All right, very good. Once again, Carl Warnes, DO MPH FAO COPM is our 1st lecturer. He will be giving 1 lecture on spirometry update for occupational medicine. The 2nd lecture will be challenging spirometry cases for the, for occupational medicine by Carl as a graduate of the Kirksville College of osteopathic medicine with subsequent training and internal and occupational medicine. He's both MD and deal boarded and occupational medicine. Carl has a private practice and occupational medicine based in Morgantown, West Virginia, including occupational and environmental, medical, legal consulting, reviewing coal, minor xrays and spirometry for federal black lung evaluations and aviation medical evaluations. He is, of course, director for the commercial driver medical examiner class. He has nothing to disclose. Thank you. Carl. Okay, thank you very much. I want to thank you as all for for coming. As I'm today, as people probably are aware of St. Patrick's day, if you were really worried about the parade, it's not till 4 o'clock in the afternoon to say, for all of those to all the lectures and you won't miss anything. And since we're at the end of the parade right over across the way here, you probably can stay till the end of everything and still be there before the parade gets there. So you've got plenty of time to get your job. Somebody needs to call the city. Yeah, I'm pretty sure it's a morning break. I'm pretty sure it's early morning. No, no, no. I just looked, I just looked on the Internet says, says 40, it says 48 PM. He's pulling your leg. But who knows what started serving beer at 730? That may be so I, so so I'm going with, I'm, I'm here today in my, in my Livingston tartan tie, which is the clan Livingston, which I think I belong to somehow or another. Okay, so we're gonna talk today about excuse me. Yeah, there's some of that going on too. So we're gonna talk a little about spirometry. And the reason this is the 1 test that many occupational medicine clinics do themselves. Okay, it can be lucrative financially, and it's often you do yourself in your clinic, and you're the ordering doctor and you're also the person has to result the thing. And a lot of people learned how to do spirometry learned about spirometry a long time ago there. It is its own little world that I live on the periphery of because of my work at NIOSH, but what I'm trying to my goal here today is to kind of catch people up from the way you learned about it when you were in medical school, at least when I was in medical school. So, even when I first learned to do spirometry in the official NIOSH spirometry technician class, Jeffrey, you just signed me out of, of Zoom. It says on the screen, you've been signed out because you're currently signed into another device. I still see you you're still playing. Okay, that's good. Let me see if I change the slide. I can't change the slide right now. All right, you should be fine. Am I still okay, Rhonda? You're good. As long as you have 8 participants, you're good or more. Okay, that's fine. Try changing your slide real quick. Great. Okay. So, so this is why this is why I wanted to bring spirometry. There have been a bunch of updates. And we'll kind of go through them, and I'm covering the last 20 years, so 2005, 2017, 2019, and now a brand new one that came out. It's dated December 2022, but was actually released to civilians in January 2023. And we'll kind of work through all of those. I don't have any conflicts of interest that I know of, and I don't sell anything, and we're not going to be doing anything off-label in this class at all. So, these are the different—these are the different updates we're going to review and look at how that impacts your interpretation of spirometry. So, we're going to start with a little case. So, this is the results from a patient. And you can look at what's on the screen, and we'll go to the—just kind of take it in for a second and think in your mind, what is this person's diagnosis? And so, all I want—what's the pattern? Obstructive, restrictive, mixed, or normal? Or an inadequate test? There are the five choices. Okay, does everybody have a plan—have their answer? So, let's go to the next. So, this is—we're going to apply the 2005 assessment criteria for this. So, the FEVC is less than the lower limit of normal, right? The FEV1 to FEVC ratio is greater than the lower limit of normal. So, what's the pattern? That's all you need to do—pattern. Just those two. FEV1 is irrelevant. So, we've got two votes for mixed. Any other votes? Another—is that another mixed? Any other patterns you like from this? Because it's not mixed. That's why we're trying to catch people up. So, it's—yes, we've got restrictive and obstructive both in the room. So, this would be—because the FEVC is less than the lower limit of normal, and the ratio is greater than the lower limit of normal, this would be a restrictive pattern. Okay? The FEV1 is unimportant at this time because, if you really think about it, using the ratio compensates for restriction, right? Yeah, the FEV1 is less than the lower limit of normal, but we don't really care because they've got a low FEVC. So, the total is less. The first second is going to be less, and the ratio manages that for you. Okay? So, I keep going on, and I go, okay, I have more information. I did the full lap thing here. So, I've got lung volumes, which is greater than the lower limit of normal, right? So, this is a—so, it's not true restrictive disease, okay? And he's got an elevated residual volume. At 121 percent predicted. So, this is actually pseudo-restrictive disease. This guy's got a little bit of air trapping going on. That's actually what you're seeing here. But I just want to—so, you've got to kind of—it's like, how do you flow through these things, and what's important at this—but the reason I'm doing this for this group is people who have been doing medicine for a long time is this is—the recommendation for how you interpret this has changed since—in a lot in the last 25 years. And so, what you learn when you're a student is not the way we do it anymore. You've got some mild air trappings. It's not really true restrictive disease, but it's still a restrictive pattern. So, if all you've got is basic spirometry, it's a restrictive pattern of spirometry. A little bit about—so, we're going to start with the super basics for anybody who doesn't do spirometry or isn't familiar with this. So, when you do spirometry, you get two different kinds of curves. You get the volume-time curve. That's what I grew up with. When we—when I took my first spirometry class, we had the dry rolling seal spirometer and a pen you had to put in in a certain way, and you had to make sure you had the timing set correctly on the chart paper that physically went through the machine, and the pen went up as pushed by the bellows on the dry rolling seal spirometer. So, that's what I started— that's what I cut my teeth on a long time ago. We now have flow volume loops, which is—because everything now is computerized, or at least—is anybody still using a dry rolling seal spirometer with chart paper that moves? Okay, I didn't think so, but even NIOSH is finally, 25 years later, starting thinking about getting rid of their dry rolling seal spirometers. They won't do it yet, but they're thinking about it. It's the government, so everything's slow. And that comes in two varieties. At the top, you'll see one that's just showing the expiratory phase. That's all that's currently required in spirometry, and the one on the bottom shows—also shows the inspiratory phase, which they would like us to get along to using at some point. We'll talk about that more. And some spirometers do both and then only display the top, and it's a little confusing. Your spirometer, unless it's old, will probably do more than it's turned on to do right now if you just made it simple, which is okay. So, when