disorder, which we'll talk about in the next unit. And he was also an insulin-dependent diabetic. And because he was a diabetic, he had lots and lots and lots of problems with his health. And I can tell you that the data all shows Who's the person most likely to be sick of all people in all age categories, all things being considered? A person with type 2 diabetes. We'll talk about diabetes towards the end of this semester. It's the gold medal that you hang around your neck for not having taken care of your body. And I don't mean that to be offensive, but it's shocking. Yeah, well, good. So start eating right and exercising so you don't get it. And he was in the hospital. He had been sick, and his recovery was protracted because people who have diabetes, their high sugar levels dialed down the immune system response. So it took him, I think he had been in the hospital for three weeks with what was effectively really just a mild flu situation. And a handful of days before, he was scheduled to be discharged. He's feeling better because he was a diabetic. He was also doing some not all the time when your kidneys go. because when diabetes is fully entrenched in a person's body, and we'll talk about it, renal function goes to hell, ultimately. And one of the things that the kidneys do is they purify, they get rid of, they filter out toxins, but they also produce hormones that have the right, that cause EPO to be healthy. kidneys EPO is released and causes the red bone marrow to make red blood cells etc. So my dad's kidneys were hermed and he was supposed to do some dialysis. He wasn't doing it on a regular basis it was just to help every once in a while boost his kidney function and he was going to be brought down after lunch to the dialysis unit in this particular hospital carried about literally about two or three days before he's supposed to be discharged. He asked the nurse in his quiet schmooze, I'm a kind old grandpa kind of guy way, hey, the food that they gave me wasn't enough. Can you please give me some more food? And so she gave him, I think, another full tray of food. And it was diet restricted, but he ate another full tray of food. He gets wheeled down to his. dialysis he's waiting in line to go into the dialysis unit in the hospital there's nobody else in the hallway he's on the gurney and he asked to be lowered so he could you know maybe take a nap so the nurse complies with all of these requests and he aspirated gastric acid it went down and 24 hours later I was on the phone from here in New Mexico Telling the physician, yeah, that's it. I don't want any more efforts. I just let my dad go. And all of that was because of a health care provider doing what she felt emotionally was the right thing, but ignoring what was good standard protocol and what was written in the chart. So ARDS happens mostly because of sepsis and aspiration of gastric acid. So pathogenesis. It is a pulmonary edema that's caused because of the, you got it, inflammatory response. Notice though, on slide 52, it says it's non-cardiogenic. Right. The pulmonary edema that's caused doesn't happen because of heart problems. It happens because of the destruction of tissue that happens in the lungs itself. So when somebody is in pulmonary inflammation. when there is the inflammatory response going on in pulmonary tissue. What happens is there's edema, so fluid leaks. We get surfactant dips. If there's fluid, it dilutes the surfactant that's in the alveoli. What happens with that is then we have atelectasis that happens, those parts of the air sacs that don't have sufficient surfactant collapse. And then the inflammatory process continues doing what it's doing, and it deposits proteins to reinforce the tissue to structure. And that's why we call it a hyaline membrane disease. We get fibrosis, and that's it. It's restrictive lung disorders. In the alveoli are injured, the alveolar walls are injured, the capillary beds are injured, and the interstitial tissue is injured. And all of that disrupts the ability to deliver oxygen to the right places. And eventually what happens is we deposit these proteinaceous fluids and they go into the alveoli, which of course impairs ventilation. So bringing it full circle, page 56, what happens is we've got deposition of protein. in the lung tissue, the alveoli are collapsing, and you do a film study, and what do you see? Fluffy, diffuse alveolar infiltrates. That's just another way, a nice way of saying you see white out. It's like it's snowed. And what is that? That's the deposition of fluids in the alveoli, in the pulmonary interstitium, and you've got fibrosis that's going on. So who's the person most likely to see somebody crash or to potentially catch the early signs before the person crashes? Because early intervention. before ARDS fully sets in is a game changer. That's the key. So what happens is the person might become slightly agitated. You've got somebody who's on a monitor in the ICU and you're watching them, and all of a sudden their O2 level drops just a little bit or they start breathing more rapidly or they become agitated. disoriented or irritable and that's just not their personality. Uh-oh, that might actually be the person slipping away into ARDS. Then of course tachycardia, tachypnea, you know using all kinds of accessory muscles to do whatever you can. And so on slide 59 there is one of the most important things that can be said. about ARDS and about pulmonary disorders in general. The hallmark of ARDS is hypoxemia, not enough O2 in the vasculature, refractory 2, means not responsive to, increased levels of supplemental O2. So what does that mean? You put on the nasal cannula or the oxygen mask and it doesn't do crap. That's what it means. Jim, you mean like in sepsis? Yes. Remember we said one of the dangers in sepsis, going into shock, septic shock, one of the dangers was the person hits ARDS. And if they hit ARDS, they have a hypoxemia. Now we have the phrase, a hypoxemia that's refractory to supplemental O2, no matter how much O2 you give them. And we already... talked about the mechanism of that and why that's a big deal because the tissue simply can't use the O2 and why is that because the tissues are literally being destroyed by the inflammatory response so that there isn't a concentration gradient or meaningful tissue to need the oxygen. Slide 61 whiteout I already mentioned that to you guys Cellular debris, I mean, there's edema everywhere in the interstitium, in the alveoli. There's the hallmark findings of the inflammatory process and the wreckage that it leaves behind, and then lung collapse, atelectasis. So the treatment for this, mostly supportive. You do all that you can. You give oxygenation if you can that's tissue-specific. I'll let you guys figure out at work. someday what that is. It's beyond the scope of this class, but we can do some tissue oxygenation, tissue-specific oxygenation, but it's not systemic, and that's a problem. And then we do what we can to dial down the inflammatory response and figure out what the cause is and try to remove whatever the cause is. So it's not unusual to give somebody some Jetted air, so slide 64, that you intubate them and you do positive end-expiratory pressure. And that's a good thing to try and keep somebody alive, okay? But I think we've learned from all of the intubations that were done to severely hypoxic COVID-19 patients that it was actually, all the data seems to indicate, that intubation as necessary as it was actually hastened the destruction of those people's lung tissue. And how could it do it? So in the best of all possible worlds, assuming no COVID-19 infection, when we do positive end expiratory pressure, what we're doing is there's a jetted in air, inspired air, and that causes the... proliferation, inadvertently, not much we can do about it, of oxide radicals which destroy the membranes that they're coming up in contact with. Like what? Oh yeah, like the alveoli, okay? So long term, even though this could force fluid out short run and potentially get oxygenation in somebody's body who's able to get their oxygen, it nevertheless destroys the actual membranes of the tissues. In high-frequency jet ventilation, that's part of it. So there's that picture, slide 66. And there's a lot that's going on there. The only thing you guys need to know, it's easier to talk about it in person, but it was just frosting on the cake. They have actually a nodule, so they probably had some other things going on as well. And that's that big dark circle in the left picture, which is on the right lung. But what do you see? Basically snow everywhere, and that's whiteout. So IRDS, infant respiratory disease. distress syndrome is the infant analog of ARDS. So ARDS, acute or adult respiratory distress syndrome, IRDS is infant respiratory distress syndrome. It's also high on the membrane disease and it works exactly the same way with everything we just got through saying about ARDS. The big issue is that it's almost Exclusively related to a dearth of surfactant in a child that's born very early prematurely so 60% of the infants born Younger than 30 weeks when they're not treated with corticosteroids Can die from IRDS In you know using some corticosteroids quite literally dramatically cuts in half the sequela and the problems. And still at 34 weeks, just before 34 weeks, 5% of the infants do show IRDS. So one of the risk factors, premature birth. That's the big one. The other thing that's kind of counterintuitive, but it's just that it has profound biochemical explanations that make sense. So if a mom is at 43 weeks, God forbid, when she delivers, so advanced gestational age, then you may see IRDS as well. And then in a mom who does not control her diabetes, that's very, very, very high incidence of IRDS. So other high-risk factors, slide 69. C-sections without antecedent labor. So when I was training to be a doctor in the 90s, if a female wanted to get a C-section at a certain time