this webcast and any accompanying materials are copyrighted by the American Association for Respiratory Care any public display sale copy or distribution of the video or materials may only be undertaken with the prior written consent of the aarc copyright 2013 All Rights Reserved my name is Shauna Strickland I am the associate executive director director for education at the aarc I welcome you to today's presentation pulmonary function testing Respiratory Care Journal highlights upon completion of this aarc webcast participants will be able to discuss at least one quality issue related to selecting Personnel to work in a pulmonary function lab identify at least one clinical indication for measuring lung volumes describe a bronchial challenge test that uses an indirect agent suggest why using the lln may be preferable to using percent predicted and name a new method for COPD screening I am pleased to welcome Greg ruple Mr ruple is an Adjunct professor in the pulmonary critical care and sleep medicine division of the St Louis University School of Medicine and is currently the chairman of the nbrc pulmonary function examination committee he is also co-chair of the Respiratory Care Journal conference proceedings Greg discloses that he has relationships with medical Graphics Gilead Sciences and biomedical systems Greg welcome to the program well thank you shaa and thank you for having such a large group of interested folks uh showing up here this afternoon greig I'm not sure if you can hear me or not but it s looks like we lost your audio there well everyone stay with us for just a second while we get that microphone back to Greg I'm sorry there it is that better thank you okay so the uh this is information that was um presented at the pulmonary function Conference held back in March of 2011 and then published earlier uh last year in uh the journal um and so I'll try to hi Greg it looks like it went out again on us okay every time I change the slide it seems to go out um the question here is what are these guys doing and those of you work in pulmonary Diagnostics probably recognize uh that this is myself and Dr Paul enri demonstrating the MIP and me maneuver um otherwise known as suck and blow and so uh we had a good time at this conference and um I'll continue on and let me know if my voice Fades out again the um conference participants are listed here Paul and I were the um co-chairs of this and as you can see there's a uh quite a a knowledgeable panel of individuals uh who are involved in the conference itself um and I will basically touch upon the um topics that each one of these individuals addressed and of course there's no way to cover um the entirety of of what was discussed in each of their one-hour presentations but I'll try to highlight uh those uh parts of the presentation uh which are uh most um appropriate for the topics that we're interested in here today uh when we set up the conference we um thought that it would be better rather than just reviewing the state-of-the-art in pulmonary function testing to actually look at some problems um or questions that uh should be addressed in bip pulmonary Diagnostics and so you see here a list of the 13 questions that were provided to the presenters um and they are I'll just read these off attacking the endemic of dlco errors in the PFT lab any what is the clinical value of lung volume measurements what's the best PFT for wheezing patients with normal spirometry which pfts best differentiate between COPD phenotypes uh children should not be treated like little adults in the PFT lab what's the role of pfts to monitor the adverse effects of things like surgery drug treatments and radiation uh Airway resistance what's it good for uh when should exercise testing be done would you like your mother tested by this technician and what uh is the appropriate interpretive strategies to optimize classification how should the lower limits of normal uh of the range be defined and should we keep pushing for a spomer in every doctor's office and what might the PFT Lab look like in the future as I said the um those are the questions that we gave the participants and when we look back over the topics and how they were discussed there were really four major themes that popped up and those were tests and testing quality issues uh the use of predicted values and then interpretation of pulmonary function tests and so there was quite a bit of overlap in the presentation so as I go through each of the individuals topics um I'll try to uh show you where those overlaps are heard Dr Meredith mcari talked about um the fact that diffusion capacity testing even though it's been standardized more or less for the last 20 years or so um still is much more variable uh than most clinicians would like and the main uh components of her presentation is that quality control for dlco testing isn't done routinely equipment technologist are still the sources of variability when we compare dlco measurements done in different labs and finally that uh the repeatability criteria that we currently use may actually be too lenient uh for most purposes Dr mcari showed some uh unpublished data from Jensen at all um showing um a group of 125 PFT labs in which about a fourth of them failed uh simulator testing uh when they were being evaluated for a multicenter trial that included dlco uh the good news was uh as you can see in the slide presented here is that U by cleaning up some of the problems that were involved in some Labs um the number of failed simulation test dropped to much less than 10% um over the course