you blow out the air, this is a traditional volume time curve. And so, the FEC is just the highest number it got to where it plateaued. So, for this person, it would be, I don't know, someplace around 3 liters. The FEV1 is how much air they blow out in the first second. So, I've got that time across the bottom. I draw a line up at 1 second. I draw back across to the axis, and that's, I don't know, maybe 2.7 liters. So, that's what FEV1 and FEC are. How do you calculate a ratio? Biggest FEC, it's from a valid curve, biggest FEV1 from a valid curve, and you do math. It's just, you just divide the liters for the FEV1, divide by the liters for the FEC, and you get the ratio. And it should be from the largest valid curve. And how to determine a valid curve is going to get more confusing in a few minutes, in about 20 minutes. But right now, just go with that as a concept. I don't recommend, and in fact, since 2005, 2017, 2019, and 2022 recommendations all tell you do not calculate the percent predicted for the ratio. It's already a percentage. Just get used to about 70% is normal, or 80% is normal. Don't try to calculate the percent predicted of a, the ratio of a ratio just causes confusion. It does not help anything. So, just don't even look at it, and they recommend not even calculating it. Okay, so how do you, how do you do this, the patterns? So, when I went to, when I took all my classes to first learn how to do spirometry, anything between 80% predicted and 120% predicted was normal. Okay? You didn't need to do any more. That was normal. So, in 2005, okay, keep in mind that's 18 years ago now, or 17 years ago anyway, Pellegrino, then this is the ATS recommendation. It was a bunch of papers about spirometry that all came out in a, like, they divide a spirometry, and the Pellegrino one is the one for interpreting simple spirometry. There's another one for how to do lung volumes, another one for how to actually, you know, to do all the different parts of lung testing. We use the lower limit of normal, which is the fifth percentile to determine what's a normal value for that person. Now, the one thing that got lost in that translation was somehow this became a hard and fast number. If the lower limit of normal is 2.13 liters, anybody with 2.12 liters is abnormal. Well, keep in mind, this is, this is where this, I fight this at NIOSH all the time. That's a fuzzy number. Not, I'm not picking on the number itself, but it's just like somebody's CBC. And if you're looking at the normal range at your hospital is from 13 to 17, and the person's 12.9, you don't get super excited. Same, do the same thing here. Okay? Use your doctor skills to say you're so close to normal. And remember, the low limit of normal is the fifth percentile. So, we've already said 5 percent of people who are normal will be below this number. So, let those people that are really close be normal-ish. Don't get, don't get yourself super excited by that. So, this is the lower limit of normal drawn. There's about 22 different ways to draw this picture. So, the lower limit of normal is, it's one, it's, it ends up being 1.645 standard deviations below the mean. Okay? And so, that's where you get the fifth five, the fifth percentile. I really wish that whoever it was that made C or T, was it made the Z-squares, could have made it, like, two. Because that would be so much easier for us doctors to deal with. Remembering a three-digit number is really hard for us. So, I think it may just, like, two and less would be, minus two or worse would be better. That's not what we got. The one thing I want to, the reason I'm pointing this out is, if you look across the bottom, there's kind of an interesting conversion here because you can see the different likelihoods of this, of how likely this is to occur in that patient. So, it's a one in 20 chance a person's going to be worse than this if you're using the 5 percent or the 1.64. But when you get down to, like, a Z-score, like, when the first percentile is one in 100, this kind of shows how uncommon you are when you get from normal, when you get further down the chain. Also notice that there's, this is all focused on Z-scores. The Europeans have switched over to using Z-scores for this. The Americans have not just yet. But there's more and more emphasis on switching over to Z-scores, and we'll talk about that in a few minutes. Some of it makes sense and some of it does not, in my personal opinion. They're trying to confuse us. So, this is the comparison of the lower limit of normal, which is shown here in blue, with the 80 percent cutoff, which is shown here in bright green. The red is the predicted number. So, when you look at the chart, you'll notice that when they're a bit younger, the lower limit of normal is actually higher than the 80 percent. It might be 83, 84, 85 percent. And when they get to be older, it's lower, maybe 77, 75 percent. So, just keep that in mind, that it's not, 80 percent is not, it's kind of in the neighborhood, but it's not the same. So, where can you get lower limit of normal data? Most everybody's barometers will do this now, unless you've got a, you know, one from their, if you've got one from prior to about 2008 that you're still using, it may not be capable of this. If it is, just turn it on. If it's not, what you can do is you can, there's a couple of online calculators. The NIOSH website has one that'll do both Knudsen and NHANES, which is the U.S.-based data set. Actually, it stops at the age of 75, which is really frustrating. If you go to the Hankinson calculator, it'll go, it'll go to any age, it doesn't care. And Hankinson did the work for NHANES. It's there, it's that we called NHANES, and NIOSH, and inside CDC, it's called the Hankinson numbers, because he did the work for, as one of their people. The other, the Global Long-List Initiative also has an online calculator that's, that is actually pretty easy to use, and we'll talk about, more about GLI in a few minutes. So, you, this, there's different ways to think about this. If you like flowcharts, this is the flowchart version, you know, where this one starts with both the ratio and the FEC, because that's all you need to get patterns. And you can follow that through, and if you, you know, if everything's normal, you're normal, and, you know, this will take you obstructive into mixed, into restrictive, you know, following a flowchart, if you like flowcharts. We, they recommend using this characterization, the upper right-hand corner of the screen, of, of the severity. And you, and the only thing you use FEV 1% predicted for is severity. So, you know, so anything more than 70% is mild, and get down to less than 35% is very severe. So, this is the one place where we do use the FEV 1% predicted. If you like it in words, this is the word version of the same thing. AECOM does, goes through the logic a little bit differently than the original paper did, but the outcome is always the same. It's just that AECOM wanted to write it out in words instead of using a flowchart, just to, I guess, to feel special. This is from the original document, and so if you, if you want to do, be more precise in your diagnosis, you know, and you get lung volumes in DLCO, this will, this will allow you to get down into a disease family. And you can see, like, is it pulmonary vascular problem? Is it neuromuscular? This can kind of get you into those. Again, this is a guidance. It's not absolute, but this can be useful guidance for people as they move through those diseases. Okay. Anybody know about gold criteria? Does anybody use it clinically? Really? 