because, well, hey, in three weeks I'm supposed to go on a ski trip to Vail, Colorado, we used to go ahead and do those procedures. Why not, right? There's money to be made, and who cares? There is no data about the neonates. Well, now we know that in those situations where there wasn't at least labor started before the C-section, there's a higher incidence of IRDS in those kids than any other group of newborns. All other things being adjusted as being the same. So now, if you have a scheduled C-section, or if it's an emergency but not like the child is going to come out right this moment, We like to do a Pitocin drip and encourage a little bit of active labor, which causes the catecholamine explosion in the neonate that seems to help preempt IRDS. Perinatal asphyxia, obviously, if the cord is wrapped around the child, or if it's a second twin, and it's the second child, and there's a delay in that child coming out after the first one has come out, because then the placenta isn't... servicing the second twin that great before the second twin comes out. Also, if a mom has had a prior pregnancy where there has been IRDS, for some reason there is a higher statistical occurrence. Now, that has all sorts of potential ramifications, but the literature is all over the map on what exactly that means. And then, obviously, RH factor incompatibility, that's a no-brainer. The issue, though, is when the child is born without the surfactant or without enough surfactant, it's not the... So you have to replace the surfactant immediately, and you have to administer surfactant immediately. And how do we do that? Synthetic or bovine from cows or porcine from pigs. The other issues, though, are... Are the tissues involved sufficiently thinned, and are the capillary beds sufficiently matured, developed, and proliferated so that once we overcome the surfactant issue, are those... other two issues, thickness of the membranes, maturity and development of the capillary beds that feed the membranes. Are those the reasons why there's an issue now? So what happens is a neonate newborn is born. If a neonate is born with IRDS, they may look cyanotic, they may look blue, and they might be breathing. But what happens is with every exhalation, if they have a lack of surfactant, then the... alveoli collapse at least in certain regions and then they have to struggle to create enough pressure to pop them back open again but the next cycle becomes progressively more difficult which wants even greater pressure generation to pop it back open and so this is a restrictive lung disorder because there's lung collapse and it's very difficult to try and pop open the lungs and why do they collapse no surfactant or inadequate surfactant. And then what happens is if we let it go, then atelectasis progresses to the other parts of the lung and there's profound vascular resistance in the pulmonary vasculature which causes great stress on that newborn heart. So skipping to slide 74, we have the inflammatory process. Okay so hey there isn't any in the any surfactant or there isn't enough surfactant so the lungs are the alveoli are collapsing upon themselves and at least initially maybe the child's able to pop open those alveoli again struggle um to do that and there's injury and the inflammatory response gets triggered and we're off to the races again so protein deposition etc um what do we do we can administer so you administer um a surfactant and then you give forced inspiratory O2, JETAT-O2, you want to do that for as little as possible, but as long as necessary. And that's a fine balance because that JETAT-O2 creates oxide radicals that can actually destroy the lung tissue and potentially beget lifelong respiratory challenges for that kid. Early on, how do you know that a kid has armor? IRDS, well, they're using their little ribcages moving in all kinds of strange ways. Their nostrils are flaring, and they have very shallow respirations. The other thing is that the blood pressure drops. There's hypotension and bradycardia, and I know that that seems counterintuitive, but when there's IRDS and it's spreading through, the blood pressure, So the child is basically going into shock and bradycardia because there isn't enough O2 for the heart. There's edema and obviously the child's body temperature is low. Why? Well, because the heart's not doing a good job pumping the blood everywhere and there's not enough oxygen. And so it's the blood that warms the body and the heart is going to have a problem if there's no intervention. And in tachypnea, I've actually seen kids, how do you even clock, how do you even time as a medical professional 60 to 120 respirations a minute? But I've actually seen that. So the other thing is slide 76, the frothy sputum, that may or may not happen, but you hear grunting sounds with expiration. Why? That's the alveoli slamming shut on each other. And you see. awkward or seesaw or paradoxical respirations in the chest. And it's the same, you know, white-out or ground-glass appearance on x-ray with alveolar edema. Now, here's the thing that's very fascinating. And let's just pause here. I want you to think about this. So, you've heard of amniocentesis. So, that's reaching a... putting a needle in ultimately to sample the amniotic fluid and you're looking for a bunch of stuff. One of the things that you're looking at if a mom is going into contraction or if there are signals, all sorts of physiologic signals that we won't talk about, that it looks like the child might actually come out soon and far too soon. You do an amnio and you're looking for a few things. One of the things that you're looking for is What's the ratio of lecithin to sphingomyelin? And these, ultimately, what you're doing is you're looking for byproducts of biochemical pathways. And if there is enough surfactant... present. How is that going to show up? Well, we sample the amnio fluid and we see phosphatidylglycerol. If that's present, we're happy. If the lecithin to sphingomyelin ratio is at least two to one, then the likelihood of getting IRDS is less than five percent. Okay, and if we think that we're in the gray zone or we don't have a choice, fetus has to come out. And what we do is we boost mom IV and we give a massive dose of glucocorticoids right before delivery. And that actually helps to quicken the maturation of surfactant producing cells. And then on slide 79, again, prevention is the key. We want to administer surfactant. If we have to, that's the next slide. But just administering the surfactant doesn't necessarily guarantee that all is over. Often the child needs to be put on some sort of ventilatory support. Obviously the more premature the child is and with that being the case using mechanical ventilation PEEP or force inspiratory O2 that itself can bring about ultimately mechanical destruction in lifelong respiratory problems. Notice on the next slide, administering a misogynist surfactant quite literally decreases mortality by at least 50%. That's a major, major, major accomplishment. Supportive therapy on the next slide, why do we do neutral thermal environment so they don't get agitated? Why do we do minimal handling so they don't get agitated? Why do we care about agitation? Because agitation begets crying, which requires ATP. which requires O2. So we want to do as much as possible so that the child has as little of a metabolic demand as possible. Okay, so slide 82, pleural space disorders, pneumothorax. So we have the pleural sac that's around the lungs, each lung. Each lung has its own pleural sac. In the pleural cavity, that's in the pleural sac, there's fluid. How much fluid? Remember, we said just enough. So what's a pneumothorax? A pneumothorax is when air, for whatever complicated sets of reasons, we'll look at a few, gets into that space. And what can that do? Well, there goes the negative pressure, the pressure drop between the pleural space and basically the rest of the... pleural cavity, and if there's a tear and air comes in, what happens is it essentially forces the lung to collapse on that side. So there are secondary pneumothoraces, which is what we're going to look at. Something happens in one region, brings this about in the lung tissue. A primary pneumothorax, on the other hand, happens and arises spontaneously in the lung tissue. There was a young man several years ago, really tall, like 6'7", 6'8", and he was a smoker. Everything else totally fine. He's perfectly healthy otherwise. He's walking past UNMH and he collapsed and he had a primary pneumothorax. But if you're going to have one, where is it to have one right in front of the hospital that can take care of you? So he made it through. The bottom line is we don't really understand what the mechanism is, but it's guys mostly who are very tall and who smoke, but are otherwise very healthy. And that's it. So we're going to look at secondary pneumothoraces. In slide 83, notice there's a list, and there are many more diseases that can bring it about. So people who have asthma, oh my god, pause, just relax. emphysema, cystic fibrosis, infectious diseases like pneumonia, we're going to talk about that. NTB, we're going to talk about that. So what's the big deal here? The big deal here is that those diseases, whether they're obstructive or restrictive, can potentially cause us to have to accidentally at times jack up the pressure in the pulmonary tissue by doing what? Coughing to clear our mucus to clear the fluids in the alveoli, whatever the disease process happens to be. When we do that, there are structural abnormalities. Blebs, for example, I love that phrase. There are structural abnormalities. And we all probably have a few blebs on our tissues, thinnings and funky structurings of the pleural sac. And if that ruptures, while air comes rushing in. And why? Because remember, it's at four millimeters of mercury pressure lower than whatever the pressure is in the lungs and the surrounding atmosphere. So there are