I think a more appropriate title for it would be getting in sync with your patients. So it's trying to think about some of those synchrony settings and how to and how to get in sync. So again I'm Dr. Aaron St. Laurent. I'm coming from Western University in London, Ontario. So that's the Children's Hospital London Health Science Centre. I have no disclosures to make. So I'm gonna start by quickly kind of covering a little bit of an approach to a PAP or a non-invasive PAP download interpretation, cover a differential for non-adherence, and then again think about some of these comfort or synchrony settings when and how to adjust them. There are a couple of good papers already that look at or provide approaches to PAP interpretation. So I use these in the course of my presentation and just wanted to kind of point them out. One of them is by Philip Choi, Veronic Adam, and David Slinsky. Unfortunately Philip is actually presenting a talk right now in another room. And then this is one from a pediatric group at SickKids. So Dr. Prem and Dr. Reshma Amin. But it's a very, you know, similar approaches. For myself I'm a simple person so I don't love mnemonics but I find this one useful. So when I look at a download the first thing I want to look at are the settings and the download window. So I make sure that they're on the settings I expect and the time frame is one that I'm expecting. I usually recommend a 30-day download window. And then I look at the actual adherence, so how it's being used and are there usage patterns, especially as a pediatric provider, but really anyone who has caregivers. Sometimes it's caregiver related when you have issues with adherence or support. Next you look at leak because big leak leads to big problems. And then finally am I delivering effective therapy? And depending on what the indication is for starting your non-invasive ventilation, that could be related to your AHI, that could be related to tidal volumes, things like that. And so to kind of think through this topic I'm gonna cover, we're gonna, I'm gonna present one case but we're gonna, it's gonna keep coming up throughout the presentation. So this is an 11 year old girl of Syrian descent with an RYR1 congenital myopathy. So I had recently started practice when I met her and you can, and I was actually surprised she wasn't on bi-level pap already. She had severe scoliosis, she had significantly reduced vital capacity with an FVC of 22%. The family was reticent to start technology and so I organized a polysomnogram which showed REM disorder, sleep disorder, breathing, and nocturnal hypoventilation. So you know given all of these factors the decision was made to progress and initiate bi-level pap therapy. This was a socially complex situation though. The family were non-english-speaking and there were five other children's in the home. They were dependent on income assistance. There was only one parent capable of driving and the father who that was also was working and the family lived two hours away. So a lot of factors leading to a complicated NIV start. She was admitted for initiation of NIV and you know she's a quite an anxious patient. So it was a very challenging start. She had a lot of discomfort with the interface and the setup and and just a lot of fear around it despite you using child life and acclimatization strategies. When it was on her, especially during sleep, significant mouth leak was noted and but she absolutely and adamantly refused an oronasal mask or a chin strap. Ultimately she was able to tolerate a start but definitely on suboptimal pressures. So again this is only a one night download from her inpatient stay. She's on on settings of 9 over 5 at a rate of 20. Her rise and fall are both 200. Her TI min is 0.8. Her TI max is 1.0. Her trigger is high and her cycle is median and she is on a Stellar device which I know you don't very often use in the States but it's a device we use in Canada a lot to deliver our NIV and it's pretty similar to other bi-level PAP devices from ResMed. So similar to the air curve. You know and from this download you can see the leak is obviously an issue. The median leak is 27 and the 95th percentile is 36 but again this was the starting point and the plan was to titrate her upwards later and actually you know she went home. It was used a little bit. She came back for her scoliosis surgery and we were able to titrate her up on therapy and in hospital she actually tolerated it quite well. She went up to you know but despite this adherence at home remained a significant issue. So we were able to titrate her up to settings of 16 on 6 at a rate of 15 similar TI to before 0.8 to 1.0 trigger high cycle medium but when you look at her adherence so going down to the next part of my mnemonic obviously it's not great. It's only being applied half the time and of that only four of the 15 days were she able to wear it for longer than four hours and the median usage is two hours and 35 minutes. So you know just kind of looking at the the whole download adherence isn't good. Our leak remains high so the median leak is is better than it was initially at 12 and the 95th percentile is just less than 24 and so if we look at kind of the algorithm from one of these papers this is the one from Philip Choi. Again the first thing you look at on the download is do you have the compliance you want and again he they recommend using greater than four hours but I think it's important to consider the indication for starting right. If this is a patient in my world with something like congenital central hypoventilation syndrome four hours is absolutely insufficient. If you're if this is an OSA patient who needs BiPAP greater than four hours might absolutely be sufficient but so do you get the compliance you want and if the answer is no well the first thing you look at is leak and so you know we saw already that she had high leak. The things you try to do is you try to properly size the mask you may switch the interface so if they're on a nasal interface you may switch to an oronasal interface you may use a chin strap or again if it isn't mouth leak and you think it's it's leak around the mask it may just be a different nasal interface a different size is what's required. This is a useful box so I'll hold it up there just so you can