of this particular uh investigation so it it's apparent that uh applying uh careful quality control rules to things like dlco testing uh the the quality of the test can be improved over time um she also talked a little bit about data from her lab uh and again this was a um a study from a multi-center trial 33 sites were involved a large number of participants and what they showed is that uh you probably can't read the um the um xaxis here but where the arrow points to 95% that's showing that the uh repeatability of dlco efforts uh within the same patient in the single testing um was uh 95% of the time uh could be within 2 Ms of Co per minute per millimeter of mercury which is significantly better than the current guideline of 3 Ms per Co of co uh and they even showed that the um uh 75% of the participants could get within uh one mil of Co so again her suggestion was that we may be able to do a lot better than uh is currently being uh recommended by the atss guidelines I was given the topic of uh whether or not lung volumes are um useful and um the areas that I tried to touch on were that lung volumes are required when the vital capacity is low um that air trapping and hyperinflation do show response to Bronco dilators and that may be a reason for doing lung volume measurements and we also discussed briefly whether or not there's an ideal method for uh doing the measurements um whether or not body box and dilutional techniques can be used interchangeably or not uh a lot of the data that um was presented at the conference was rather old data but we felt it was important uh to um bring it up in the context of the types of questions that we are attempting to answer this is some data from Shan Aon and colleagues and they showed way back in 1999 that when the vital capacity was reduced and you can see that on the x-axis of these graphs that the probability of restriction went up dramatically um the other thing that that they uh showed was that uh a normal Fe that is an fvc up in the 80 to 100% of predicted range uh was uh very seldom uh associated with a restrictive problem so we know that a low vital capacity can be due to either um obstructive lung disease or restrictive lung disease but a normal force vital capacity really tells us a lot about the total lung capacity it's only when the fital capacity begins to fall that we need to consider whether or not we need to measure lung volumes and so the suggest question here is is that if the vital capacity is abnormal then lung volumes are likely indicated in the slide uh the graph on the right hand part of the slide simply shows uh that that's even more important uh when we take into account the fact that the individuals may have obstructive lung disease uh the lower um lines on that graph are folks who had various different degrees of obstruction another uh topic that I uh touched on briefly was the importance of lung volumes in assessing response to bronchodilators and this was some data that was fairly knew at the time from Dennis o Donald's lab in Canada where they looked at a large number of COPD patients and showed that um when they compared response to bronchodilators by uh gold stage um that things like uh that involved lung volumes showed larger uh changes than even the uh um and garden variety things that we normally think about measuring for brona response such as the F1 and the fvc and so you can see highlighted on the slide here in pink um are individuals who had a greater than a 10% change in their lung volumes or any other uh measurement and the part highlighted in uh Pink shows that the residual volume showed the greatest degree of change of any of the lung function variables uh list there and that the individuals with the U worst obstruction that is the um gold three and four group uh had the biggest change and so I think this is a good data supporting the fact that lung volumes may be uh as useful if not more useful for evaluating the response of bronchodilator than even the uh um the things that we normally measure such as the F1 so as you can see reduction in residual volume was really um the most uh predominant uh change that was observed in this large group of COPD patients the other variable that I touched on or the other topic that I touched on was whether or not gas solution or plethysmography U had any advantage and this was pretty much response to a paper published by odonnell and colleagues back in 2010 where they looked at the comparison between cosmography helium delution and CT scanning kind of as a tiebreaker and what they observed was that there were significant differences between those three methods uh especially when you compared plethysmography to CT scanning uh Unfortunately they concluded uh erroneously I believe that that uh plethysmography overestimated lung volume because of the comparison to CT scanning and helium delution and therefore um may not be uh the most appropriate way to measure lung volumes there were a flurry of letters back and forth after this paper was published and I think uh several other papers in the last two years have popped up in the literature showing that um this group of radiologist who thought that um plethysmography overestimated lung volume probably didn't take into account the fact that the CT measurements were done with the patient in the Supine position and in only one of the centers did they actually use spirometry to make sure patients were holding their breath at total lung capacity so the idea that the plethysmography is not the um gold standard um probably doesn't hold a lot of water and