24, 24 karat gold's best, honey. It's a little salt, little honey. Yeah, that's true. Got a little nickel in it. Anyway, so we're talking about gold criteria, because this is, this is, when I have to, when I do the same, if I had the same discussion with people with family practice background, they all, they want to live and die by the gold criteria, live and die by the gold criteria, which drives me nuts. Okay. So gold is the global initiative for chronic obstructive lung disease. And, and, and, and their, their, their, what do you call it? Divine doc, divinely released documents. It says that the presence of bronco, of a post-bronchodilator FEV1 to FEC ratio less than 0.7 confirms the presence of air flow limitations. Now, so what they're saying is, is you do a post-bronchodilator ratio, if it's less than 0.7, then you've, you've got a problem. From a, from a treatment perspective, this is actually not horrible. So if you want to look at, if you want to decide if somebody's treatment for their lung disease is adequate, this is not a bad way to think about it. And I will give them credit that if you look at their treatment recommendations for the people that failed simple treatment, they're not bad. Now, the one thing you have to know about gold criteria is that the gold panel is 100%, not 90%, a hundred percent people who are being paid by pharma. Their goal is to make sure that we get every human on the planet on some sort of inhaled respiratory medication, or at least as many as we can get there. And so they make it clear that, they also say that this, they, if you read the really small writing, it tells you it's not diagnostic criteria, but there's a lot of family practice people that kind of missed that step. So the, an FEV, a ratio, FEV1 to FEC ratio less than 0.7 is not diagnosed, diagnosed, stuck of anything. And the family practices, practice and people have concluded that, that since it's how you guide treatment, it must be diagnostic of COPD since these are the COPD people. I want to show you here for, just for a second. So this is looking at the ratio using the NHANES dataset, okay? And in the red or orange, whatever you want to call that, the lower road, lower line, that's the lower limit of normal. So that's the LLN. This is the 70% cutoff recommended by our friends in the GOLD committee. So everybody who's in that green box, we're going to miss their diagnosis. You're going to underdiagnose, if you use 0.7 as a hard cutoff, you're going to miss those people's lung disease. More importantly for the people on GOLD, if you, all those people in the yellow box, because if you look at that pretty carefully, the ratio, the lower limit of normal for the ratio for a 75-year-old is like 0.63, 63%, okay? That's 7%, that's 7% of those people that are going to be recommended a medication that they don't need because they're normal that are getting prescribed a medication that the pharma people would just love to sell you. So this is, I think, where the driver is for this. It's not diagnostic of anything, and you can disabuse your mostly family practice people. I've seen pulmonologists fall in this hole too, that they've decided anything with ratio less than 0.7 is COPD, and it's just like, what? And it's bad. It's good marketing, bad medicine. The only good thing is to date, I'm not aware of having a respiratory medicine prescribed that costs, other than making your wallet thinner, that costs $1,000 a month isn't going to kill as many people as what Purdue did, but it's the same kind of a thing. We're over-marketing, we're making more people need our medicine than really need our medicine. Okay, a little bit about, I'll come off that horse now for a second, a little bit about predicted values. So basically to make up a predicted equation, they take a bunch of people that we think are pretty much healthy and have them blow into our machine, and we measure their values. And then they take those people and they kind of do math on that to draw curves and things along those lines. Up until very recently, the inputs would be age, height, and sex or gender, and most of them did something with ethnicity, and that varies somewhat. There've been a lot of them. These are the U.S. ones. There are many more around the world. I can't find it anymore, but when I took my spirometry class in 1998, the first time I ever took one, they had a book. I mean, it was like the Sears catalog book, because that was when everything was tables. And it was tables from all over, like a global collection of these tables from islands off of India where some doctor got a spirometer and did this for the people on his island. And there were like 20 for India, and there was a bunch for China, and they would just make up a table for their community using the same process that they used for these ones for the United States. These are all U.S.-based ones, mostly. And how many people still have – I still see it in some spirometers where there'll be a choice of something called USA, or USA slash Newtson-Morris and all these weird things that don't really exist. I recommend against using anyone that does – there's no reference. We just took all the USA ones that happened together and divided. Let's not go there. So what about the newer predicted equations? So I cut my teeth on Newtson-76, because that was what was – if you kind of think of the history of all this, the cotton dust standard is what made them standardize spirometry. And that was based on Newtson-76 up until about two years ago. Now, they actually upgraded to NHANES – like, the federal law changed about two years ago to move that to using NHANES, so the cotton dust standard. And that was based on 746 non-Hispanic white Americans who were not pregnant, which is not a huge big number. Then they did the NHANES-Hankinson thing that was done as part of the NHANES surveys, and they did about 7,500 people. They came out with numbers for Caucasian, African American, Mexican American, and decided Asian was 88 percent of Caucasian. And then we now have GLI, or the Global Lung Initiative. It's new. It includes about 74,000 people from around the globe, except around the globe is kind of not really the whole globe. And I need to—if I had more time left, I was going to make a map that shows this. So, it includes—they decided that Caucasian and Hispanic or Mexican American were not different enough to warrant having its own thing. And quite honestly, they were probably right. And the thing they were right about was there aren't enough Mexican Americans in the data set to probably justify it being its own thing. That probably is true. African American, Northeast Asian, which basically means Japan or Korea. Southeast Asian, which is China and kind of down towards Vietnam and Thailand and that whole area. I need to draw this map because it's not the whole world. The thing that's interesting to me is—and then there's other or mixed—they took all of them together and just homogenized the whole thing. The thing that's interesting to me is the only data set they have for people with black skin was African Americans from the United States. The entire continent of Africa couldn't find a data set that they thought was done well enough to be brought into the system. Do you have a question? You just answered. Thank you. Yeah. So, African Americans, all you get. There's no African. What about blacks from Australia or from the islands? So, the one thing that they did—and this is where the recommendation is right now—is if somebody does not precisely fit into one of the other categories. So, if they're not Caucasian, African American, Northeast Asian, or Southeast Asian as they've defined it, use other. Other is they just added them all up and divided. All these other ones, everybody counts. So, at least there is a current recommendation for what you do for somebody, and what do you do with Barack Obama? Like, when do I use? And so, now there's a recommendation to use other for people that don't fit in one of those categories. What about India? I'm back to my, yeah, they have a lot of data sets. I don't know why that's not its own thing. And I'm not sure if they're in Southeast Asia or not. And that's one of the things I