take a picture but just for the sake of time I'm gonna gonna press on and not go through every every issue. So again when you're thinking about leak it's important to know what device you're using. So I'm gonna talk specifically about ResMed and Respironix again coming from Canada we don't have access to the Vivo or the Louisa or some of these new devices but make sure with whatever that patient is using you're familiar with with how the leak is provided. So a ResMed device provides your unintentional leak so you have need to make sure that it's that your your mask is properly dialed in and so you know they recommend targets of less than 10 or less than 24 for the 95th percentile and you need to ensure that there's comfort that the patient has because what the patient feels even though it may be acceptable according to the company higher leaks mean higher flow and may not be comfortable. Respironix on the other hand uses total leak and so that's intentional and unintentional and that'll vary with pressure and interface and I'm sorry I'm gonna be racing from here on out. So if the leak is great but a leak greater than 60 liters per minute is going to impact your titrating algorithms. Another useful slide just to get a sense of what's accurate and what's less accurate. So things that the machine actually provides and records like usage are very accurate. When you're talking about title volume it's calculated and it's really going to be heavily impacted by leak. So things like unintentional leak and title volumes especially as your leak goes up these become less accurate. So if we look at our patient we attempted a climatization with those other interfaces but it didn't work. Still complaining about too much air or the air being too hot and too moist we you know we tried other interfaces and it was absolutely refused. So I've gone down on the pressure as you can see she still went down to 13 on 5 but really adherence was still suboptimal. So the next thing you do is you need to assess I said you know what we failed with leak but let's go down that algorithm and look at the next thing which is asynchrony. And so speaking to your patient may help you get a sense of where the asynchrony is occurring. And she kept talking about too much air and that's similar to this comment from this paper by Hanson Flachin and Jason Akravo where they talk about you know if there's too much if a patient comments on too much air at the start of the breath you might want to think about the rise time. And so the rise is the amount of time it takes to go from your EPAP to your IPAP. If you're using a ResMed device you actually dial in the time. Respironics is going to be a relative with one being a short rise and six being a high rise. Shorter rises are useful if you're if the patient is air hungry or it may facilitate speech on the ventilator. Longer rise times again if you get this feeling of too much air it's not being delivered fast enough or sorry or if it's being delivered too fast and if you get aerophage or secretions you may want to lengthen that rise time. The other thing I noticed on this download is actually our I to E ratio is about one to two point four five which again physiologically normally think about is one to two and actually in a patient like this even shortening it may make more sense. So when you think about adjusting your eye times it's going to vary with age. In our young babies it may be as low as point six. In adults and depending on the disease process you may be using rise times or sorry inspiratory times as long as two seconds. So your TI min is there because it prevents premature cycling into expiration. So think about your patients with weakness. They may be able to trigger but they typically can't sustain a breath so this ensures that they get effective breaths delivered as long as you give them an adequate TI min. Your TI max prevents this sustained inspiration and this is specifically to help kind of long inspirations in the presence of air leak because if there's air leak the flow never reduces enough to cycle out of EPAP. So you know when you're adjusting your inspiratory times you want to consider the disease process. In a patient with weakness or restrictive lung disease it might actually be okay to approach an I to E ratio of one to one. That'll give enough time for emptying. Whereas if you have a patient with obstructive lung disease again as a pediatric practitioner I don't use NIV for COPD but I imagine that you want to preserve a one to two or maybe even lengthen that ratio. You know you want to consider as well the comfort of the patient. This comes from a paper by Sandos and Dr. McKim out of Ottawa you but basically they should they stated that in general higher pressures are less well tolerated and if you're trying to target volume and filling you can actually use I time to do that as well. And so this this box just shows the patient came to them. One of the big changes they made was they just increased the TI from 1.2 to 1.6. They didn't adjust the pressures and they actually backed off a little on the respiratory rate and when the patient on the download tidal volumes improved, minute ventilation improved, and the daytime and tidal CO2 in this patient with neuromuscular disease had dropped from 75 to 57. They did also change from an ST mode to a pressure control mode but that again is typically going to be an I time difference. So when you're optimizing your inspiratory time you need to think about what your median TI is relative to something like the TI max. If your median TI is the TI max you might want to increase your TI max if you're not getting the volumes you want or if the patient's breathing at a high rate they're telling you they want bigger breaths. Whereas you may want to decrease your TI max again or increase that psychosensitivity if you're already getting high volumes if you're not getting this high trigger rate. And in that case you also want to consider is there a large amount of unintentional leak because we keep hitting our TI max. If our median TI is typically the TI min you need to consider do we need to increase this TI min are we and that's going to be happening if you have a low tidal volume if you have a high rate again this patient is telling you I want bigger breaths I want I need