we probably need to um again consider uh plethysmography as as the gold standard when it comes to measuring lung volumes Dr uh Alan coats talked a little bit about Pediatric testing and the topics that he covered were coaching interpretation scaling of Graphics different variables and QC criteria uh for PFT that's done in pediatric Laboratories the uh I think it was interesting that he pointed out um some of the discrepancies that those of us who are normally involved with adult testing uh sometimes Overlook when we think about pediatric testing he uh made a point of uh showing us that the aging process which we know causes the loss of elastic tissue in the lungs and loss of lung recoil um really has not much of a a place in pediatric testing because uh lung elastic recoil is at its Max in P in in kids and therefore the kids have a higher fev1 fvc than adults and as such the fe1 itself uh may be uh inappropriate for measuring the status of the Airways and so he pointed out that even far back as the 1960s um feev values such as the fev 75 uh might be a more appropriate um uh thing to uh look at uh when we're concerned about U pediatric testing the he also pointed out um the much maligned FF 2575 which we know is quite variable uh in adults may have some uh usefulness in the pediatric population again because the Pediatric uh subjects tend to enter exit empty their lungs very rapidly and so that they completely exhale their Force vital capacity and we know that the FF 2575 is affected by the force vital capacity but the fact that uh it's much the vital capacity is much less variable in pediatric subjects um supports the idea that the FF 2575 uh may be a more useful uh parameter and so Dr coats um encouraged us to not um completely abandon it particularly uh in the Pediatric um population he also talked a little bit about um why the adult um uh quality guidelines may not be entirely appropriate for kids and uh he he simply showed us that the back extrapolated volume calculation which is done pretty much Auto atically by most of uh our systems uh may not be appropriate for kids simply because the um adult values when we talk about individuals with very small vital capacities uh may be entirely inappropriate so a child who has uh a vital capacity of 1 and a half liters um if we consider that 150 milliliters is a uh a reasonable amount for the back extrapolated volume that would be fully 10% of their their um their lung volume and so it's probably not appropriate uh to apply these same adult factors uh to Pediatric subjects uh again uh stressing the need for uh better um and more developed um guidelines for testing in pediatric Labs Dr David Kaminsky um uh addressed the topic of Airway resist distance and how it works u in conjunction with spirometry in the evaluation of individuals who have uh obstructive lung disease uh he uh concentrated on uh comparing and contrasting uh Airway resistance specific Airway conductance and specific Airway resistance all of which are used uh quite widely around the world for evaluating Bronco dilator and bronchial challenge resp responses and he spoke also briefly about some of the other techniques which are available um uh but are not widely used at least not in the US and those include forced oscillation and and interruptor type resistance devices uh which he felt uh were not quite ready for prime time but are uh quite useful uh in the uh U clinical research areas David pointed out for all of us that um the Airway uh conductance um is very sensitive to small increases in the central Airway um but not to small increases in the peripheral Airway and I think the top part of the slide here from Peter Macklin's paper back in 1983 uh is a good illustration of why that's the case because of the huge cross-sectional area of the small Airways uh that doesn't however mean that conductance um is not very useful simply because it's more sensitive to the uh bigger Airways um and as the bottom part of the slide here shows specific inductance is actually sensitive to the entire Airway and when the small Airways become heavily involved it too changes unlike the F1 which generally is felt to be sensitive to Airway narrowing Upstream uh of whatever part of the airway is actually limiting flow and we know that in individuals with obstructive Airway disease we see changes in both specific inductance and F1 but not always in the same proportions and so Dr kaminsky's contention was that these two tests of Airway function um measure different things and that they're L they are largely complementary not that we should be using one instead of the other he also he also uh pointed out the um uh information that was contained in a paper uh done in um some years ago uh showing that in patients who had bronchodilator studies um about 80 some percent of those individuals showed changes in the fev1 and fvc as we all uh have come to expect but that uh about 15% of the individuals who had a response to bronchodilator had that response not just in the um Airway resistance in the um spirometry measurements but in Airway resistance measurements as well and so things like the thoracic gas volume and isovolume flow curves um along with specific Airway conductance uh also can be very useful for assessing the response not only from um um yeah bronchial Bronco dilators but in bronchial challenges as well Dr Kaminsky also kind of summarized uh what he considered the important aspects of uh resistance measurements and again those are just highlighted in this uh graph that you see in or table that you see in front of you um