catamenial, next slide, catamenial pneumothoraces that can happen that are associated with menstruation, but almost exclusively in people who have fairly entrenched endometrial disease. So don't... you don't become neurotic about that. It happens, but if you don't have a history of endometriosis, then the likelihood of it being a factor is pretty non-existent. Then there's a tension pneumothorax, and obviously if there's a penetration wound, a knife or a bullet or whatever, that can certainly cause a tension pneumothorax, but it doesn't have to be non-penetrating. So, for example, people who in this, state believe they qualify for MMA or UFC fighting because they've won a fight or two when they were growing up and they wear some scary tattoo that, you know, to intimidate people. And, you know, you're practicing in the gym or you're practicing in the garage at home and somebody hits you in the chest pretty hard because, you know, you're grappling, you're trying to toughen yourself up or whatever nonsense is promulgated. You get hit hard enough that can cause a tension pneumothorax. Hey, you didn't wear a seatbelt and you hit the steering wheel when you got rear-ended or when the person in front of you came to a sudden stop or ran the red light. You hit somebody who ran a red light and you hit the steering wheel pretty hard. That also can cause a tension pneumothorax. So next slide, we've got these weird things called the blebs. obviously if there's a problem with the ribcage, with, you know, there's a structural problem, whatever, but the blood ruptures and air comes rushing in and then the lung collapses. Now listen, when the lung collapses, ipsilateral, slide 86, ipsilateral means same side. When a lung collapses on one side because of all of these things that we're talking about, that side bulges out because now it becomes, whatever the atmospheric pressure is, it gets filled with that air at the atmospheric pressure. And that exerts a pressure on the contralateral side. So if you do an x-ray of somebody who has had an atelectasis because of a pneumothorax, You see on the film study the deviated trachea and the great vessels, they get pushed over to the other side. So that's a contralateral tracheal or mediastinal shift. That's a really big deal because that impinges venous return and cardiac output and potentially. It impinges air going into the trachea as well, all the way down to the lungs. And super easy to pop a collapsed lung back into place. And there's many ways to do it, whatever. Let's look at slide 89. There are people who have small pneumothoraces, less than 20%, so not even a fifth of the volume. And they don't even know. that they have a pneumothorax. And those you generally don't want to treat because the body's going to be able to figure it out and do the repair. Anybody who's got any kind of substantial pneumothorax, though, is going to have tachycardia because there's decreased lung capacity and there's injury and there's pain. Of course, there's going to be decreased breath sounds and hyperresonance on the side where the lung collapsed because it got filled with air and the lung is collapsed. You can't... put any air in it and it's um sudden sharp shooting pain in the chest These are, so tension pneumothoraces and large spontaneous pneumothoraces are medical emergencies because obviously there's no air and because you have contralateral tracheal shift. So slide 91, this guy appears in a number of pictures in the book and in my PowerPoint slides, this poor schlub was very harmed and experienced many different respiratory ailments. And so he's very bloated, but he's bloated because he's got edema and pulmonary edema and alveolar infiltrates. So when somebody has a pneumothorax, what do you see? Obviously, they've lost lung compliance and they don't have an ability to bring air in. So there's decreased arterial load, too, and that's why it's a restrictive lung disease. The chest X-ray, you see a hemidiaphragm. decompressed hemidiaphragm. So on the side of the x-ray where the lung collapsed, it got filled up with air and it's atmospheric pressure wherever the atmosphere is and that pushed down or deflated or decompressed the diaphragm so that there is no diaphragmatic excursion even possible. And let's take a look at slide 93. It's counterintuitive But you say, hey, I see clear lung fields on the left in that picture. No, actually, you see no lung fields. That lung has collapsed. How do you know? Well, you can sort of see a dark silhouette that's oblong in there, and that's a collapsed lung. The other thing that you can see is you see a very profound contralateral tracheal shift along with the... main blood vessels that are in the superior mediastinum. For crying out loud, everything looks like it's completely over in the other pleural cavity. So that's a vintage indicator where the lung was that collapsed. So what do we do with the lung collapse? Well, if somebody has less than 15% of their lung that's collapsed, you don't really do anything. They may not even need to be hospitalized. It just all depends what kind of pain they're in and what caused the collapse. And if it's up to a quarter of the lung, you can put a chest tube in there, and that helps to radically reinflate, quickly reinflate the lung. You also want to go in and fix the blebs. And so we can go in and do chemical pleurotesis or... you know use a laser or whatever and what that does is we just do adhesions so the area where the tissue was very thin and structurally weak by frying it chemically or with a laser whatever you cause the development of instantaneous development of scar tissue and that by definition strengthens the tissue there so it won't happen again we can also go in and staple the tissue together Okay, so then on slide 97 is pleural effusion. So pleural effusion, we go back to what I've been saying, how much fluid is there in the pleural cavity? Just enough. So if we ask what's just enough, so in the nepharatis family, because we're all relatively compromised in height, it's probably 5 to 15 milliliters of fluid. In Shaquille O'Neal, it's probably 5 to 15 milliliters. 50 to maybe 65 milliliters of fluid because his lungs are so big and the whole point of having that fluid there is to prevent the two membranes the parietal and the visceral pleura from sticking against each other and irritating each other causing inflammation and infection and to allow them to be able to move seamlessly frictionless frictionlessly past each other without touching each other Now, the next few slides, transudates, exudates, epiemas, hemothoraces, I don't really care about that stuff. The point is there's all kinds of stuff that could be found in the pleural cavity, and the stuff that can be found in the pleural cavity either has osmotic or hydrostatic pressure that it exerts, and it can keep fluid in the cavity or draw fluid out from the surrounding tissue in. to the cavity so that there is a persistent elevation of fluid in the pleural cavity. I do actually want you to know what an MP-EMA is, not On slide 100, it's not empanada, but empiema. And that's the one, I guess, pleural effusion that I want you to know. It's brought about by a bacterial infection in bacteria, released pus, which is filled with protein, and that's an exudate, and that exerts an enormous osmotic pressure gradient to keep fluid in there. So what kinds of things? bring about pleural effusions. There's a bunch of things. The issue is what happens when somebody gets a pleural effusion. Well, slide 104, the question is begged. It's how much is noticeable before we think about it. So the general rule of thumb is that a person is usually asymptomatic if it's less than 300 milliliters of whatever the fluid is that goes in. So a pleural effusion that... exceeds 300 milliliters or a spontaneous rapid influx of fluid pleural effusion, those are the ones that are potentially medical emergencies and need to be addressed because it can collapse the lung. So what happens to the person? They get sharp pain that hurts like hell when they breathe in, hence it's a restrictive lung disorder, because if the pleura is filled with fluid, then that means the lungs cannot expand completely, and that's why it's a restrictive lung disorder. And there are few, if any, breath sounds. The more fluid that there is, why? Because sound doesn't travel through water or through fluid, and so fluid is surrounding the lungs and filling up the pleural sac. That's why there is... absence of breath sounds. Dullness to percussion, same reason. Decreased tactile fremitus, that's when you have your hands on the person's back and there's no vibrations when they speak. Why? Because again, it's the sound is not able to go through the fluid that's in the pleura that surrounds the lungs. And again, with a big enough pleural effusion, you can get the contralateral tracheal shift. Why would you want to do slide 107 of thoracentesis? Because you want to figure out what's in the fluid to determine what caused the problem in the first place. And obviously doing a CT scan is a gold standard here also, because that can help reveal what's going on and the details of what's going on. The big issue, so pleural effusion is big enough as a medical emergency. The big issue for controversy is... that we can do in adults. We can put a closed chest tube for drainage. Why is it controversial to do it in kids, pediatric patients? Because it's so much easier to accidentally puncture the heart. I've actually seen that happen. So yeah, it's a very, very, very serious thing. So slide 110, poliomyelitis, we're not going to cover, we're not interested in. Slide 112, Lou Gehrig's disease or amyotrophic lateral sclerosis. That's what killed Stephen Hawking. We're not going to cover that. And what we're going to do is, that's the end of this particular lecture. This is part one. Part two will be a much shorter lecture, and we'll finish up chapter 23, restrictive lung disorders.