need to look up. I know who Northeast Asia is, because Southeast Asia is a bunch of countries, but not all of them. Yeah. Since height's in there, why do we even need a construct of ethnicity? So, the question is, since height's in there, why do we need ethnicity? Hold that thought for about four slides. Okay. Okay. We'll get back to it. Okay. So, here are a bunch of, here are the FEV1s for a bunch of different predictive equations. They all follow kind of the same trend as we go through life. And this is for some, it's the same height as they, and same gender as they age. You'll see some of them are a little, you know, more, a little lower when they're young and higher when they're old. And the one thing I want you to notice, and we'll, well, we'll zoom in on this just a second, but almost all of them have a knee. They go up to a certain point, then they decide you're mature, and they start falling from that point. And that was to make the math easier for the math people. Okay. GLI used, and I'm, something about double spline, something that I don't understand. And so, what they ended up with was a curve, not a knee. So, this shows, like, you can see that Newtson 76, that knee was at the age of about 24. Nhanes, the knee is about 20. And then GLI, which is that gold or yellow line going through there, it kind of curved all the way across. Yeah, that's a one minus e to the negative alpha tau power. Sure. It has something to do with double splines that I don't understand. I have no idea what they're talking about, but it's a, it's a smoother curve. It doesn't, it's not a straight line with a knee and then a straight line going the other way. All the other graphs are a straight line with a knee and then a straight line going the other way, right? That's how all these, all the other ones work that way. The only reason it looks weird for Newtson 76 is because they split the difference for the year that they couldn't decide where the knee went. That's why there's a weird bump there. So, racial differences, okay? This has driven researchers nuts since 1869. Right after the Civil War, there's this really cool thing, and it's available, that they did where they were looking at everything. They were trying to, remember, we're still in the time of descriptive science, and they were trying to catalog everything you could think about, about people. And there were a lot of people who had served in the military who were Black, which is the first time that Black people interacted with white people in a lot of those settings. And this is for this, in the Civil War, they were, and so they were still in the military for a while after they were done fighting the war, because they weren't quite sure that they were really done. And they had to deal with prisoner of war and all this kind of stuff. And so, they had a bunch of these people, and they had a bunch of doctors, and they started describing things. There's descriptions of hairiness, comparing Black people and hairiness of white people. And they would send doctors down to watch them swimming in the, bathing in the river and stuff. And they had grading scales. And one of the things they did was they created what I would call a primordial spirometer. They used a meter that was used to meter gas, like going into your house, which was just starting to be a thing back then. And I had the people blow into it. I mean, the units of measure are like, I don't know, cubic inches per furlong or some damn thing. But it was weird use of measure, but they were starting to do spirometry. And what they realized was that Black people had, for the same height, had smaller lungs than white people did. Now, they use the word inferior, which drives everybody nuts. They were just talking about a smaller number. I'm sorry, is there a question online? Okay. So, they found that was true. The osteology, when you compare skeletons, people from African descent have skinnier chest cages than people from European descent who have rounder chest cages. That is a true statement. They've tried correcting for seated height. They tried correcting for standing height. They tried correcting for wingspan, and none of them fixed the problem. One of the problems with seated height is you've got your noggin on top, and there's no good way to do seated height to the shoulders. That's apparently a hard thing to do because people have rolled shoulders and square shoulders, and it works. They've tried that, too, and they have not yet found a workaround. It will not surprise me if five years from now we're using tibial length divided by earlobe width or some damn thing as a way to calculate this. If you look at total lung capacities, it fixes the equation. We don't have a good workaround for this yet. There's a committee at NIOSH that's working on it. If you read the ATS things, which I'm sure everybody here reads as they're falling in bed every night, there are multiple comments on this exact topic of how do we deal with racial correction and how to do it best. It's an active concept right now. I'm going to set it so that folks can't just unmute themselves because we have a participant who likes to remain unmuted. Is it possible? One of the things that came to my mind was that the difference after the Civil War was due to, and I'm going to oversimplify it, that the former Black slaves who worked in the cotton fields had cotton dust etiology of a decrement in their vital lung capacities. The question was, were the African American lung volume or spirometry different because of cotton dust exposure? Interesting question. The difficulty with that theory is it's still true today. There are fewer African Americans working in the cotton fields today. I don't think that's the whole thing. I'm messing you up here. I'm sorry. That's okay. We've had a whole variety of different ways to do ethnic correction. Sometimes it's a fraction. For Knudsen, African Americans were 85% of a Caucasian. That's just the way they did it. Key point with Knudsen, when they said it's 85%, their data set didn't include any African Americans. They just made up a number and said, yeah, it's smaller. I'm sure cigars and smoke was part of that discussion and that decision. I mentioned before, GLI recommends for multi-ethnic patients to use other. There are people that just say, I just use other for everybody. We don't mess with that. Just everybody's other. At the end of the day, genetically, that may not be that far off. We may just all be mutts. It may just be easier to just mix everybody together and just go with it. If you're going to do that, though, you have to expect that people with more European ancestry are going to have higher values than people who have African ancestry, more African ancestry. I don't know what the right answer to this is. This is an ongoing thing. Some of this is right now, if anybody else works in the federal government, they're having a hard time right now with the concepts of ethnicity and gender. The federal government wants to have one description of ethnic groups and one description of gender. Both of those are in these bizarre committee things. We're not allowed to do anything in these areas until they figure that out. Then we can follow that pattern, whatever that ends up being. So that's a coming attraction. The current recommendation, if you're doing a workplace program, now this is ACOM and ATS disagree. ATS says use GLI for everything. ACOM, in their most recent publication, still recommends using NHANES because it's the most American-ish of the ones you might want to use. Also keep in mind, it does include Mexican-American, and if that's a large population where you are, that might be another driver to use that. It's interesting, one of the PFT labs, they use GLI for everything except Mexican-American, where they use NHANES Mexican-American. I'm not going to defend it, but they have a large Hispanic population in their