better ventilation. Whereas if you're consistently hitting the TI min but your tidal volumes are high your TI min is probably set too high. Unfortunately again you need to think about what result you're trying to achieve when you're adjusting your TI. Okay so I made a number of changes to this patient we increased the rise time from 200 to 500 and I adjusted that TI. I apologize that I only have an 11-day download they had unplugged their modem and it only saves 10 days after that but you can see they went from a very poor adherence to now on those same pressures but with an increased rise time suddenly our our usage is much better so we're greater than four hours 91% of the time with a median usage of 11 hours and two minutes. And just I had one last thing so again we've finally gotten through the poor the poor compliance we had already talked a little bit about leak. Next you need to think this isn't just to show the impact of leak on a detailed download you can see for the first part of the night I don't know if you can see they don't show so if you look at the first part of the night the leak is quite low when the leak is low this patient is capable of triggering and our title volumes are good and then as you move to about 3 a.m. I want to say that leak gets really high suddenly this patient is no longer able to trigger as well your title volume and minute ventilation recordings are probably inaccurate it looks like they bought them out but the reality is is we're probably don't know what it's doing and so this is just useful to know about the impact of leak. I had hoped to talk about some triggering and cycling but I'll let the next speaker talk. So again if you want to assess synchrony and you're thinking about trigger and cycle the important things are speak to your patient you can use polysomnography and bedside examination to look at the synchrony itself to see what do the flow waveform look like and clinically is this patient synchronous and finally we're now moving into a world where some of the newer ventilators like the Trilogy Evo actually gives you those flow waveform that you can look at. Now the problem is is if you look at the top that's what you see initially you do need to dig through that to look for these to and pull in the more detailed views but to get a sense of what is actually happening what where can these dis synchronies occur and then you can use that to start to hopefully improve synchrony in your patient. So thank you very much for attending and don't forget to allow your consent. Thank you Aaron. You basically said half of the things that I had to say on the next presentation so we're gonna cut you off with time. All right so I already told you my name. I just want to say that my university is located in an indigenous land is named Treaty 6 and is the land of Métis and indigenous First Nations people and that makes us who we are today. I have nothing to disclose but I do want to acknowledge my team because it's really their shape their knowledge that has made me put this presentation together today. Pull out your phones. We're doing so so with time so I might actually just ask you to raise your hands. You guys ready? While you guys pull out that maybe I can share the learning objectives. I'll go back and I'll just talk. We're gonna review what is really true in terms of accuracy of PAP download data in pediatric patients and hopefully at the end I'm just gonna catch up with our own left and provide some recommendations about how to incorporate this data into the clinical practice. But first I have a case for you. Miss Jury is a five month old girl with coronal craniosynostosis and skeletal dysplasia. By the time I met her she had had four hospitalizations all of them due to severe bronchiolitis like picture requiring breathing support. In the last one however the viral panel was negative and she was noticed to have noisy breathing and frequent oxygen desaturation during the sleep. So ENT was called was consulted and inevitably the patient got a rigid bronchoscopy because that's what they like to do and they diagnosed severe bronchomalacia and some kind of unusual trachea. So they called pulmonary and inevitably we start the patient on nocturnal CPAP. This is Miss Jury and as you can see here her mask is attached with an adaptive head gear to her helmet for her craniosynostosis. So we do a little bit of crafting in our center. This is the overnight oximetry of CPAP F6 and as you can see between the red bars is her sleep time. She had multiple clusters of oxygen desaturations but all of them mostly above 90%. So we were kind of happy with that and sent her home. Got a download at 30 day mark and as you can see here in terms of performance the leak was okay. There was a little bit of variability but median and 95% that were within recommended parameters for ResMed devices. Her AHI was elevated and was all obstructive and when you look at the bottom of the download the red box indicate that the patient is using the therapy less than two hours, less than four hours. So we call the family in for a follow-up visit and they state that CPAP has been life-changing for them. Jury has a little bit of residual snoring on her CPAP but she's sleeping through the night. She has a more consolidated nap. She has less issues with secretions. She's more interactive and she's catching up on her milestones. So we were a little bit puzzled and here's the question I have for the group. Good news there's no right or wrong answers. Why don't I get the answers in here? Okay I'm gonna give you the answer so pay attention. Answer number one, I suspect the parents are not telling all the truth and I kindly inquired about barriers of adherence. Answer number two, download of information is not accurate so I just ignore it. Answer number three, I asked if there is a second home machine that might explain her limited adherence. Number fourth, I am worried about her AHA and I immediately asked for a PSC. Or number four, I have a different approach at this situation and I'm gonna share it at the end of this session. All right 25 votes that's pretty good. Hopefully it doesn't take too much longer. Do I get to decide when to go next? All right okay so we have a little bit of diversity but basically people have other suggestions which