They're antithetical to the obstructive lung disorders. With restrictive lung disorders, whatever air is inside, we can get out. We just have a difficult time getting the air in originally. So that's the conceptual difference between the two, and we're talking now about restrictive pulmonary disorders. And yeah, there's 181 PowerPoint slides, but we're not covering anywhere near all of those.

That's good news. Also good news, it's the same doggone inflammatory response that works that brings about the damage here, but we're going to talk about that. So generally speaking, how is it that there can be decreased lung expansion?

So either there's a change with the lung tissue itself, the lung parenchyma or interstitial tissue. There's a change with the pleura that surround the lungs. There's a problem with the chest wall itself, or there's a problem with the neuromuscular junction or neuromuscular function, and we'll actually talk about that specifically. So the capacities, the next slide, the capacities that we talked about in terms of the four lung capacities and four lung volumes, what they were for obstructive disorders, they are the exact opposite for restrictive lung disorders.

In restrictive lung disorders, we have decreased vital capacity where there is increased vital capacity. There is decreased lung capacity, there is increased in obstructive. FRC here and residual volume are lower compared to what they were in obstructive. lung disorders. So the other thing that's really interesting is the arterial blood gases.

So remember, with restrictive lung disorders that are exactly the opposite of obstructive lung disorders, we can't, whatever error we have, we can get rid of. And that accounts for, conceptually, why there are normal or even decreased levels of CO2 on the arterial side, because whenever we have to blow off, we're able to blow off. The issue is we can't expand to get air in. And so what does that mean? That's where we get the decreased arterial O2 levels.

So on the next roughly 10, 12 slides, I am, you're not responsible for fibrotic interstitial lung disease. nor diffuse interstitial lung disease. What I'm going to do is I'm going to use these two as an explanation for what happens in all restrictive lung disorders, regardless of whatever the etiologic agent may ultimately be.

So whatever it is that happens, there is damage to the alveoli, the epithelial cells, the single... simple squamous epithelial cells, they're lying the alveoli, or there's damage to the capillary beds that are served by the alveoli. When there's damage, the walls get thickened, ultimately, in the interstitium and the alveolar walls. And what happens is with repetitive damage, as there is repetitive damage, we have repetitive inflammatory response. And when we have constant inflammatory response and damage, ultimately we do what?

We deposit collagen to try and buttress the tissue that was harmed. So inflammatory response gets started for reasons that we're going to talk about. It brings about damage to the alveoli, to the alveolar walls, and to the capillary beds underneath. And ultimately...

that causes those to become thicker and we deposit protein structure, collagen, to reinforce those as well as the interstitial lung tissue, which is where the alveoli are ultimately parked in. In that process, what we've done is we're depositing fibers in tissues that are supposed to expand or move and are not supposed to be weighted down with extra fibers. So what is restrictive lung disorder? we've lost the capacity to expand our lungs.

Why? Because regardless of the particular process that's at work, that started the whole thing, the inflammatory process causes damage to the alveolar walls, to the capillary beds underneath, and or to the interstitium that's behind, or that the alveolar walls are a part of. And there's enough damage and enough inflammatory process activity going on that ultimately collagen reinforcement gets deposited. And when collagen reinforcement gets deposited, we lost the expandability of the lung tissue.

We reduced the lungs'compliance. So the lungs can't ever fully open, and they can't ever bring the right amount of air in. But that's why whatever's in can go out. So briefly, let's turn to slide 11, and I'm out.

What happens? Well, there's progressive dyspnea with exercise, and these people desat. It doesn't matter which particular restrictive lung disorder that we're talking about.

You get somebody in a pulse ox, and you have them exercise. If they have an established, well-entrenched restrictive lung disorder, when they exercise, they're never going to benefit from exercise. When they exercise, because they can't bring in enough oxygen, O2, their lung expansion capacity is permanently compromised because that's the case. Instead, they use up their O2 stores, they just desat. And that's obviously disastrously bad.

Often, people who have restrictive lung disorders have a non-productive cough and it's irritating because they can't ever clear the mucus that's deep within out. And why is that? If you can't bring enough air in and the lungs are not sufficiently compliant because now there's fibrosis at work in the lung tissue, then you can't generate enough pressure, the 100 millimeters of mercury pressure, to be able to clear what's inside. These people tend to have end-expiratory crackles or RALs. It's literally like taking two pieces of Velcro that are attached to each other and prying them apart from each other, that's what you can hear in advanced restrictive pulmonary disorders.

And why do they have anorexia and weight loss, slide 12? Because they spend so much ATP on the work of breathing, trying to get every extra cubic centimeter of air to come into the lungs. With restrictive lung disorders, the... Chronic ones, some are acute like pneumonia, but in the chronic ones, exercise does not allow the person to be able to increase cardiac output.

As a matter of fact, exercise is actually very bad for them. So let's go to slide 15, treatment, get people to stop smoking. Why?

Because that's an inflammatory process triggering event. Every single inhalation of any substance triggers the inflammatory process, the one thing we don't want happening. If they got the restrictive lung disorder because of exposure to certain environmental irritating factors, we want to remove that from them.

We give anti-inflammatory agents. Why? Because we want to dial down the inflammatory response.

which is the reason why we do immunosuppressive agents, because when we're talking about the inflammatory response, we're really talking about an immune system response that is actually so harmful it's causing lung damage. Do these people qualify for lung transplants? I don't want to say anything at all about transplants, period, so I'm not going to respond to that. Okay, so sarcoidosis, slide 16, happy times. I'm not covering sarcoidosis.

I know that there's a prevalence of sarcoidosis in this state, but I don't want you guys to waste any time learning about it. So slide 26, hypersensitivity. Pneumonitis.

Pause. Pneumonitis, inflammation. Hypersensitivity is just from patho1 the way the disease process or the mechanism of injury is affected. So another way to refer to hypersensitivity pneumonitis is extrinsic allergic alveolitis.

So what is this? The alveoli get inflamed because of something that they're very sensitive to. That's what it is.

It's primarily found in people who've never smoked, and it can be an occupational disease as well. So let's just briefly look at slide 27, farmer's lung. So until relatively recently, where the cabs of tractors that farmers sit in as they go over cornfields, soybean fields, whatever it is, they used to be open, and farmers inhaled a lot of particulate matter, and that's how.

farmer's lung came about. Bird fancier's lung. So I'm not trying to rain on anybody's parade. I'm going to say this though, anybody who has a pet bird or chickens, if you are remotely possibly inhaling anything that comes off of them, no, no, Jim, we have, you know, we lay down protective stuff around the cage in the house, et cetera.

Yeah. Guys, if it's in the house, that means it's aerosolized. You are at risk. So pet birds and chickens all can cause bird fanciers'lung, which brings about the restrictive pulmonary disorders I began this lecture with.

People who love to go hunt for mushroom and get mushroom are people who make cheese. Cheese makers'lungs, shout out to the Aaron Rodgers fans in the world. I'm no fan of Aaron Rodgers. I'm from Chicago, after all. But cheesemakers, same thing, particulate matter.

Grain handlers, lungs, same thing. Pituitary extract hypersensitivity. Yeah, so a lot of people are taking a whole lot of health food concoctions and energy formulas and special concoctions, sometimes with pituitary extract in them to get their muscles to be bigger. That's all I'm saying. Fish, meat, workers, lung.

When we had an NFL season and games happened in Seattle, they would always show before the game or during commercials, on the way back from a commercial, back to the game, when the Seahawks were playing, they'd show fishmongers at fish markets throwing fish to each other for the sake of the camera and to chop the fish head and tail off and to package it up for the customer. Those are fishmongers. Yeah, they inhale all kinds of things that can...

destroy their lungs. And then humidifier lung, pause. Thermophilic bacteria, amoeba and fungi. Notice what causes it.

Humidifiers, hot air humidifiers, so things that make the water hot, and then evaporative coolers, also known as swamp coolers. But Jim, my response, next slide. So I want to say there are a couple things about hypersensitivity, pneumonitis, that sometimes confuse students.

So the first thing that I want to say is that we have antigen antibody complexes. So they get formed, they get wedged in the tissue, that antigen antibody complex causes destruction to the tissue, which triggers an inflammatory system response. That's how that happens.

Okay. Now notice it says on this slide type 3 hypersensitivity reaction. That's a B-cell hypersensitivity reaction.

But then we can also have on slide 29, it says a type 4 reaction. Right. So hypersensitivity pneumonitis can be triggered as a type 3 B-cell mediated hypersensitivity reaction or a type 4, which is a T-cell mediated hypersensitivity reaction. In the type 3, antigen antibody complexes get stuck in the alveolar walls, and then we have the inflammatory process. In type 4, we have granulomatous inflammations that happen.

So the symptoms on slide 30 for acute hypersensitivity pneumonitis as opposed to chronic. For acute, the symptoms start relatively shortly after exposure. four to six hours and they resolve and about a day later And what are the symptoms?

So myalgias, pain, weakness, sweating, chills, like they're sick, headache, malaise, lethargic because of lack of oxygen. And when you talk to one of these people, you get a patient and they come and they say, you know, it's really weird because all week long I have these symptoms. But for crying out loud, by Saturday night, Sunday morning, I'm actually feeling a whole lot better.