area, and that makes sense for where they are in New Mexico. Key thing is, if you're doing a workplace program, you might give people a list of what they can choose from, but once they choose, it never changes. If they self-identify as African-American the first time, they're African-American for the rest of their career. Otherwise, you'll go nuts when you're trying to compare them over the years because their numbers will keep changing. What about standard or seated? Well, all the NHANES data was done standing. The ERS and ATS recommend seated. ACOM still is on the standing thing. If you go to a real pulmonary function lab and you ask a respiratory therapist that runs it there, they've probably never done standard spirometry, and some of the devices won't even allow it. The one clinic I go to, to use the spirometer—actually, both of them now—to use the spirometer, you have to sit in their body box. Now, it has a way you can kind of turn it around if the person can't even get the body box for somebody in a wheelchair, but it won't turn around and go high enough to stand. That's not a thing for that device. GLI is completely agnostic. The one thing you have to know is that when you're standing, your lungs are a little bit bigger than when you're seated. If you're going to do follow-up spirometry over time, if you're going to make a change, make a change for everybody and no seated or standing on the record so you know what you're comparing to. So what about reporting the results? Remember, a lot of us do our own testing. I've said it before. Don't report the percent predicted for the ratio. Just report the ratio and stop. They recommend great caution using that low limit of normal as a dichotomous key. For more than this, you're bad, or less than this, you're bad. If you're more than this, you're good. They strongly recommend that we instead use it. Think of it as a concept. They recommend instead of putting a line on the report, put a star. Kind of gives you an idea that, you know, gives you an idea where the marker is. Then you can say, well, jeez, they're so close. They're still on the star. They're probably okay. They recommend reporting z-scores, something that we in the U.S. are going to have to get used to. Apparently, they're used in a lot of testing in Europe now. Like, if you get a CBC back, it comes with a z-score, not just a range of normals. The report grades separately for FEV1 and FEC. Some software does that. Some just grades the whole test. Then they added the quality of E, which is a single acceptable maneuver. Because we had trouble getting, if you can't get, if all you've got is bad maneuvers, you just have no report. You can't report anything. They're now allowing you to report a single maneuver. What we do at NIOSH, we report single maneuvers that are normal, as normal, and normal but not repeated. But we still don't report. We won't give you an abnormal based on a single maneuver. Yes, you have a question. I frequently see FEF2575% less than 80% predicted. So even though it interprets it as normal, I read it there saying that they could have an early obstructive process. So the question was about FEF2575. The funny part is that nobody knows what to do with FEF2575. I don't even know if you said you marked it as early obstructive. That might be right. I have no idea. That literature is all over the place. And I'm intentionally not getting into that because it will make our heads hurt. And there's no conclusion, which is even worse. Because you'll see, if somebody likes it, the next person thinks it's horrible. It motivates smokers to quit. If you want to use it, yeah. And he said it motivates smokers to quit. I agree. Anything you can use on spirometry or any other test that motivates smokers to quit, I give you full permission. Please continue to do that. That's where the lung age came from, which actually is very effective, but it drove the pulmonologist nuts. Lung age, what they did was they took their results and then went backwards into the table for FEV1 and said, how old would you have to be at your height to have lungs this bad? It was incredibly motivating. So in a primary care setting, it's actually not a bad thing. But it will drive the pulmonologist nuts. But if you're using it just to get people to stop smoking, have a good time. I think that's fine. Okay. And we got that. So in 2019, they redid, basically, from stem to stern, that 2005 paper. And we got the new one. Graham was the author. It's ATS-ERS, joint statement of a standard that we all agree on. So the overall goal of the testing session did not change. We still would love to have three maneuvers, two being repeatable for FEV1 and FEC. And the testing rules for the technicians, recommendations, what they're supposed to do, did not change. What it did do was give us, the interpreter, the ability to work with less-than-perfect testing and still come out with a conclusion. Because if you followed Pellegrino strictly, if there was a cough at three seconds or their back extrapolated volume was too much, then you just had an uninterpretable test. You went into uninterpretable if you didn't get at least two acceptable maneuvers. The whole thing was uninterpretable and you got nothing if you followed it strictly. And we know that's not helpful clinically. I mean, ordering a test and saying, I don't know, is a bad outcome unless you think the person's playing games. And then that's a fine outcome. But if they're doing their best, we know that even in the best hands, up to about 10% of sick people, and so the sickest ones, can't do good spirometry in quotes with everything perfect. And it's not because they're not trying. It's not because they're not motivated. It's because their lungs suck and they're barely breathing at all, let alone being able to do this weird maneuver to blow all their air out in the first six seconds or 10 seconds. So they want to be able to not have all the people with bad lungs having uninterpretable results, which is where they were ending up because they couldn't do the weird maneuver. So we have more alternatives to still have an interpretation for these folks. So the maneuver hasn't changed. Some interesting wording they included. I personally like the fact that when you have them inspired completely, they should look vaguely uncomfortable. If they look happy, you're not doing it right. They need to breathe in deeper. The other thing was that then you're going to have the person then blow out as fast and hard as they can. And then you have them breathe back in at the end of that maneuver. So you end up with a curve about like this. And the goal is to get back to that inspiration at the end to show that that was full of their full volume, that they should line up. And that little space there should be less than 200 milliliters. That's ideal. This is recommended, not required in the 2019 paper. NIOSH is trying to start doing this. In the summer of 2020, we were going to be doing this on all of our serometry. Our question is, is this achievable in normal people? Because we don't know. And the study they based this on, they based this on how the machine works, not on whether people can actually do this. And the point that 200 milliliters was again in this, well, okay, it was in Europe, a smoke-filled room with wine and stuff is where they came up with that number. So in 2020, we were going to do this with all of our coal miners. And we typically survey about 4,000 coal miners a year. And we have a data set. You may have heard there was a little disturbance in the forest since 2020. And so we're still waiting to get that done, maybe this summer. We haven't done spirometry since 2020 because we couldn't figure out how to isolate enough and put enough protective stuff to protect the workers from the people blowing out because you can't wear a mask and blow into spirometry too. That's not a combo that works. And