spirometry that is the F1 is well standardized with a lot of good reference equations um whereas body pluses mography um uh is not so well standardized um but that both of them have fairly well uh established cut offs for Bronco dilator and Bronco constrictor response and that they uh do offer complimentary information when we're assessing patients who have Airway obstruction uh Dr Bon pachero from the Cleveland Clinic um tried to Enlighten us on when uh exercise testing is indicated and whether or not we should be using full cardiopulmonary exercise testing or just the six-minute walk test and his contention was that those two um things are not interchangeable there's still a lot of confusing confusion regarding which is the best test for determining Exercise capacity and even though this six-minute walk test has become very popular uh he held that it's not interchangeable with cped um the max oxygen consumption or Max fed out2 is still uh gold standard for most exercise testing uh and especially when for specialized indications like patients who are having thoracic uh reection heart transplantation Etc he also pointed out that there are a number of um parameters such as the ventilatory equivalent for CO2 and the heart rate recovery um parameter that are very useful for specific patients such as those with congestive heart failure he also um highlighted a few portable devices that may be um useful in the future uh when we begin to do exercise testing in a in a broader range of environments um he also pointed out something that I I consider fairly important and that is that the um measurement of uh oxygen saturation by pulse o symmetry has become extremely widespread so much so that we've um don't very often uh measure arterial oxygen saturation the way we used to many years ago and this is some data from the Cleveland Clinic um showing that um there are quite a few uh cases where um we get false positive um results when we compare uh pulse oxymetry and arterial oxygen saturation and a few um false negative cases as well as shown in the lower right hand quadrant of this this four quadrant diagram so uh he was uh um very um interested in the fact that uh we still uh place a lot of emphasis on pulse o symmetry in all different types of testing environments but that we need to be concerned about uh those false positives and false negatives when we're making diagnostic decisions based on the results of of Pula symmetry uh Jeff Haynes um talked about U um the technologist as an important part of the um uh testing regimen in most PFT labs and so he tried to take a little bit different approach and uh spoke to us about um how to select individuals to function as uh pulmonary diagnosticians and um to um uh look at some different ways of evaluating what might be important characteristics for people who are not just respiratory therapists but who are involved in pulmonary Diagnostics and so he showed us a number of different tools um that stressed things like motivation and feedback and how those uh those come into play uh in the individual who is working in the Diagnostic lab so this um this is just one of the tools that uh he showed that uh allows someone who might be considering hiring someone in a lab to evaluate not only their knowledge of pulmonary function and Pulmonary physiology but their motivation and their conscientiousness and some of the other important characteristics um that allow people to perform tests where the patient uh has to be encouraged to cooperate uh Jeff also uh shows some slides that uh indicated that the um way we normally think of hiring people into a particular job in the hospital um may not be the best possible way and he he showed us some data here supporting the fact that interviews job experience and even education may not as be may not be as predictive of quality uh on the job as as things like cognitive aptitude test that is the ability to do critical thinking and to learn when uh the individual is put into a new situation and so um he really kind of broadened out the um the scope of what we normally um think of in terms of um getting people into a pulmonary Diagnostics uh position uh by uh showing us that there were some other new and different ways of evaluating um candidates for these types of jobs I thought it was pretty interesting that he summarized by uh telling us that the traits that we should look for are things like cognitive aptitude conscientiousness um and critical thinking skills and so um he pretty much told us that the answer to the question would you like your mother tested by this particular technologist um can be uh addressed by making sure that the the people with the appropriate cognitive aptitude conscientiousness critical thinking skills are the ones that we have uh functioning in our Laboratories the other quality issue uh that was addressed during the course of the conference had to do with the use of spirometry um not so much in pulmonary function Labs but in in other venues in particularly in physicians's office and those of you who have looked through the literature in the last few years probably know that Dr Paul Enright has written a number of um editorials um suggesting that spirometry uh the gold standard for diagnosing obstructive lung disease um is is underutilized and that performing it in in Physicians offices although that seems to be a very uh valid idea may not work as well uh as we had once thought it would and his uh assumption was that respiratory therapists who are well trained and knowledgeable about spirometry probably have a uh a leg