I'm very happy to to know. I will hear about them later. Coming back to the first objective, when I first started preparing this presentation I went back to our representatives for ResMed and Respironix in Canada and I asked them whether there is any new information related to this topic and they kindly referred me to the manufacturing guide. So I built this table based on the recommended weight for most of the ResMed Respironix machines and as you can see here for CPAP machines we're around 30 kilograms of recommended weight. Bi-level ranges between 10 and 20 except for IVAPs modes and then really we need to go to a ResMed Astral or a Respironix Trilogy for recommended weight is below 5 kilograms. I could have stopped the presentation here but I do have a bit more information that I want to share with you and I'm going to use the ResMed manufacturing guide to share that information. So as Aron was saying before it is important to distinguish what is measured versus what is calculated by the device. All the devices have a pneumotachograph and a pressure sensor that the only thing they measure is pressure at the mass level and flow generated by the machine. So the middle column refers to the minimum change in the parameter that the devices are able to pick up and the right column refers to the variability or the standard deviation of that measure. So as you can see here devices do pretty good in terms of pressure like they're able to pick up 0.5 centimeters of pressure differences and pretty good with flows. They can pick up within 10% of what they're able to generate with a little bit of office standard deviation. You might have noticed an asterisk in here however that warns the reader that the accuracy might be reduced in the presence of leak, oxygen therapy, get ready that affects pediatric patients, low tidal volumes below 100 mils and minutes ventilation under three liters per minute which is really where the limitation is for pediatric patients. Now that I would imagine also affects to other patients who are very tachypneic weak and have low tidal volumes. I would like to also point out that the generated flow is very different than the patient generated flow for triggering purposes and the devices are usually pretty good at picking up flows that are as low as 2.4 liters per minute. Everything else in a download is calculated is not measured by the device and that matters especially for tidal volumes and minute ventilation as well as leak because the accuracy is less than for the measure parameters. We're talking about 20% within the 20% of what they're producing and the lower the tidal volume the more the variability which is another limiting factor in pediatrics. In terms of the patient trigger respiratory rate the devices are accurate but keep in mind that every breath that is not able to trigger the device and therefore doesn't provide support is also not measured and will not show in your download. So you need to assess that synchrony and trigger capacity asking the patient. What about adherence? I could not really find any mention to the accuracy of adherence data in the manufacturing guide or any articles that really assess that in an objective way but keep in mind that the way the devices measure adherence is by number of hours that the machine is on and pressure is detected. So if pressure is affected by low tidal volumes so adherence. In terms of PHI, Resmet and Respironis algorithms are very similar in terms of picking up reduction in flows that last for at least 10 seconds and it could be apneas or hypoapneas depending on the degree of the drop. I'm hoping that doesn't surprise anybody. Now there are a couple of red flags when it comes down to pediatric patients especially infants and very weak patients with high respiratory rates that can have clinically significant events that don't last for 10 seconds and therefore will not be reflected in the download. In contrast, software AHI are known for perhaps overscore AHI because they only use flow to determine if there is an event and there is no oxygen or arousal information to determine if hypoapnea is clinically significant. I'm going to show you a couple of papers on that. So Karyani in 2017 took 16 patients with OSA using Resmet devices within the intended use and compared the AHI on the Y inferred by the SIPA machine versus the polygraphy and you can see the AHI is consistently overscore. However, when they manually score following ASM criteria, the correlation was perfect. To me this suggests that the machines are really good at picking up flow, they just don't have extra information on oxygen and arousals to determine if the hypoapneas are important. In this other paper by Onofri, they took 90 downloads from Respironics and Resmet machines, all ages out of intended use included and when they saw similar study what they saw is that there is a group of patients that have an overestimated AHI by download and another group of patients that have an underestimated AHI by download and when they did multi regression analysis to look at the factors that affected that, they realized that preschool patients tend to have lower AHI, which again to me that suggests that perhaps there are events in there that are sure enough that the device is not able to pick up in younger patients. This is the summary of what I said so far. I really hope you enjoy my memory hungers. Calculated measurements might be unreliable and might have increased variability if there's large leaks, this is my favorite, supplemental oxygen or the tidal volumes are low or minute ventilations are low. Now I'm going to spend the last three seconds trying to incorporate this into the clinical practice and I'm going to refer to the same review papers that are on presented a minute ago, which makes my life much easier because I can go to final recommendations of what to do when we're out of intended use. Please be extra caution interpreting minute ventilation and tidal volumes, especially if you see there is high leak variability, differences between p5, p95, median P95, that's a red flag. Sometimes cycle-by-cycle raw data, as Arun showed us before, can give us more information and more level of understanding. I do recognize I struggle with this recommendation because it's time-consuming and it's hard to put