the federal government has been super paranoid about this. So we'll see how that goes. And if we ever get to collect the data, that will get published. So we'll let you know if this actually is achievable or not. So the whole idea of there's acceptable curves, which means everything looks right according to the way ATS wants a curve to look. And then there's usable, which means I can still make an interpretation even though the curve may not be perfect. So maybe some people have problems at the beginning and I can still use the FEC, or maybe people have a problem at the end, I can still use the FEV1. And that's to allow us to still have a result. So there are some things that are still fatal flaws that you can't fix. A leak at the mouthpiece, you're done. A zero obstruction of the mouthpiece, obstruction of either end, and a zero flow error. If any of those things happen, you're done. You really can't interpret it. You can't undo this problem. So we're separating the thoughts about whether I can use the FEV1 from whether I can use the FEC. And we start by looking at, for the FEV1, I look at the volume time curve, which is where I always want to start there because I'm more comfortable with it. Does the effort look good? Is the back extrapolated volume okay? And I don't care about the end of test criteria because it's FEV1, right? The flow of volume moves. Is there a cough? Is there any problems I need to worry about? If the first second looks good, that FEV1 is valid. I can use it. Use kind of the same process for FEC, look at – I'm looking at the end of the thing. I don't really care about the – if there's back extrapolated volume problems, I don't really care. And I'm really looking kind of at what happens mostly after the first second. So if I can use the FEC or not from that maneuver. The glottic closure is one of the things that we mentioned here. That's one of the things a lot of people miss. That glottic closure is when we get a strict – a hard corner. Like, you can especially see where those red arrows are in the flow volume loop or curve. And if you – because if you see that, now – I don't know what would have happened beyond that. And that's so the FEC would not be usable in those cases. And I just put through that because a lot of people don't know what – everybody's heard of it, but nobody knows what it looks like. So back extrapolated volume, basically, I'm worried about that little bit there that they blew before they started blowing hard. And most people have a little one. Just as you're – as you're transitioning in your mouth from I'm not blowing to I'm blowing, there's a ramp up there. And they want that to not be more than 0.1 liters or 5 percent, whichever is greater of the total FEC. Now, this number has changed a lot. And we'll see this in a couple minutes, where it's vacillated between 0.1 and 0.15, on and off, and on and off, and on and off. But remember, this affects FEV1. It does not affect FEC. So you can still use the FEC even if you've got a back extrapolated volume problem. So end-of-force expiration – remember, when I took my first class, how long did they have to blow? Anybody? Six. Six seconds. Six – if you got to six seconds, we are good. We can stop. We're not doing that anymore. So your choices are either they get a plateau, and you can tell them to stop after they've got at least a second of plateau. They get to 15 seconds or at least 12 seconds. Some machines stop at 12. That's enough. But for the people that are air trapping, they may still be going up at 15 seconds. And that's fine. Let them keep blowing until they get to – at 15 seconds, tell them to stop, because otherwise they're going to pass out on you. And – or you've got – and this is the one that's the hardest to implement but sometimes useful. The FEC is within repeatability tolerance of or is greater than the largest prior observed FEC. So this is intended to give you something to do with people with horrible lung function testing. If their crappy-looking graph is as good as it was six months ago, you're good. You can compare it to a prior test session and say, yeah, you were 1.7 liters last time. You're 1.7 liters now. We're good, even though it's an uninterpretable graph. I've never used that, but it is an option, and it might apply to your sickest patients. Can you repeat what you just said about it's a poor test, but you can accept it? So, this is the third option for end of forced expiration is the FVC is within the repeatability tolerance. So, point up up to 0.25 liters of or is greater than the largest prior observed FVC. And they mean in a different test session, like, when they were here 3 months ago, what was it? You can, if they did better than their last time, or they're the same as their last time, you can still interpret it. Some. Okay, so, spirometry quality reporting. This is the 2019 ATS system, and you'll see that you can go anywhere from 2 to 3 maneuvers. And then what the repeatability is, and this is for people over the age of 6, under the age of 6, it's way different. And so you can, but you notice that we've now added the grades of E. Which we just have 1 acceptable maneuver and obviously you don't have to worry about. Repeatability if there's 1, because it's. It's 1, we've also added you on. You, which is a usable, but not acceptable curve. And then, of course, we still have F, which is nothing. Usable this is this is the, this is the time chain of ATS numbers, which kept changing. Then we've got NIOSH. More back to ATS again, and if you look at the BEV on there. It keeps changing between 0.15 and 0.1 and 0.15 and 0.1. It keeps going back and forth. I don't know. I don't know that makes any difference. Okay, so 1 of my recommendations, though, is if you're going to provide the report back to the worker. Specifically the worker, you may want to think very hard about putting quality. Quality on that report and what I mean by that is, what do you what does it mean to the worker when they get back a thing that says that their lungs are quality D. Yeah, they're almost their lungs almost fail. And this has nothing to do with their lungs. It's only the quality of the test, which has way more to do with the technician than it does with the patient. And it's certainly not, I'm not grading their lungs and grading their the test. And so it's useful for us when we're looking at the test to think about that. It is not helpful to the patient. Like, do they need to up their life insurance? Because they've only got quality D lungs. In this 23 year old, so I recommend admitting spirometry grades from the report you sent to the. Worker or the patient, because you just causes confusion. They know a is good and D and F is bad and they don't understand that we're grading the test. Not them. I was talking earlier about this, this acceptability, usability and repeatability. They're different. So, acceptability is, is the curve? Okay. Repeatability is to the 2 curves match and the numbers they came out with. And usability is, can I get anything at all out of this 1? So, um, and if you kind of look at it for, like, in this particular graphic show for the, for the, for the. End of force expiration indicators, I got to have it for FEC, but I don't need it for the rest of it. And so I don't necessarily even need it for usability. Some people, they get to 12 seconds with this thing just keeps going up. They're never going to plateau. Like, you could have them blow into the machine for a day and they will, it still won't plateau because there's still there's still air trapping. But it still might be usable even doesn't meet acceptability criteria. This is an example of 1 of those curves. This is this is 1 humans testing from 1 of the spirometry that I did. Yes, sir. So the quality isn't for. You do quality you can so the way. Is there's a quality for 1 and a qual and. A quality for separately. They're separately graded. Does