up on others uh in terms of providing access to good quality uh pre and post brona or spirometry particularly as it applies to diagnosing uh obstructive lung disease and he he shared some information uh this is data from a large Veterans Administration study showing just how often um U subjects or patients in the VA system uh got spherometer performed uh to confirm that they had COPD and the the numbers up there are some of the different VA um uh uh locations around the United States and you can see that the the best of those only about 45% of the patients uh got spomer and in in the worst of the quintiles uh only 23% got spirometry so it and there's other uh data in the literature that that supports this as well uh that tell us that you know spherometer even though it's the gold standard for diagnosing obstruction doesn't get used nearly as much uh as it should he also shared um some information um that's well documented in the literature also and that is that in spite of a lot of effort to uh Implement spomer in uh primary care practice and in Physician's office um many of these studies um spending millions of dollars to to attempt to do this that there are big differences uh in the spherometer that's be that would be done in in the general practitioners office versus what's done in a pulmonary function lab like most of you are familiar with in hospitals and so his um uh conclusion was to the to answer the question should we keep pushing for a spirometer in every doctor's office was was no and again I'm I'm simply stating that the was his opinion uh but he he offered some uh some rather unusual guidance uh uh to try to uh make this more realistic and that is things like don't refill uh COPD inhaler prescriptions without uh spherometer being used to confirm that they do have obstruction don't pay for poor quality spirometry tests and then uh he also wants far as to say it might be useful to provide Primary Care Providers with something even simpler than SP barometers uh or with pockets barometers so that they could uh look for individuals um who are at at risk for COPD and then um if th if those individuals could be identified that they could be then sent to a um a pulmanary function laboratory where good quality pre- and post bronka or spirometry uh was available so this is a little bit controversial but um I don't think it um uh should be anything that we're um hesitant to talk about um there have been a couple of papers published uh since our conference back in 2011 um showing the usefulness of things like Peak flow meters uh for doing a very gross type of screening uh in individuals who are at risk for um COPD and uh those were done uh by using Peak flow uh in conjunction with um the five question uh questionnaire that's widely used for screen individuals for risk factors uh was found that uh yes in fact you could um eliminate some folks who had um uh risk factors but didn't weren't actually candidates for spirometry and so even though the um uh data is just beginning to show up in the literature something as simple as a nomogram like the one you see uh provided here uh could be used um for something like Peak flow where uh if an individual who has risk factors for COPD uh blows into the peak flow meter and they fall in the green um shaded area regardless of their um age or uh gender um they would probably be unlikely to have a reduced fe1 whereas someone who uh had a peak flow that fell into the red portion of the nomogram uh could then be referred for um good quality pre- and post Bronco spherometer to confirm or refute the diagnosis of COPD so I think this is something to keep your eye out for um as we go forward um and we may see um um additional types of screen uh protocols developed in the future that give us a better handle on uh finding all of those individuals who we know have COPD but that haven't been uh correctly diagnosed or who have been classified somehow switching over to predicted and interpretation there were several um uh presenters who uh addressed these issues and so you'll see a couple of names listed here uh both Meredith MCC carick and Dr Al Miller uh talked about the fact that most of the reference equations for lung volumes and dlco um date back many many years uh and are not well established and that what we really need are enhan like standardization of predicted that would be useful and again uh that was uh something that the entire group um um concluded that uh is extremely important now whether or not that's going to happen uh within our lifetime I'm not terribly sure but the uh the need for uh more and better predicted for both lung volumes and dlco particular for dlco uh is is a much needed uh thing that that should be done going forward um and uh this is uh doubly true for uh the Pediatric uh population uh and for the elderly and again that was kind of consensus from Dr coats and Dr Miller the uh and this is just a list from the 1991 publication of the ATS show some of the widely used uh dlcl equations um and you can see the the most recent of these is 1990 so again um I wasn't being factious when I said most of these are more than 20 years old um there's been some uh a few papers published recently showing that the Miller um predicted the 1983 Miller predicted again this is the Dr Al Miller's um data that he U produced um do probably have the most uh wide ranging uh usefulness and there's been at least one paper showing that uh using those predicted uh for dlco um we're better able to uh correspond with individuals who uh have severe lung disease and were in in danger of