it in practice, but it's definitely useful. When interpreting download AHI, if there are clinical concerns and the AHI is low, please look farther, especially if you have infants, tachycne patients, weak patients. They might require further PUC or inpatient admission depending on the setting of your center to be able to assess that those clinical concerns. In contrast, when there are no concerns and the AHI is high, perhaps looking at the trends of previous downloads might give you some clues of how significant those events are. And if you still worry about that high AHI, the use of overnight oximetry canography might also be useful to determine the clinical importance. This is my final recommendation. As it happened with my patient, it is important that we put PAP information in the clinical contents at the age of the patient. In our patient, the adherence, we believe, was very good. It was just not picked up by the machine, right? There are other many examples. My colleagues are going to go through some of them. But again, if there is a high AHI, it might be due to recurrent illness and not to the baseline breathing pattern of the patient. Or in patients with neuromuscular diseases, with large leak, it might actually be true. I mean, it might be due to mouth leak, as we saw before, and we actually have to act on. Thank you very much, and I'll be happy to share my slides. Thank you. I'll leave you with the real deal. Dr. Ashima Shani from the University of Chicago is going to talk about volumetric pressure support downloads. Aloha everyone, I hope you are enjoying and fully caffeinated. I'll try to be on time and go as soon as possible. So I'm from Chicago, still jet-lagged, but this is a good time because it's post-lunch. The sleep drives are better. I have no conflict of interest. My learning objectives are to understand the variables in our download and then troubleshoot based on that in our clinic setting. Just briefly, we are talking about WAPS, which is volume-assured pressure support. These are the two important manufacturers. There are newer devices that have come out. But I just want to refer to this diagram over here. You can see the tidal volumes is what the respironics, this is what the AWAPS does. It is going by the tidal volumes. Over here is your IVAPS, which is looking at your alveolar ventilation. So just remember those two important points. And when you're looking at your download interpretation, the most important thing is you do have to understand the WAPS is there in your RAD devices and your home vents. When you're looking at RAD devices, they don't have the AE mode that we talk about, the home ventilators will have that. That's the most important thing to remember. The other thing is when you're looking at the download, please make sure you know what the prescription is. I've had multiple cases that whatever you have put in doesn't get translated into clinical practice. So that will be the first important thing. You should know whether it's a RAD device, it's a home vent, and what your prescription was. The second, I would not dwell too much on it. We have gone over this, what are the directly reported variables and what are the calculated variables. So just keep that in mind. So the first thing is about the AWAPS, I'm showing you the first download. I just want to make sure everybody understands this. What is the circuit type? The passive circuit. So these are the circuit types that you'll see in non-invasive ventilation. The first one is showing an active circuit, and you have the expiratory and the inspiratory limb. You usually will use this for vented patients with trachs, but you can have it with a mask as well. The other two are your passive circuits. So over here you have your exhalation port, and over here is the vented mask in which you are doing the exhalation ports are taking care of that. So just to make sure everybody understands what the circuits are. So this patient had a passive circuit. The second important thing to look at is the mode. So it's a pressure control mode. This is an AWAPS patient that we are talking about. And these are briefly the modes I'm talking about in AWAPS. So you have the spontaneous mode, you have your ST mode, the pressure control, and then you have your VAPS. It doesn't really matter much now with Philips, especially the EVOs that have your TI min and max added to it. But this will matter for your RAD devices that still have the ST and the pressure control mode. So the important thing is the TI time that you set in an ST mode is not kicking in in the patient-triggered breaths. It will only kick in in your pressure control mode. So that's the important thing to remember about Philips. So this is about the pressure control mode. Then you look at the tidal volumes that has been set on. And now the AWAPS is on. So what is happening is you're having the machine will sense the tidal volume. It will try to achieve the pressure support to get that kind of a tidal volume. So it's an add-on feature to your mode in Trilogy at this point. So this is your astral download. So again, same things. Over here, this patient is on IWAPS auto-EPAP mode that I was talking about. So in ResMed devices, you don't really have ST and pressure control mode. Your TI min and max can determine that. If you want a patient to act like an ST mode from Philips, you just reduce your TI min. If you want it to act like a pressure control mode, you just increase your TI min. So it will kind of mimic the same thing. Over here, it's the same circuit that I talked about. So this is the passive circuit basically with the leak. And then the height is very important in IWAPS because that's how it is calculating your dead space and helping you with your alveolar ventilation. And I'll have some examples on figuring out how important the height is. I have had patients in which the height was inaccurately entered, their alveolar ventilation was messed up, their tidal volumes are low because of that. So please be very mindful that you have your right height. If your patient is wheelchair-bound, cannot stand up, you can have the wing arm span measured. If you cannot get an accurate height assessment. So just keep that in mind as well. In interest of time, I know the first two speakers have already talked about the