that make sense? I just always thought it was that you wanted to see a little cost to line up. Well, so, but the quality has to do that. You were talking about you were asking about whether there's abnormalities in the graph. In the curves that what you're talking about, though, is acceptability. Just different repeatability is, do they are the values the same and sometimes they can have a little cough and still have repeatable values. That's actually not necessarily a hard fail. But you, you don't you. And they said, but repeatability has to do with how close are they or how consistent are they. Acceptability is things like bumps in and lines going the wrong way and stuff like that 2nd, brass and all that. That's all an acceptability. So, this is this is just an example of somebody with air trapping and you can see that on some of the lower ones, they're blown out to 12 and 15 seconds. They never achieve a. Plateau, because they're, because they're air trapping and air trapping and more air trapping. I said, don't take people past 15 seconds because you will make them pass out. This is this is from actually. This person, this is the computer print out and you'll notice that in my error. Well, we'll do a couple of it. So, back is rapidly to volume is all less than 0.0. it's less than 0.1. so those are all. Okay. I don't have to worry about that. Now, the computer tells me that I have end of maneuver problems. I'll just trust me and is end of maneuver. So, it doesn't think we met end of maneuver criteria. Keep in mind. That's the, that's the graph that they go with. The report goes with none of them plateaued. So, the computer is going, well, you didn't meet criteria because you didn't make end of maneuver criteria. Well, these are both these are all good legal maneuvers. The computer is being stupid. It's not perfect. But it's, it's the physiology of the patient. So, does it repeat? Is it repeatable? Yeah, if the highest and lowest are within 0.25, which is that it's the worst repeatable version, but it is repeatable with a grade of C. And that's for the numbers is the FV1 repeatable. Yeah, it's all between 0.62 and 0.63. so that's way less than any that's that's actually a grade A for the FV1. Any questions about all this, how this kind of all works to think about it. Most of the time, the computer will grade it itself. A lot of clinics have turned that off because they don't want the. They're their customer to go. My God, you've only got grade C spirometry. Why didn't you get grade A? They just turn it off. So then most clients can't they can read the grades. They can't they won't do the calculations figure out themselves. A little bit about serial spirometry in the workplace setting. This may make sense. Unlike in here in conservation, we follow people over time and look for standard threshold shifts. It probably should be if you're in a workplace where you've got exposures that could be causing. Changes in spirometry, either asmogens or other. Problems like that, we do recommend using serial spirometry. It will help you. And it'll help the worker keep in mind if most people, as long as it's above 80% predicted or below the low limit of normal, they're fine, leave them alone. Well, that's okay if the patient, if everybody started it, not 85% predicted, but if the person started at 120% predicted, and then they slowly drifted down as their lung disease got progressively worse to before they get below 80% not going to do anything is probably not. It's probably too much variation to allow it to happen before you do anything about it. So, the has a method. I would, and I like to do it. Kind of. I like to follow their method. 1, where you follow the change in percent predicted and what you're doing is you're letting the spirometer do the correction for age. Because it's going to look up a different number on the predicted equation and do that math for you. You'll have to do 1 calculation. If you want to follow the actual volumes, you can do that as well. But then you have to include the age correction and do it by hand. Which is less fun. Question in the chat, I know you're going to take a big one. Sure, I'll have chat on the screen. Okay. No worries. Okay. Uncle Jeff will help you. Thank you. Right here. Okay. So the question that was asked was. What do you do with the Z score? Do you just treat that as a new low loan of normal? Give me about 3, 4 slides from here and we'll come back to that. Does he scores come back in just a 2nd and also for those of you in the virtual environment. I've disabled your ability to unmute yourself. So, at the end of each module, we'll give you an opportunity to ask. Audible questions, alternatively, you can, you can raise your hand and we'll unmute you. We just don't want folks to inadvertently unmute themselves. Because sometimes we could hear CNN in the background. Okay, so. So, there's a fair amount of. Research in normal variable time. Yeah, so the whole idea is we want to catch people when they're starting to drift down before they get they drift way down. So, there's a couple of different recommendations. I said, you can use the actual volume if you're so inclined. I said, I'm back to recommend that change that you follow the percent predicted and the basic what they say is if it's over 9%, it's a significant change. But they still recommend that we use 15% predicted to identify an important something you do something about change. The 9% in perfect spirometry is pretty okay, but to allow for imperfect spirometry, 15% gives a little more wiggle room. So we don't. Overreact to things that aren't that important. Does anybody use parole somebody ever use parole? It's in the room. Okay, so it's a role. It was a product that came out with the did that did this following spirometry over time. Super elegantly. I think the thing was written in 4, or something like that. It ran on a, you had to download it and run it on your own PC. It won't run under the modern. Operating systems, so you had to still be running Windows 98 or I don't know when does XP or something on your PC somehow to do it. You couldn't share between workstations and it wouldn't suck data out of your spirometry. You had to hand type all your data in. Essentially, nobody ever there was, there were like, 5 users in the country that ever used it and so they elected not to. Continue work on that project, so if you use parole, you can keep using it. It won't stop working. It just won't be updated anymore. Okay, so a little some cautions. 1 of the things we know is that in the 1st, couple episodes, spirometry people do worse in almost all the studies of serial spirometry. Um, they what they do is they just discarded the 1st, 3 spirometry episodes because they know people are learning how to do this weird test. Um, be cautious early in the work life, you know, where that knee is in the printed equations, because otherwise you can end up with like, really confusing things. I'll just just a reminder for how the 1 knee works. And it's a different ages, but if the, if you test the person, if I'm using Newton, 76, the purple at the bottom, and I test them at 212325, get a really different number and it's not because they're different. It's because the, the, they, they, they pass the knee and their particular equation. And as we're all aware, it's different. People reach true lung maturity. Different ages can be as long as long as but young is about 18 for guys and up to about 25 in that range. Um, it came out and it was available to us in January. Um, this is the big version of the, of the summary chart. I'm just going to do the summaries because this is the details are, are going to become confusing. So, um, the, the basic. Different things you'll notice is the reference equations. So, they, they, they strongly encourage the use of race or ethnic equations over adjustment factors. So, you know, black is 85% of white or Asian is