You ask, do you work over the weekend? No, I don't. What do you do for?

a job and they tell you, boom, you just discovered the reason why they have hypersensitivity pneumonitis. So respiratory symptoms, there's a dry cough perhaps, but they're breathing rapidly. Why?

If you can't expand the lungs, you still have to do four liters of alveolar ventilation a minute if you're going to get the right oxygen amount. So what does that mean? If you can't take a bunch in with each cycle, well, you got to have more cycles. So that's where the tachypnea comes in from. Chest discomfort because there's not enough O2 in the inflammatory processes at work.

And then dyspnea at rest, so they can't breathe well. Well, obviously, because the lungs can't expand. Intermediate, so as this is developing, there is a cough that sets in that remains as the fibrosis sets in, as the deposition of collagen fibers.

begin to set in. And then there's persistent dyspnea and fatigue. Eventually, the fibrosis in the pulmonary interstitium causes a dramatic increase in the resistance in the vascular supply, pulmonary vascular supply, and that, of course, works itself out and abuses the right ventricle so that core pulmonoly ultimately happens. In chronic hypersensitivity pneumonitis, You do an x-ray and what do you see? Even the upper lobes are completely filled with fibers, with scar tissue basically.

And that's it. That's disastrously bad. There's no turning around from that. So skipping to slide 34, what's the whole point of skin testing? Well, if you suspect hypersensitivity and pneumonitis, you need to be able to tell them what to avoid.

And you have to figure out what that is. That's why you do skin testing. You might see increased, depends on when, after they have symptoms, if they've been around recently, the thing that's triggering it or not. But if they're around the antigen at the time that you actually do the blood draw, then you're going to see elevated WBCs, not necessarily neutrophilia, but elevated WBCs, and you're going to see potentially drop as it's working itself out a drop in O2 sats and the pulmonary function test PFTs are all going to be the same that they're going to be in every restrictive lung disorder so you identify the agent and hopefully you remove it and why do you give oral corticosteroids because that dials down the inflammatory response so the next category slide 36 occupational lung diseases. So there's a lot that's here to summarize in a succinct, hopefully succinct fashion.

So how do people get occupational lung disorders? Well it all is up to whatever the gas or gases and or particle or particles are that they're inhaling while they're at work. And the bottom line is that atmospheric pollutants have a really huge effect on people's lungs.

So that can cause lung damage to begin, and then they go to an occupation where they have some particular gas or particle that they're dealing with that exacerbates a lung disease that's been triggered by atmospheric pollutants. So I don't care about any of this stuff on slide 37. I just want to point out cigarette smoke is on there along with photochemical accidents for those who like to develop their own films. And we're going to, slide 38, we're going to give a term of art, a general medical name to all occupational lung diseases, no matter what kind they are.

And we're going to call them, the name of that first bullet point, pneumoconiosis. And, pneumoconiosis, plural, those are just occupational lung diseases, and they are caused by inhaling, and it's important, it could be a gas, but often it's an inorganic dust particle. Why is it important that's inorganic? Because if it's inorganic, that means our body simply can't process it. And when it gets in, it causes damage.

And obviously, the greater the exposure, the longer the exposure, the worse the consequences are. You do not have to know anything at all about anthracosis, silicosis, or asbestosis. I've already named those a few times. You don't need to know them. What I'm going to tell you is that they all have very characteristic...

crystals with particular geometries. And here's what happens, and here's what happens in general to restrictive lung disorders when our alveolar macrophages take in something that they can't handle. So we get some crystal, and there's stuff you do have to know.

You get some crystal that goes in the macrophage, the alveolar macrophage, it attempts to process it, it can't. So it jettisons out. that crystal structure where does it jettison it to the pulmonary parenchyma or interstitium the main lung tissue when it gets there there is an inflammatory response that's triggered and we also that's bad and then we also have the deposition of a crystalline structure um that gets stuck into the parenchyma that's never going to leave and so what do we have we have collagenous fibers and then these crystalline structures being deposited in the lung parenchyma that's making the lungs fibrotic, they lose their compliance, their elasticity, can't expand, can't get air in. If you've ever seen pictures of coal miners'lung, and I don't know if I, I don't think I have any of that stuff. I've had that stuff for AMP2 classes, I think.

But if you've ever taken a look at a coal miner's lung, it's actually really kind of scary because you look at it as this beautiful crystalline structure, and you're like, how the hell could that possibly be in somebody's lung tissue? And they breathe. Well, they couldn't breathe. They died from it. But that's exactly what you have.

You have nucleation, the formation of crystalline structure that takes over the parenchyma of the lungs. So who gets occupational lung? Diseases, I mean obviously depends on what you're exposed to at work.

The size of the particle, the shape of the particle, the amount of exposure that you have to it, any atmospheric pollutants that you've been exposed to before you got to work, and then the first bullet point pre-existing lung disease. No dude, I have no pre-existing lung disease. Really. Do you smoke?

Parentheses. Anything? Close parentheses.

Do you vape? Do you have a swamp cooler? Do you have a dog, a cat?

Right, so all those things cause triggering of the inflammatory response, and that's kind of the point here. Okay, guys, so the next slide, pollutants interfere, paralyzes the ciliate, right. So mucociliary clearance doesn't happen. The thing goes all the way down to the alveoli, and it can't be removed. And then slide 42 tells you exactly what I just said.

the macrophages try to engulf them and then they exit and they go into the bronchial walls, they go into the lung tissue, get stuck in the alveolar membrane, and all that stuff can cause inflammation and all that stuff can get thickened and have fibers deposited there and run away to pneumoconiosis. Same thing with slide 43, I've already explained that to you. Now here's the thing, slide 44. It's a damn problem, okay?

People who have pneumoconiosis usually don't have any signs or symptoms unless they have some terrible predisposing factor like they're extensive smokers or whatever. They have no signs or symptoms until the disease is firmly entrenched and they can't do anything about it. So it's not unusual for somebody to be completely symptom-free for 10 or 20 years and then go in and have a little bit of dyspnea, that irritating, nonproductive cough, and maybe not any of that stuff. They do a routine chest x-ray, and it's like, oh, my God, you've got calcification of fiber all over your lung tissue, and then it's too late. And also, so one group of people who get these, if you go...

by a road resurfacing crew, and those people work hard, okay? If you go by a road resurfacing crew and they're not, you see people who are not wearing masks, The bandanas aren't even really enough to filter out some of the fine dust from the surfaces that they're dealing with. But if they're not wearing masks, then they're inhaling particulate matter that has a crystalline structure that over time is going to bring about a pneumoconiosis and a restrictive lung disorder.

It's just, you know, if you're too cool to wear a mask. So like a lot of people with COVID-19 have thought they're too cool to wear a mask or they're immune. Guys, no one's immune. Respiratory damage is respiratory damage.

No one's immune from that. The problem is too, that the last bullet point, so somebody can literally be symptom-free 10 to 20 years even though it's been at work in their body that very same length of time. So what are the late features? Obviously respiratory failure, core pulmonology, talked about that.

chronic hypoxemia, chronically low arterial O2 sats. So here's the other thing that's also damning. What do we see? The chest x-ray usually comes out clear.

You don't know that anything's going on until there are symptoms. And then when there are symptoms, you have a positive x-ray finding. The problem with that is then that it's been entrenched in their body for a while.

Then hypoxemia, hypercapnia. with pneumoconiosis, hypercapnia, they might even have some difficulty blowing off the CO2. So how do you talk to these people? Hey, if the only thing you know how to do is work on a road resurfacing crew, and it pays, and guys, it pays ridiculously great money, how do you tell somebody, hey, we just don't go back to that job, right?

I mean, it's a problem, guys. We give steroids to downregulate the inflammatory response, dial down the immune system. We give bronchodilators to create more lumen diameter in the respiratory tree and an O2 therapy if necessary. But remember, by the time we've discovered it, it's usually too late.

Prevention is the key, but how you tell somebody to quit their job if it's the only thing that they know how to do and it's, you know, paying everybody's bills. So, atelectatic. disorders, slide 49. Analyptasis is just a word that we use for the collapse of part or all of a lung. In ARDS, acute or adult respiratory distress syndrome, happens quite a bit. Sepsis is a big cause of it, and the mortality rate hovers about 50%, you know, anywhere from 40 to 60%.