sale, which is amazing. So you look at the usage, you look at the leaks, and just remember the intentional and the unintentional leak. So ResMed devices will always be reporting the unintentional leak. The Philips device records the total leak. So just remember your variables for that. And then again, the tidal volume is measured, so it's very important that the leaks are taken care of. And then we already spent some time on the AHI that gets reported on these. So it has a pretty decent sensitivity and specificity based on the articles that have been published. So I won't dwell too much about it. So this is the approach we already spoke about. So I won't take much time on this. So this is our first case. So patient with OHS is on AWAPS AE download, comes back for follow-up, and you are reviewing a download. My biggest concern was this. Why is the patient triggered bred down to 6%? This is an OHS patient. It's not a neuromuscular patient that I'm dealing about. So what you have to remember is, please, over here, I'm like, this is all the download. But the part I want to make sure you see is the breath rate was put on auto mode. So what that does in Philips devices, it takes the... So the software studies the patient in the evening, in the beginning, and targets that for the rest of the time. So by the end of the day, a patient who is huffing and puffing is pretty tachypneic, has rapid shallow breathing. And Philips, because of its algorithm, will start mimicking that for the rest of the night. So my caution to everybody is, if you are doing that, put it on a manual backup rate. Don't leave these patients on auto. You will not really encounter that in ResMed so much as compared to Philips. So in this patient, it's an OHS patient. There's no reason this patient should not be triggering your vent. You want the diaphragm to keep working in this patient. So taking away this auto backup rate will help you. So these are minor things, but they're important in the long run for these patients. The second important point, how do I set my target? So I'll talk about... So the target, basically, is either tidal volume or alveolar ventilation, based on what devices you're talking about. So in most cases, you have to keep it close to 8 cc per kg, with some exceptions, especially for patients who have scoliosis and ILD, you might want to target close to 6 cc. In OHS or spinal cord injury patients, you might want to target close to 10 cc. The important point that most of my fellows sometimes still fumble on is, it is the ideal body weight. Do not take it from the total body weight, please. That is very important. And when we talk about low tidal volumes, it is more in an ICU setting. It's more for acute lung injury in an ICU setting. There is some chances of it having issues long term, but 6 cc is usually restricted for scoliosis and ILD, as I just talked about. So how we do this in ResMed, this is an online calculator that if you just put IVAPs on it, it will show. You just put your height variables and you press all the buttons and you'll get the alveolar ventilation. I feel like if you give this to your DME, the chances of inaccuracy or issues will be less. So this is what you have to really see. This is a RADS device from ResMed, the STA device. I just want to show you that over here you can see the mode. And this is your alveolar ventilation and this is how you calculate that, okay. The next case, this is a patient on VAPs, AE mode. You have a target tidal volume of 7 cc. You have an EPAP min and max of 5-15, pressure support min and max of 5-10, with a backup rate of 18. And this is your TI min, it's .3 seconds and TI max of 2 seconds. The trigger is high and the cycle is high. So when you look at the download, the average IPAP is close to 15 and average EPAP is close to 5. The patient is profoundly tachypneic. So what do you do? Will you change it to a pressure control mode? Will you increase the tidal volume? Will you increase the TI time or will you change the cycle to very high? I don't have the polling in this, but in the interest of time, I will just try, the answer is increase TI time and I'll just go through why the other choices will not be right. The first thing is changing the mode to pressure control. This thing will not kick in until the time your TI min has been changed. So remember that. It's a Trilogy Evo devices. You do have TI min and max. Even if you change to pressure control and the TI min is low, it won't do anything. So changing the mode will not help that the TI min is changed. Targeting increasing your tidal volume, yeah, that seems intuitively right. But remember, this patient on the download had an average IPAP of 15. So you're already maxing out on your pressure support. So even if you went up on your target, you're sealing this patient. So no matter what you do, nothing will change. So you have to be mindful of what your settings are. You have to make sure you're not sealing this patient in any ways. So this thing will not help you. Changing the cycle to very high, we have briefly discussed what cycle is. That's when your IPAP will get switched over to EPAP. So if you're making it very high in your Philips devices, you're causing early termination. Early termination means this thing will stop here. You don't want that, because that is reducing your area under the curve. You're reducing the tidal volume even further. You're worsening the tachypnea even more. So that will not help you. So the bottom line over here is increasing your TI min will help you with this patient to improve your tidal volumes, improve the gas exchange, and then eventually hopefully the tachypnea gets better. So it's a 56-year-old gentleman with OHS, comes to Sleep Lab for regular follow-up. He's an astral and post-discharge. You're called from the DME company, which usually doesn't happen, but sometimes it does, that the patient's exhaled tidal volumes have reduced. So you call the patient, you get him to the clinic and see what is going on. So this is a download. The usage has been pretty decent. And these are the tidal volumes. You can see it is close to 413.95 percentile, but I think the target was much higher. Over here you're seeing it's kind of hitting the pressure support range, but you still have some gap. And you would wonder why the