whatever percentage are recommended strongly against using those. In the US, they still recommend NHANES as a reference equation. In Europe, they're agnostic. Interestingly, they're not recommending any lung volume or DLCO. Equations, which is kind of interesting. That's about halfway down the page. And I'm sorry, and as we move across, they're now recommending I did that wrong. So they're recommending, we used to recommend in the US use NHANES, Europe, whichever we want. Now, they're going to everybody use GLI. Clarify and they're, they're trying to make the point that clarifying the. Biological sex, not gender is to be used to interpret spirometry. We'll talk more about that in about. Half an hour, and then they, they're still recommending the 5th percentile normal, never ever using the fixed ratio of 0.7. That's a, that's, that's in their stamp. Their recommendation has before all that. So the gold criteria, they agree should not be used for diagnosing anything. something called a conditional change score in children. I'm going to skip that because I don't understand it. They recommend FEV1Q in adults to follow them or change over time. Has anybody ever used FEV1Q? This is an interesting concept, and all we're going to do is we're going to take the lowest possible value, the 1 percentile number for somebody like you, and all we do is male and female. So males are 0.5, females are 0.4 liters, and then we just say what multiple of that are you of that. So if you blew out 5 liters, 5 liters over 0.5 would be an FEV1Q of 10. I don't—we're still learning. I don't know if that's useful, but that's actually the intent of the recommendation. Just to make my brain hurt again, there's no—they never define FEV1Q anywhere in this paper except in the recommendation to use it, which is kind of frustrating. In FEV1Q, it's a concept that they're trying—again, it's a question about racial correction. Maybe that's going to be part of it. I'm not sure. And then for all measures, they talk about severity. This is where I'm coming back to the question I was asked about using Z-scores. So we talked about severity. They want us to use the Z-scores for severity separately for FEV1 and for FVC. So mild is 1.65 to 2.5, moderate, minus 2.5 to minus 4, and if it's worse than minus 4, that would be severe. That's the current recommendation. The thing I really dislike about this is I don't know what it means to the patient. Let's say you've got somebody that's got severe restrictive disease, but their ratio is normal, right? They just got horrible. So I'm going to tell somebody that the severity of their lung disease is severe normal or severe mild, which just— and if it's severe, severe, I kind of get that, but if they're different, I don't know what it means. So I just want us to be careful as we start thinking about this. I like—the one thing I did like that we had FEV1 was always what was used to do severity, even if we—we may have looked at other numbers, but the severity always came from FEV1, so any particular test had one severity. I think that's a safe—I like that better. I think it's more understandable by the patients. They talked about airflow obstruction, kind of the same thing. Restriction, the total lung capacity has to be less than the fifth percentile. That's new, and that requires that we have total lung capacity normals that have well-calculated, statistically-based lower limits of normal, which the older ones do not, and they also allow for the concept of hyperinflation. Okay, so let's—where do I go here? So this is how they're describing obstruction and restriction in this paper. This paper is actually outside the paywall. You can look at this. If you do this kind of work, you can look the paper up and read it on your own. It's not super long, and they just—they've defined their definition of obstruction, restriction, and mixed, and here is kind of the graphic version of that. One of the things they're allowing for—they're starting to talk about the concept of an upper limit of normal, which does make sense. Funny thing is, where I want that is in residual volume because that's the one where if it's—the bad is if it's abnormally high. I want an upper limit of normal there. I don't really care what the upper limit of normal is for FVC because, remember, there's still going to be 5 percent of people beyond that, but they are allowing for that concept. They're also allowing me to have people with large lungs. Large lungs is now a diagnosis, and now they're the people that'll win some aerobic thing at the Olympics, and that's okay. I mean, it's mutants that win at the Olympics. And so, they're allowing that that's not necessarily a failed test because they used to say that if you had over 130 or, in some cases, 140 percent predicted, it was just—the test was wrong, and it was unreliable. So, more about the Z-score. This kind of shows it kind of graphed in there, and you'll see the mild, moderate, severe defined, and then it has them—for each measurement, you kind of see them across the bottom, the mild, the moderate, and the severe in the different color brackets. What they did was they looked at the severity of impairment, and if you use the FEV1 for severity, this shows how for—you're going to call, like, an 80-year-old female is going to be called mild when they're above the lower limit of normal. If you use the Z-scores now, that forces me to put mild where it's supposed to be moderate and very severe. And you can see how it was grading people with the same spirometry differently based upon their age as what was mild, moderate, and severe. That's why they're recommending we use the Z-score for doing severity. I wish they'd said, just use FEV1 severity, and I'd be okay with it. I dislike having them separate. So, a little bit of conclusions. What they really want in the new—and this is—it's a progression. In 2005, they said, do spirometry this way. This is how you interpret it. Write down the results and be quiet. And what they've been progressing towards is, let's not have, like, super strict cutoffs. Be a doctor. Look at the results. Let them inform your clinical care, and don't obsess over individual numbers. That's really the progression we're going to. That we don't—you know, if they're close, you know, just like you would do with another—you know, with a CBC or with a liver function test. It's—you know, if their AST is 41, you're not going to get super excited. If their AST is 7,000, you get excited, right? And this is—and they want you to use the same approach to spirometry. It's not a—you look at the chart, you fill—you write down the words from the chart, and you don't have to think about it. That's not where spirometry should be. Any questions about spirometry in general? From purely clinical, you're not seeing anyone go through this when they're doing their spirometry testing. So hopefully, you've worked with your tests and things. But say someone came in, they admitted to having a cold, they do the spirometry anyways, and it's off or it isn't. How do you let them redo that? And what is that one? An outlier, as far as just consistency with the quality of the test? So the way that it works in my clinics is the federal government has sent them there that day to have a test, and we're going to do their test that day. If they have a cold or something, we may document that. That becomes really important if you're doing serial spirometry. But for me, it's whatever they did that day is what they did that day. And the text will document, you know, they were coughing or they were pre-production or whatever. I'm ready for my next talk. Probably over ready. I'm sorry. If there's anybody with questions, Jeffrey, we'll set you free in just one second.

spirometry

occupational medicine

lung function

interpretation

GOLD criteria

COPD diagnosis

GLI standards

z-scores

NHANES

predicted value equations

patient outcomes