Not every hospital has the same success rate or failure rate. And the news has had lots and lots and lots of information about hospitals in the state about that. So I'll let you guys look that up.

So how do you get to ARDS, severe trauma, certainly. Sepsis is a big cause of it. My own father died because of aspiration of gastric acid, a fat emboli, and shock.

We've talked about shock. I don't care about a fat embolus. So my father had GERD, gastroesophageal reflux disorder, which we'll talk about in the next unit.

And he was also an insulin-dependent diabetic. And because he was a diabetic, he had lots and lots and lots of problems with his health. And I can tell you that the data all shows Who's the person most likely to be sick of all people in all age categories, all things being considered? A person with type 2 diabetes.

We'll talk about diabetes towards the end of this semester. It's the gold medal that you hang around your neck for not having taken care of your body. And I don't mean that to be offensive, but it's shocking.

Yeah, well, good. So start eating right and exercising so you don't get it. And he was in the hospital. He had been sick, and his recovery was protracted because people who have diabetes, their high sugar levels dialed down the immune system response.

So it took him, I think he had been in the hospital for three weeks with what was effectively really just a mild flu situation. And a handful of days before, he was scheduled to be discharged. He's feeling better because he was a diabetic. He was also doing some not all the time when your kidneys go.

because when diabetes is fully entrenched in a person's body, and we'll talk about it, renal function goes to hell, ultimately. And one of the things that the kidneys do is they purify, they get rid of, they filter out toxins, but they also produce hormones that have the right, that cause EPO to be healthy. kidneys EPO is released and causes the red bone marrow to make red blood cells etc. So my dad's kidneys were hermed and he was supposed to do some dialysis. He wasn't doing it on a regular basis it was just to help every once in a while boost his kidney function and he was going to be brought down after lunch to the dialysis unit in this particular hospital carried about literally about two or three days before he's supposed to be discharged.

He asked the nurse in his quiet schmooze, I'm a kind old grandpa kind of guy way, hey, the food that they gave me wasn't enough. Can you please give me some more food? And so she gave him, I think, another full tray of food.

And it was diet restricted, but he ate another full tray of food. He gets wheeled down to his. dialysis he's waiting in line to go into the dialysis unit in the hospital there's nobody else in the hallway he's on the gurney and he asked to be lowered so he could you know maybe take a nap so the nurse complies with all of these requests and he aspirated gastric acid it went down and 24 hours later I was on the phone from here in New Mexico Telling the physician, yeah, that's it. I don't want any more efforts.

I just let my dad go. And all of that was because of a health care provider doing what she felt emotionally was the right thing, but ignoring what was good standard protocol and what was written in the chart. So ARDS happens mostly because of sepsis and aspiration of gastric acid. So pathogenesis. It is a pulmonary edema that's caused because of the, you got it, inflammatory response.

Notice though, on slide 52, it says it's non-cardiogenic. Right. The pulmonary edema that's caused doesn't happen because of heart problems.

It happens because of the destruction of tissue that happens in the lungs itself. So when somebody is in pulmonary inflammation. when there is the inflammatory response going on in pulmonary tissue.

What happens is there's edema, so fluid leaks. We get surfactant dips. If there's fluid, it dilutes the surfactant that's in the alveoli.

What happens with that is then we have atelectasis that happens, those parts of the air sacs that don't have sufficient surfactant collapse. And then the inflammatory process continues doing what it's doing, and it deposits proteins to reinforce the tissue to structure. And that's why we call it a hyaline membrane disease. We get fibrosis, and that's it.

It's restrictive lung disorders. In the alveoli are injured, the alveolar walls are injured, the capillary beds are injured, and the interstitial tissue is injured. And all of that disrupts the ability to deliver oxygen to the right places.

And eventually what happens is we deposit these proteinaceous fluids and they go into the alveoli, which of course impairs ventilation. So bringing it full circle, page 56, what happens is we've got deposition of protein. in the lung tissue, the alveoli are collapsing, and you do a film study, and what do you see? Fluffy, diffuse alveolar infiltrates. That's just another way, a nice way of saying you see white out.

It's like it's snowed. And what is that? That's the deposition of fluids in the alveoli, in the pulmonary interstitium, and you've got fibrosis that's going on. So who's the person most likely to see somebody crash or to potentially catch the early signs before the person crashes?

Because early intervention. before ARDS fully sets in is a game changer. That's the key.

So what happens is the person might become slightly agitated. You've got somebody who's on a monitor in the ICU and you're watching them, and all of a sudden their O2 level drops just a little bit or they start breathing more rapidly or they become agitated. disoriented or irritable and that's just not their personality. Uh-oh, that might actually be the person slipping away into ARDS. Then of course tachycardia, tachypnea, you know using all kinds of accessory muscles to do whatever you can.

And so on slide 59 there is one of the most important things that can be said. about ARDS and about pulmonary disorders in general. The hallmark of ARDS is hypoxemia, not enough O2 in the vasculature, refractory 2, means not responsive to, increased levels of supplemental O2.

So what does that mean? You put on the nasal cannula or the oxygen mask and it doesn't do crap. That's what it means. Jim, you mean like in sepsis?

Yes. Remember we said one of the dangers in sepsis, going into shock, septic shock, one of the dangers was the person hits ARDS. And if they hit ARDS, they have a hypoxemia.

Now we have the phrase, a hypoxemia that's refractory to supplemental O2, no matter how much O2 you give them. And we already... talked about the mechanism of that and why that's a big deal because the tissue simply can't use the O2 and why is that because the tissues are literally being destroyed by the inflammatory response so that there isn't a concentration gradient or meaningful tissue to need the oxygen. Slide 61 whiteout I already mentioned that to you guys Cellular debris, I mean, there's edema everywhere in the interstitium, in the alveoli. There's the hallmark findings of the inflammatory process and the wreckage that it leaves behind, and then lung collapse, atelectasis.

So the treatment for this, mostly supportive. You do all that you can. You give oxygenation if you can that's tissue-specific.

I'll let you guys figure out at work. someday what that is. It's beyond the scope of this class, but we can do some tissue oxygenation, tissue-specific oxygenation, but it's not systemic, and that's a problem.

And then we do what we can to dial down the inflammatory response and figure out what the cause is and try to remove whatever the cause is. So it's not unusual to give somebody some Jetted air, so slide 64, that you intubate them and you do positive end-expiratory pressure. And that's a good thing to try and keep somebody alive, okay? But I think we've learned from all of the intubations that were done to severely hypoxic COVID-19 patients that it was actually, all the data seems to indicate, that intubation as necessary as it was actually hastened the destruction of those people's lung tissue. And how could it do it?

So in the best of all possible worlds, assuming no COVID-19 infection, when we do positive end expiratory pressure, what we're doing is there's a jetted in air, inspired air, and that causes the... proliferation, inadvertently, not much we can do about it, of oxide radicals which destroy the membranes that they're coming up in contact with. Like what? Oh yeah, like the alveoli, okay? So long term, even though this could force fluid out short run and potentially get oxygenation in somebody's body who's able to get their oxygen, it nevertheless destroys the actual membranes of the tissues.

In high-frequency jet ventilation, that's part of it. So there's that picture, slide 66. And there's a lot that's going on there. The only thing you guys need to know, it's easier to talk about it in person, but it was just frosting on the cake. They have actually a nodule, so they probably had some other things going on as well. And that's that big dark circle in the left picture, which is on the right lung.

But what do you see? Basically snow everywhere, and that's whiteout. So IRDS, infant respiratory disease. distress syndrome is the infant analog of ARDS. So ARDS, acute or adult respiratory distress syndrome, IRDS is infant respiratory distress syndrome.

It's also high on the membrane disease and it works exactly the same way with everything we just got through saying about ARDS. The big issue is that it's almost Exclusively related to a dearth of surfactant in a child that's born very early prematurely so 60% of the infants born Younger than 30 weeks when they're not treated with corticosteroids Can die from IRDS In you know using some corticosteroids quite literally dramatically cuts in half the sequela and the problems. And still at 34 weeks, just before 34 weeks, 5% of the infants do show IRDS. So one of the risk factors, premature birth. That's the big one.