U decreased survival because of their lung disease so um the the bottom line here is that the choice of DLC or reference equations makes a a difference and that we really do need um uh update of the uh predicted equations Dr Bruce Culver um went forward and talked a little bit about uh something that you probably have heard about and that is the lower limit of normal uh being used for determining whether or not disease is present and and Dr Culver uh made a point of emphasizing that um just because someone's pulmonary function variable Falls below the lower limit of normal U doesn't necessarily mean that they have disease so that it was kind of a two-pronged argument in that we need to use lower limits of normal rather than simple percents of predicted um because they they tend to be statistically more valid but we need to be careful that just because someone is at or near their lower limit of normal doesn't necessarily mean that they have disease and so again if you keep in mind that the lower limit of normal is really the lowest fifth percentile of a normal healthy individ of normal healthy individuals we simply assume that those uh folks that fall that far below the mean or the average um are significantly different uh but again they're really false positives they're really normal healthy folks that that have a uh a value that's that's well below the mean uh Dr Culver also um showed us some information uh from the global lungs initiative which he was involved in and I'll show you another slide here in just a moment with some of that information and he talked a bit about um using what's referred to in statistics as the LMS modeling approach uh as a better way to uh come up with the predicted values uh that we all need in the pulmonary function land the LMS approach um was uh popularized a few years back by SAS oich and Janet stocks and their co-workers um in in Great Britain and what they did is they took this statistical method uh LMS standing for Lambda mu Sigma um which included not only the the typical variables that are used to generate regression equations for calculating predicted but also took things like the coeffic of variation and how skewed the data was and these are the this is this the statistical method that's widely used for growth charts in children and they applied it to the nanes 3 data um and showed that by applying this statistical method they could eliminate the the need for separate equations for children adolescents and adults and come up with a smooth curve that um could be used to describe the changes in lung function that occurred across all ages and so this particular method generates what we now refer to as all age uh predicted uh and uh has been used in in a much larger study and so Dr Culver um showed us some information and this is um was unpublished at the time but has recently been published in the European respiratory Journal just a few months ago and this is the global lungs initiative predicted set now this is just for spirometry and the graph that you see in front of you shows the fe1 again across all ages for a large number of different ethnic groups Caucasians African-Americans and orientals uh this is a an older uh graph that was uh published early on and the Oriental uh lines have now been subdivided further so that we have uh Northern Asian and Southern Asian groups uh that can be used uh widely and this data is based on um a large number of sub objects about 72,000 uh spirometries done in all these different ethnic groups from a large number of um studies around the world and you should be uh prepared to uh think about um utilizing the ERS Global lungs initiative predicted values uh for uh your equipment in your lab um not necessarily right away but sometime uh in the near future again uh several different individuals talked about uh the fact that our interpretive strategy such as the one that's promulgated by the American thoracic Society is probably a little bit too simplistic for for really uh stringent use in the pulmonary function lab and Dr Steve salsman uh spent some time uh trying to uh illuminate the fact that Bronco responsiveness um is not as useful as we once thought uh simply because it's not well standardized um and may show uh changes in the same subjects when it's repeated over and over again uh you may recognize this uh graph as the uh interpretive algorithm that was published in 2005 by the atss committee um you should note that all of the variables up there uh don't use percent of predicted but they do use the lower limit of normal um but as Dr Al Miller pointed out um the number of buckets at the bottom there are are probably not uh uh enough to really help us make U the types of diagnostic decisions or diagnostic clinical decisions uh that should be part and parcel of the data coming out of the pulmonary function lab so again um this is a a start in One Direction um by using the vital capacity and then lung volumes and then dlco to try to come up with um a diagnosis um but the group agreed that this could be refined uh probably a lot more particularly in those individuals um that have a low dlco um it's probably not um uh illustrative enough of the types of disorders that we commonly run into so although this is a good starting point uh it's not the end of the story Dr Bill busy and Dr salsman um also talked a little bit about cluster analysis and I'll show an example of that here in a moment but Dr busy um his topic was what's the best test for uh somebody with who's wheezing but has normal spirometry and so he basically addressed the whole idea