tidal volumes are not going up. We have already emphasized this a lot many times. Please make sure the leaks are adequate. And you should know the leak calculation will also get messed up if your mask interface is not accurately entered. So make sure you know whether it's a full face, whether it's pillows, whether it's your nasal mask, because that will change your calculations. So this is just an algorithm how to approach low exhaled tidal volumes. You check for compliance, check for leaks. Once the leaks have been fixed and you still have issues, make sure your IPAP is adequate. You're not sealing this patient. And sometimes you have to remember the RAD device IPAP max is different from your home ventilators. If you think that is causing, that might be a reason to change over to a ventilator. The other important thing is, if that still doesn't help, you have to make sure the IPAP settings are adequate also. Because remember, no matter what I do with my tidal volume, if my upper airway is collapsed, that volume is not going inside. So you have to make sure your IPAP is adequate. Usually you will not encounter these issues if you are doing auto IPAP most of the time, but you have to remember that. If your IPAP min is also kept very low, it takes a while for the whole, it might take a few hours for the IPAP to reach adequate settings. So if you're looking at a download and the patient needed an IPAP of 12, your IPAP min is set at 5, you're wasting your time. You want to push the IPAP min closer to what the patient requires, just to save time and improve their ventilation. So again, if the leak is high, you're increasing your IPAP, you're messing it up. Please keep up. I think we have emphasized a lot many times, but leak is very important. My next case. So which of the following settings will not help augment your tidal volume? The trigger sensitivity, increasing TIMN, reduced rise or increased pressure support. Just in the interest of time, the trigger will not do much. The trigger sensitivity, if you're changing that, it will be changing your minute ventilation and your breath rate. It doesn't really augment your tidal volume. So just remember that the other things we have already emphasized, they take care of that. This is briefly, once you know the ventilation things, overnight pulse socks and TCMs are very important. Your DMAs should be able to help you with it. So this was a patient that was desaturating overnight. And just quickly going at, whenever you get overnight pulse socks, make sure you review it properly. There are artifacts that can mess up your downloads. So look at that. The other important thing is on the same night, you should be having your download and reviewing that with the same night when the pulse socks was done. When you get discrepancies, that becomes an issue. So in this particular patient, he was overnight desaturating. He was tachypneic on the download. These were the IPAP pressures and the tidal volumes. The leaks were within range. But when you look at the download more carefully, this patient was achieving the tidal volume, was achieving the max pressure and your pressure support max. So things were going fine, but this patient was still desaturating. So what it brings down to is, you have to increase your tidal volumes and make sure when you're doing that, you're improving the ceiling, you're changing the ceiling also so that the patient and the machine can take care of those things. So this patient improved after that. So just in summary, and thanks to Dr. Wolf for her slide, before you start, know the device, know the prescription, check the compliance, your mask fit, your efficacy, and make sure you're achieving the targets of tidal volumes and your respiratory rate. If things are not working fine, you have to see whether your pressure support is good, your TMN is good, and then obviously getting the remote monitoring done as soon as whenever you can. And please review the download on the night when that pulse socks was done. Thank you so much for your time. Please evaluate our session. And then our last session today is going to Jorge Mora, he's going to talk about the use of dialosin during exacerbations. Hello. Well, I have not much to add to everything that I've said, everything that has been said. So I'm going to be very brief, so we'll have some time for questions. This is a case of a 56-year-old man with a history of hypertension, and importantly severe obstructive esliphapnia and mitochondrial myopathy. And the patient had a recent surgery, and interestingly had an astronautomy as well, and he was found to be hypercarbic in the post-operative period with CO2s in the 60s. This is an interesting X-ray, the X-ray is on the left, and the one on the right is a scout CT, which is essentially a supine X-ray. And you can see the significant difference in the length of the apex to diaphragm distance on the right side especially. These are PFTs that demonstrate the same, the same thing physiologically, this is upright versus supine spirometry, and there is a reduction around 30% in both FEV1 and FEC. The patient underwent a baseline study and also underwent BiPAP-S in-lab titration. Notice here that even though there was some relatively good control of the apneic events in the titration with the pressure support around 10 at the end, there was never a true improvement if you see the line at the bottom, the black line that is arrowed black as well, that's PCO2, and that's transcutaneous CO2. Even though there was appropriate control and pressure support was progressively increased, there was always persistence of hypercarbia at that level of pressure support. The patient was placed because it worked, there were no significant apneas on 23 over 10, was readmitted later with acute and chronic hypercarbohydrate respiratory failure. The CO2 has not changed at all, which is not surprising based on that titration. And the patient was transitioned to non-invasive ventilation via AVAPS-AE with PC mode on. And the settings were this, and interestingly if you see here, the EPAP min and max were placed both at 5, which essentially eliminates in practical terms the auto E function. The patient had lost a lot of weight during this period, so it might not be inappropriate. One of the bad things is this patient