The other thing that's kind of counterintuitive, but it's just that it has profound biochemical explanations that make sense. So if a mom is at 43 weeks, God forbid, when she delivers, so advanced gestational age, then you may see IRDS as well. And then in a mom who does not control her diabetes, that's very, very, very high incidence of IRDS.

So other high-risk factors, slide 69. C-sections without antecedent labor. So when I was training to be a doctor in the 90s, if a female wanted to get a C-section at a certain time because, well, hey, in three weeks I'm supposed to go on a ski trip to Vail, Colorado, we used to go ahead and do those procedures. Why not, right?

There's money to be made, and who cares? There is no data about the neonates. Well, now we know that in those situations where there wasn't at least labor started before the C-section, there's a higher incidence of IRDS in those kids than any other group of newborns.

All other things being adjusted as being the same. So now, if you have a scheduled C-section, or if it's an emergency but not like the child is going to come out right this moment, We like to do a Pitocin drip and encourage a little bit of active labor, which causes the catecholamine explosion in the neonate that seems to help preempt IRDS. Perinatal asphyxia, obviously, if the cord is wrapped around the child, or if it's a second twin, and it's the second child, and there's a delay in that child coming out after the first one has come out, because then the placenta isn't... servicing the second twin that great before the second twin comes out. Also, if a mom has had a prior pregnancy where there has been IRDS, for some reason there is a higher statistical occurrence.

Now, that has all sorts of potential ramifications, but the literature is all over the map on what exactly that means. And then, obviously, RH factor incompatibility, that's a no-brainer. The issue, though, is when the child is born without the surfactant or without enough surfactant, it's not the... So you have to replace the surfactant immediately, and you have to administer surfactant immediately.

And how do we do that? Synthetic or bovine from cows or porcine from pigs. The other issues, though, are... Are the tissues involved sufficiently thinned, and are the capillary beds sufficiently matured, developed, and proliferated so that once we overcome the surfactant issue, are those...

other two issues, thickness of the membranes, maturity and development of the capillary beds that feed the membranes. Are those the reasons why there's an issue now? So what happens is a neonate newborn is born.

If a neonate is born with IRDS, they may look cyanotic, they may look blue, and they might be breathing. But what happens is with every exhalation, if they have a lack of surfactant, then the... alveoli collapse at least in certain regions and then they have to struggle to create enough pressure to pop them back open again but the next cycle becomes progressively more difficult which wants even greater pressure generation to pop it back open and so this is a restrictive lung disorder because there's lung collapse and it's very difficult to try and pop open the lungs and why do they collapse no surfactant or inadequate surfactant. And then what happens is if we let it go, then atelectasis progresses to the other parts of the lung and there's profound vascular resistance in the pulmonary vasculature which causes great stress on that newborn heart.

So skipping to slide 74, we have the inflammatory process. Okay so hey there isn't any in the any surfactant or there isn't enough surfactant so the lungs are the alveoli are collapsing upon themselves and at least initially maybe the child's able to pop open those alveoli again struggle um to do that and there's injury and the inflammatory response gets triggered and we're off to the races again so protein deposition etc um what do we do we can administer so you administer um a surfactant and then you give forced inspiratory O2, JETAT-O2, you want to do that for as little as possible, but as long as necessary. And that's a fine balance because that JETAT-O2 creates oxide radicals that can actually destroy the lung tissue and potentially beget lifelong respiratory challenges for that kid.

Early on, how do you know that a kid has armor? IRDS, well, they're using their little ribcages moving in all kinds of strange ways. Their nostrils are flaring, and they have very shallow respirations. The other thing is that the blood pressure drops.

There's hypotension and bradycardia, and I know that that seems counterintuitive, but when there's IRDS and it's spreading through, the blood pressure, So the child is basically going into shock and bradycardia because there isn't enough O2 for the heart. There's edema and obviously the child's body temperature is low. Why? Well, because the heart's not doing a good job pumping the blood everywhere and there's not enough oxygen.

And so it's the blood that warms the body and the heart is going to have a problem if there's no intervention. And in tachypnea, I've actually seen kids, how do you even clock, how do you even time as a medical professional 60 to 120 respirations a minute? But I've actually seen that. So the other thing is slide 76, the frothy sputum, that may or may not happen, but you hear grunting sounds with expiration. Why?

That's the alveoli slamming shut on each other. And you see. awkward or seesaw or paradoxical respirations in the chest.

And it's the same, you know, white-out or ground-glass appearance on x-ray with alveolar edema. Now, here's the thing that's very fascinating. And let's just pause here.

I want you to think about this. So, you've heard of amniocentesis. So, that's reaching a...

putting a needle in ultimately to sample the amniotic fluid and you're looking for a bunch of stuff. One of the things that you're looking at if a mom is going into contraction or if there are signals, all sorts of physiologic signals that we won't talk about, that it looks like the child might actually come out soon and far too soon. You do an amnio and you're looking for a few things.

One of the things that you're looking for is What's the ratio of lecithin to sphingomyelin? And these, ultimately, what you're doing is you're looking for byproducts of biochemical pathways. And if there is enough surfactant...

present. How is that going to show up? Well, we sample the amnio fluid and we see phosphatidylglycerol. If that's present, we're happy.

If the lecithin to sphingomyelin ratio is at least two to one, then the likelihood of getting IRDS is less than five percent. Okay, and if we think that we're in the gray zone or we don't have a choice, fetus has to come out. And what we do is we boost mom IV and we give a massive dose of glucocorticoids right before delivery. And that actually helps to quicken the maturation of surfactant producing cells. And then on slide 79, again, prevention is the key.

We want to administer surfactant. If we have to, that's the next slide. But just administering the surfactant doesn't necessarily guarantee that all is over. Often the child needs to be put on some sort of ventilatory support. Obviously the more premature the child is and with that being the case using mechanical ventilation PEEP or force inspiratory O2 that itself can bring about ultimately mechanical destruction in lifelong respiratory problems.

Notice on the next slide, administering a misogynist surfactant quite literally decreases mortality by at least 50%. That's a major, major, major accomplishment. Supportive therapy on the next slide, why do we do neutral thermal environment so they don't get agitated?

Why do we do minimal handling so they don't get agitated? Why do we care about agitation? Because agitation begets crying, which requires ATP.

which requires O2. So we want to do as much as possible so that the child has as little of a metabolic demand as possible. Okay, so slide 82, pleural space disorders, pneumothorax. So we have the pleural sac that's around the lungs, each lung. Each lung has its own pleural sac.

In the pleural cavity, that's in the pleural sac, there's fluid. How much fluid? Remember, we said just enough.

So what's a pneumothorax? A pneumothorax is when air, for whatever complicated sets of reasons, we'll look at a few, gets into that space. And what can that do?

Well, there goes the negative pressure, the pressure drop between the pleural space and basically the rest of the... pleural cavity, and if there's a tear and air comes in, what happens is it essentially forces the lung to collapse on that side. So there are secondary pneumothoraces, which is what we're going to look at.

Something happens in one region, brings this about in the lung tissue. A primary pneumothorax, on the other hand, happens and arises spontaneously in the lung tissue. There was a young man several years ago, really tall, like 6'7", 6'8", and he was a smoker.

Everything else totally fine. He's perfectly healthy otherwise. He's walking past UNMH and he collapsed and he had a primary pneumothorax.

But if you're going to have one, where is it to have one right in front of the hospital that can take care of you? So he made it through. The bottom line is we don't really understand what the mechanism is, but it's guys mostly who are very tall and who smoke, but are otherwise very healthy. And that's it. So we're going to look at secondary pneumothoraces.

In slide 83, notice there's a list, and there are many more diseases that can bring it about. So people who have asthma, oh my god, pause, just relax. emphysema, cystic fibrosis, infectious diseases like pneumonia, we're going to talk about that. NTB, we're going to talk about that. So what's the big deal here?

The big deal here is that those diseases, whether they're obstructive or restrictive, can potentially cause us to have to accidentally at times jack up the pressure in the pulmonary tissue by doing what? Coughing to clear our mucus to clear the fluids in the alveoli, whatever the disease process happens to be. When we do that, there are structural abnormalities.

Blebs, for example, I love that phrase. There are structural abnormalities. And we all probably have a few blebs on our tissues, thinnings and funky structurings of the pleural sac. And if that ruptures, while air comes rushing in.