of uh what type of Bronco challenge study um should be used and is there a way to help us decide what might be most appropriate uh for the patients that show up in our laboratory one of the slides that really caught my attention was the one that you see before you here uh and again this is one from Dr Bill busy uh and I think I think it's an interesting slide because I think he's really put together the physiology and and what we know about Airway hyperresponsiveness we know that ahr or Airway hyperresponsiveness is the key finding in asthma but we know that there's a whole broad range of how that presents itself and Dr busy uh pointed out uh or at least uh uh categorized um two different types of Airway H hyper responsiveness variable and persistent and his feeling and I think this is probably um an appropriate uh way to look at these things was that the variable aspect of Airway hyperresponsiveness was largely uh due to the things that you see at the upper part of the slides things like inflammation whether caused by an infection or an allergen or something that the subject gets exposed to in their environment but that that type of um Airway hyper responsiveness is variable the other side of the coin would be what you see at the bottom of the slide um which he could called persistent changes in the airway things like subendothelial thickening uh smooth muscle hypertrophy changes in The Matrix of the uh Airway wall itself uh that includes vascular changes as well all of those things that we sometimes lump together as Airway Remodeling and his uh way of looking at this was that this is the uh persistent part of um changes in the airway what makes this kind of come together is that he suggested that the variable component was more um likely to be uncovered by using an indirect type of Broncho challenge whereas the persistent uh components were more likely to be uncovered uh using a direct type of Challenge and he present sented some data from Dr s Dr Sandra Anderson to kind of illustrate um whether or not we might want to use something like methine versus manitol uh manitol being an indirect type of Challenge and methine being the classical direct type of Challenge and this is some data in individuals who had a number of different tests done including both manol and molan challenge as well as exercise testing and I think you can tell simply by looking at the quadrants and in this diagram that the uh there's a quite a bit of scatter um there is a a weak relationship as pointed out by the r of 0.41 um between individuals who have a change in their Airway function when they're exposed to methine versus being exposed to manitol um but um again the blue dots represent individuals who had a little or no response to exercise versus IND indviduals who had a uh a pronounced response to exercise and you can see that um whether you use meth Coline or manitol um you may pick up one or the other what Dr busy was uh careful to point out was this variability suggests that perhaps the way we need to think about diagnosing what's causing the airway hyperresponsiveness is to be prepared to use more than one uh challenge agent maybe exercise or manitol in some instances versus methol in in other instances and so he went on to provide us with some information from Donald cock's lab where um cockro compared the direct and indirect uh types of challenges and what he uh kind of shows in the table here is that the direct challenges really do um work to tell us about the muscle function Airway caliber but the indirect challenges really have their um High Point in in pointing out who has inflammation so again the type of dose that's needed whether there's a dose limiting effect and then the sensitivity and specificity um is significantly different between the two types of challenges so I think most of this can be summarized fairly well simply by looking at the bottom line there uh we can think in in diagnostic terms of the direct challenge again something like methine being used to rule out Airway hyper responsiveness whereas the indirect challenges exercise hypertonic sailing manitol those types of things might be better uh used to rule in um the type of Airway hyperresponsiveness that we associate with exercise induced bronchospasm and again um this is some data that Dr busy showed us simply showing how cluster analysis can be used to show that uh the various phenotypes that show up in individuals with asthma um can be uh pretty well um segregated uh when we apply the types of uh analyses that's shown here and so um this is a large ongoing study U that Dr bus's Labs involved in and you can see that in addition to the demographic information at the uh top um we have the typical Baseline lung function and then maximal lung function uh after bronchodilator along with atopy determined via skin test and you can see that across those clusters of different um degrees of Airway obstruction and responsiveness um there's pretty significant differences in fact the differences are significant in all of the categories uh save um uh race um I'm sorry except for body mass index and so uh I think this is the type of uh analysis that uh is useful uh and will probably stand Us in good stead as we um look to the Future in terms of what pulmonary Diagnostics can offer um there were quite a few things that the group discussed um and one of the things that uh came out uh in multiple different presentations was that the preest probability of disease is important and Dr Miller pointed out that this is something that the pulmonary function lab uh should be