was placed on a Trilogy device from Philips, and those devices, interestingly enough, they're not allowed to see if you have any residual apneas on the Trilogy download as compared to ResMed and Astral devices, which allows to see if there is any residual apnea. So when you set AE on a Trilogy device, you're assuming the apnea is being treated by the algorithm, but you have no true proof that that is the case. As you can see here, PC breath was on, hence there is a TI, a mandatory TI of 1.4, rise was set at 5, and you see the ceiling of the PC max is around 18 centimeters of water placed there. The patient responded beautifully. This is a home overnight transcutaneous CO2 measurement, and the patient drove beautifully in the almost eukaryotic or hypokaryotic levels. So his CO2 was normalized on AVAPS-AE with the PC on. This case is, the title is about an exacerbation, but what this case is about in reality is how the settings were managed in a way that what we were seeing was wrong in the download was corrected, but they did not stop the patient from undergoing the original clinical course. And let's say this, let's see this. The patient came from a routine follow-up visit, increased diurnal fatigue, feels weaker, remember, there is mitochondrial myopathy here. The CO2 that was low, I mean that was normal in the recent overnight to come, was elevated. And what you can see there is in the last few days before that visit, there is a progressive decrease in minute ventilation. And when you try to correlate that with tidal volume and pressures, what you will see is that the tidal volume accounts for a lot of that reduction in minute ventilation. You see that it went from the target around the mid 500s to around the high 300s. And there was a significant increase and progressive increase that parallel that reduction in tidal volume in pressure support. What this is telling you is that there is a change in lung compliance. There is a change in lung mechanics. You're using more pressure and driving less volume, assuming, of course, that the volume that is being measured is accurate and the increase in pressure is not necessarily associated to leak, as my colleagues have discussed many, many times. And when you see that, yeah, there was an increase in leak, but it's a leak that the ventilator should be able to manage is within the range the ventilator should be able to compensate for. So that's probably not the last explanation. This is very interesting. It was not supposed to be here. I don't know how this turned into this slide. This morning, it was just a slide with four options. Here we go. And there are four options. So what I want to drive you through is the options where you increase the IPAP, you increase the IPAP, you increase the inspiratory time, and we'll see what the other one was. The increase in pressure control to a max of 25, as my colleagues discussed, that will translate, obviously, in an increased level of driving pressure, and that will translate into an increase in tidal volume. So that's probably one of the options that is feasible to do here. The other possibility that I put there was to increase the respiratory rate from the set rate at 14 to 24. There is a problem with this. And the problem is that you can use simple math to calculate what your TI, your IE ratio is going to be. So if you increase the rate to 24, your respiratory cycle is going to be 2.5 seconds. We already have a mandatory TI of 1.4, which leaves you at 1.1 seconds of expiration, which means this is going to be essentially an inverse ratio ventilation, which is not the best of the ideas. The other option was to increase TI to 1.6 seconds, and I think that was an adequate option, as was discussed in the previous cases. If you increase the TI, you increase the time that pressure is delivered, hence, assuming the same long mechanics, you're going to increase the area under the curve, and you're going to increase the tidal volume. If you increase the EPAP, probably not the best of the ideas. You're going to shift that bottom line, and you're going to actually decrease the area under the curve, reducing the tidal volume. And it's not necessary in this case, this is what we have seen. So what was done is the pressure control was increased to 25, TI was increased to 1.6, volume improved as expected, the patient continued to worsen clinically and was admitted 10 days later with acute and chronic hypercarbia with a CO2 in 66, was in septic shock, happened to have pneumonia, was intubated, and did well, eventually, despite everything that was known for the patient before it was admitted. So this is a proof that these devices gives you extremely useful data, if it's being monitored, that ideally, it should be managed with alarms, if you want to put it that way, and these devices actually, you can set up user-driven alarms. The problem is they become so overwhelming that you stop paying attention to them. So it's not a useful mechanism. Perhaps artificial intelligence and looking at trends, it's what should lay in the future. This case is just a failure understanding what were the long mechanics on going underneath and just trying to manipulate parameters to correct one of the outcomes you were looking at, which was tidal volume exclusively and missing the big picture. But this, looking at this data, would have allowed us to prevent this probably, this hospitalization, looking at what was the process that was underlying. That's the point I would like to highlight. The last sentence there is what my colleagues have repeated a thousand times, is that tidal volume is an estimate. It's hardly accurate. It's an open circuit. There is leak. We don't know. So keep that always in mind. You have to think about if there is leak, you have to think about other variables before you act and change settings for tidal volume changes. This specific example was about a Trilogy ventilator on Kerakos radar download. But the same principles are applicable to any other device that is used for non-invasive ventilation. You can see tidal volumes. You can see eye ratios. All these reports include these variables and they can be used in the same fashion.

PAP therapy

adjusting settings

download data

variables

leak

pressure

tidal volume

monitoring compliance

patient outcomes