And why? Because remember, it's at four millimeters of mercury pressure lower than whatever the pressure is in the lungs and the surrounding atmosphere. So there are catamenial, next slide, catamenial pneumothoraces that can happen that are associated with menstruation, but almost exclusively in people who have fairly entrenched endometrial disease.

So don't... you don't become neurotic about that. It happens, but if you don't have a history of endometriosis, then the likelihood of it being a factor is pretty non-existent.

Then there's a tension pneumothorax, and obviously if there's a penetration wound, a knife or a bullet or whatever, that can certainly cause a tension pneumothorax, but it doesn't have to be non-penetrating. So, for example, people who in this, state believe they qualify for MMA or UFC fighting because they've won a fight or two when they were growing up and they wear some scary tattoo that, you know, to intimidate people. And, you know, you're practicing in the gym or you're practicing in the garage at home and somebody hits you in the chest pretty hard because, you know, you're grappling, you're trying to toughen yourself up or whatever nonsense is promulgated.

You get hit hard enough that can cause a tension pneumothorax. Hey, you didn't wear a seatbelt and you hit the steering wheel when you got rear-ended or when the person in front of you came to a sudden stop or ran the red light. You hit somebody who ran a red light and you hit the steering wheel pretty hard. That also can cause a tension pneumothorax.

So next slide, we've got these weird things called the blebs. obviously if there's a problem with the ribcage, with, you know, there's a structural problem, whatever, but the blood ruptures and air comes rushing in and then the lung collapses. Now listen, when the lung collapses, ipsilateral, slide 86, ipsilateral means same side.

When a lung collapses on one side because of all of these things that we're talking about, that side bulges out because now it becomes, whatever the atmospheric pressure is, it gets filled with that air at the atmospheric pressure. And that exerts a pressure on the contralateral side. So if you do an x-ray of somebody who has had an atelectasis because of a pneumothorax, You see on the film study the deviated trachea and the great vessels, they get pushed over to the other side.

So that's a contralateral tracheal or mediastinal shift. That's a really big deal because that impinges venous return and cardiac output and potentially. It impinges air going into the trachea as well, all the way down to the lungs. And super easy to pop a collapsed lung back into place.

And there's many ways to do it, whatever. Let's look at slide 89. There are people who have small pneumothoraces, less than 20%, so not even a fifth of the volume. And they don't even know. that they have a pneumothorax.

And those you generally don't want to treat because the body's going to be able to figure it out and do the repair. Anybody who's got any kind of substantial pneumothorax, though, is going to have tachycardia because there's decreased lung capacity and there's injury and there's pain. Of course, there's going to be decreased breath sounds and hyperresonance on the side where the lung collapsed because it got filled with air and the lung is collapsed. You can't... put any air in it and it's um sudden sharp shooting pain in the chest These are, so tension pneumothoraces and large spontaneous pneumothoraces are medical emergencies because obviously there's no air and because you have contralateral tracheal shift.

So slide 91, this guy appears in a number of pictures in the book and in my PowerPoint slides, this poor schlub was very harmed and experienced many different respiratory ailments. And so he's very bloated, but he's bloated because he's got edema and pulmonary edema and alveolar infiltrates. So when somebody has a pneumothorax, what do you see?

Obviously, they've lost lung compliance and they don't have an ability to bring air in. So there's decreased arterial load, too, and that's why it's a restrictive lung disease. The chest X-ray, you see a hemidiaphragm. decompressed hemidiaphragm.

So on the side of the x-ray where the lung collapsed, it got filled up with air and it's atmospheric pressure wherever the atmosphere is and that pushed down or deflated or decompressed the diaphragm so that there is no diaphragmatic excursion even possible. And let's take a look at slide 93. It's counterintuitive But you say, hey, I see clear lung fields on the left in that picture. No, actually, you see no lung fields. That lung has collapsed.

How do you know? Well, you can sort of see a dark silhouette that's oblong in there, and that's a collapsed lung. The other thing that you can see is you see a very profound contralateral tracheal shift along with the... main blood vessels that are in the superior mediastinum. For crying out loud, everything looks like it's completely over in the other pleural cavity.

So that's a vintage indicator where the lung was that collapsed. So what do we do with the lung collapse? Well, if somebody has less than 15% of their lung that's collapsed, you don't really do anything. They may not even need to be hospitalized.

It just all depends what kind of pain they're in and what caused the collapse. And if it's up to a quarter of the lung, you can put a chest tube in there, and that helps to radically reinflate, quickly reinflate the lung. You also want to go in and fix the blebs.

And so we can go in and do chemical pleurotesis or... you know use a laser or whatever and what that does is we just do adhesions so the area where the tissue was very thin and structurally weak by frying it chemically or with a laser whatever you cause the development of instantaneous development of scar tissue and that by definition strengthens the tissue there so it won't happen again we can also go in and staple the tissue together Okay, so then on slide 97 is pleural effusion. So pleural effusion, we go back to what I've been saying, how much fluid is there in the pleural cavity? Just enough. So if we ask what's just enough, so in the nepharatis family, because we're all relatively compromised in height, it's probably 5 to 15 milliliters of fluid.

In Shaquille O'Neal, it's probably 5 to 15 milliliters. 50 to maybe 65 milliliters of fluid because his lungs are so big and the whole point of having that fluid there is to prevent the two membranes the parietal and the visceral pleura from sticking against each other and irritating each other causing inflammation and infection and to allow them to be able to move seamlessly frictionless frictionlessly past each other without touching each other Now, the next few slides, transudates, exudates, epiemas, hemothoraces, I don't really care about that stuff. The point is there's all kinds of stuff that could be found in the pleural cavity, and the stuff that can be found in the pleural cavity either has osmotic or hydrostatic pressure that it exerts, and it can keep fluid in the cavity or draw fluid out from the surrounding tissue in.

to the cavity so that there is a persistent elevation of fluid in the pleural cavity. I do actually want you to know what an MP-EMA is, not On slide 100, it's not empanada, but empiema. And that's the one, I guess, pleural effusion that I want you to know.

It's brought about by a bacterial infection in bacteria, released pus, which is filled with protein, and that's an exudate, and that exerts an enormous osmotic pressure gradient to keep fluid in there. So what kinds of things? bring about pleural effusions. There's a bunch of things.

The issue is what happens when somebody gets a pleural effusion. Well, slide 104, the question is begged. It's how much is noticeable before we think about it. So the general rule of thumb is that a person is usually asymptomatic if it's less than 300 milliliters of whatever the fluid is that goes in. So a pleural effusion that...

exceeds 300 milliliters or a spontaneous rapid influx of fluid pleural effusion, those are the ones that are potentially medical emergencies and need to be addressed because it can collapse the lung. So what happens to the person? They get sharp pain that hurts like hell when they breathe in, hence it's a restrictive lung disorder, because if the pleura is filled with fluid, then that means the lungs cannot expand completely, and that's why it's a restrictive lung disorder. And there are few, if any, breath sounds. The more fluid that there is, why?

Because sound doesn't travel through water or through fluid, and so fluid is surrounding the lungs and filling up the pleural sac. That's why there is... absence of breath sounds. Dullness to percussion, same reason.

Decreased tactile fremitus, that's when you have your hands on the person's back and there's no vibrations when they speak. Why? Because again, it's the sound is not able to go through the fluid that's in the pleura that surrounds the lungs.

And again, with a big enough pleural effusion, you can get the contralateral tracheal shift. Why would you want to do slide 107 of thoracentesis? Because you want to figure out what's in the fluid to determine what caused the problem in the first place. And obviously doing a CT scan is a gold standard here also, because that can help reveal what's going on and the details of what's going on.

The big issue, so pleural effusion is big enough as a medical emergency. The big issue for controversy is... that we can do in adults.

We can put a closed chest tube for drainage. Why is it controversial to do it in kids, pediatric patients? Because it's so much easier to accidentally puncture the heart.

I've actually seen that happen. So yeah, it's a very, very, very serious thing. So slide 110, poliomyelitis, we're not going to cover, we're not interested in. Slide 112, Lou Gehrig's disease or amyotrophic lateral sclerosis. That's what killed Stephen Hawking.

We're not going to cover that. And what we're going to do is, that's the end of this particular lecture. This is part one.

Part two will be a much shorter lecture, and we'll finish up chapter 23, restrictive lung disorders.

Transcript for:Understanding Restrictive Pulmonary Disorders

Transcript for:
Understanding Restrictive Pulmonary Disorders