responsible for in other words the history and physical findings that we record in the patient at the time they're being tested um are very important and that's something that that should be included as part of the report uh to the individual trying to interpret the numbers Dr hanuk um spent a bit of time talking about the role of pfts in decision making um and he this was basically a review of uh when pulmonary function tests um are indicated and when there are situations where they may not be indicated and so we know that if you're patients being worked up for thoracic surgery particularly for lung resection the pulmonary function tests um are a a a very important part of that however poor lung function um is probably not a contraindication for other types of surgery and I think this is has come to the four um in the last few months if you if you've been paying attention to the local news you may have heard them talk about the um American Board of internal medicines initiative choosing wisely where a lot of different professional physician groups have come out with uh the types of tests that aren't necessary uh for different types of proced procedures and again uh one of those recommendations includes things like uh were discussed here what's important for um making therapeutic decisions and what things are not important so I think we're going to see more of this type of uh information in relationship to the types of tests that we do in the pulmonary function lab now and in the immediate future again um further study of the patterns of pulmonary function are needed if there was one overreaching topic that came out of the uh conference this was it that um we need to be able to relate physiologic findings to outcomes um and that something that um falls on not only the physician interpreter but is part and parcel of the individuals performing the test as well is to be able to make sure that the physiologic data can somehow be related to outcomes and that probably has its most uh important uh implementation in things like setting severity thresholds you probably are aware that the severity thresholds that we have for COPD are arbitrary they haven't ever been validated so we we say that someone whose fev1 is less than 50% of predicted has severe COPD but again that's a an arbitrary number that that needs validation and that's one of the things that pulmonary function testing um can provide so the group felt that um evidence-based uh medicine will benefit from uh providing physiologic data that can be related to outcomes last but not least uh Dr Neil McIntyre spent a a bit of time um sh talking about what he uh considered uh things to watch for in the future and again there was quite a bit of overlap with some of the other presentations um but the thing that Dr Mcintyre stressed for most of his presentation is that more and better training for both technologists and Physicians um will probably be the thing uh that makes pulmonary function Labs um important and necessary U for the foreseeable future uh he also reiterated the fact that um we need to do a better job in terms of making sure that the data that's produced in our Labs that uh is good data and that comes through good quality assurance and that was really something that the entire group uh stressed he also talked a little bit about some of the newer technologies that that might be uh something to watch for in the future and that included things like uh exhale gases that can be used to look for neoplasms in the lung uh uh condensates that can be used to look for um specific types of pulmonary function abnormalities and as I have already mentioned that pretty much crossed the uh Spectrum in terms of individuals uh touching on those things the the the entire group thought that there was a definite need for better application of sporet and even though spirometry has been the uh the wherewithal of the pulmonary function lab for the last couple of hundred years um we can do a better job of making sure that it's used appropriately uh and that it will be important in the future um all of these uh papers were published in the January 2012 issue of Respiratory Care and I would encourage you to make use of the online availability of these papers uh if any of these particular topics um uh caused you to have a question or um are related to things that uh are partent to your uh day-to-day operations of your laboratory uh you can find them uh the complete papers in this particular issue of the journal and I would encourage you to um go and find the the paper that meets your needs uh the references uh are very uh good for all of these papers and the the journal includes the discussion that went on among the participants and in many cases this was a quite Lively discussion and there's probably as much to be learn from the uh participants discussing some of these topics as there was from the uh present presentations themselves so I'm going to stop at this point and um if there are questions uh we have time I'd be happy to try and answer those Greg thank you so much this was fantastic and there's been an amazing amount of discussion um what I'd like to ask you to do Greg is to hang on for just a second I'm going to end this and then as the survey is up have um have you answer some questions as there are some folks who need to uh scoot out of here uh due to time so so um if you're are watching this as a live presentation please stay with us for a second um for instructions on how to obtain your crce if you're watching this program as an archive this concludes our presentation