Hello Friends 👋
Welcome back to another episode of the Incubator Podcast, where we continue exploring the management of respiratory distress in neonates. In this episode, we have the pleasure of welcoming back Dr. Lonnie Miner, who brings his wealth of knowledge in neonatal respiratory care to our ongoing discussion.
Dr. Miner dives into the critical topic of weaning neonates from invasive ventilation, he discusses the need for standardized extubation guidelines, sharing insights into the criteria for successfully transitioning from high-frequency ventilation to conventional methods, and ultimately, to non-invasive supports. The conversation also covers the nuanced differences in managing various neonatal pathologies, highlighting the importance of individualized care. An interesting aspect of this episode is the exploration of different non-invasive ventilation modalities post-extubation, such as CPAP, nasal IMV, and NAVA. Dr. Miner provides a detailed analysis of each method, discussing their advantages, limitations, and appropriateness for specific clinical scenarios. He stresses the importance of understanding and being consistent with the chosen method, ensuring it meets the baby's physiological needs.
Enjoy!
Our heartfelt thanks to Fisher & Paykel for sponsoring this series.
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Watch the video below to learn more about how interface design can affect your therapy outcomes, or for further insight into the evidence, download the NIV in NICU Clinical Evidence Summary Booklet.
Fisher & Paykel Healthcare offer a full neonatal care continuum which helps provide the best start possible to our precious babies worldwide.
To help demonstrate the importance of interface, Fisher & Paykel Healthcare have created a neonatal airway simulator (Baby LIV) which is based off a 28–30-week gestational age neonate. The simulator helps visualize pressure and flow therapies. For more information and to book an in-person demonstration, go to https://www.fphcare.com/us/hospital/infant-respiratory/cpap-interface-design/
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Short Bio: Lonnie Miner completed a degree in microbiology at Arizona State University followed by medical school at Saint Louis University School of Medicine. He completed residency training in pediatrics then a fellowship in neonatology at the University of Utah/Primary Children's Hospital and has worked with Intermountain Health since completing fellowship in 2004 (after spending 3 years working in urgent pediatric care with Intermountain as well). In addition, Lonnie was a full time faculty member with the University of Utah Division of Neonatology from 2015-2022 and continues to function as an adjunct assistant professor with rotations at Primary Children's Hosptial NICU on a regular basis. He has an interest in program development within neonatology and has been involved with development of neonatal programs within Intermountain Health since starting there. In addition, he has a focus on neonatal infections and is an active member of their Antimicrobial Stewardship Committee and has worked with the University of Utah/Primary Children's Congenital Cytomegalovirus Committee. As a practicing neonatologist, he naturally has an interest in respiratory management of all babies but has a developing interest in managing respiratory illness in the extremely low-birth weight baby as well as managing long-term chronic lung disease. Recent research has focused on non-invasive ventilation and different approaches to management. While there are many approaches to managing the respiratory status in the preterm infant, he is a firm believer in working toward more consistent approaches based on a solid understanding of neonatal physiology (with the understanding that it is changing at different gestational ages). Having been mentored by incredible teachers such as Dr. Don Null and Dr. Bradley Yoder, he strongly believes that the best approach is one that manages each infant based on the pathophysiology of their current disease state and it is vital we have a solid understanding of the devices we use to provide support and use them accordingly.
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The transcript for today's episode can be found below 👇:
Ben: 1:06
Hello everybody, Welcome back to the Incubator podcast. We are back with a new episode of our mini series on the management of respiratory distress in neonates flow versus pressure. And we are back with one of our guests, Dr Lonnie Minor. Lonnie, how are you today?
Lonnie Miner: 1:22
I'm well. How are you today?
Ben: 1:24
I'm doing good. I don't have to read your bio because you were on a previous episode, so that makes my life much easier, and definitely you're here today. How are you?
Daphna: 1:31
I'm here. Glad to be here, thanks.
Ben: 1:34
You want to take this on.
Daphna: 1:35
I will. Okay, I have a big first question. I think we were just talking about this off air. There's still lots of questions about these questions, but we'll talk about what we do know and what we have yet to learn. So we are talking really about kind of the weaning process now. So we'll start with, say, an intubated baby, baby on invasive ventilation that we're hopeful will extubate and stay extubated. Any recommendations on what we can choose post-extubation to reduce the risk of extubation failure?
Lonnie Miner: 2:11
That's a good question. I think there's a lot of different thoughts about that. First of all, the biggest step is get the baby extubated. That's when you talk to some of my mentors over the years Brad Yoder and Don Null they were always like at least get the tube pool. That's step one right. We're always a little worried about that. Sometimes I think we miss our windows for doing that. We have a baby that's maybe in a position and we can talk a little bit later, if you want, about just thinking about having some standardized extubation guidelines. That's actually something we've worked really hard on over the years.
Daphna: 2:48
I mean, we can start there. Actually that sounds great, yeah, please.
Ben: 2:53
Yeah, because I think that was entertaining. I wish I knew who came up with this, saying it's like if you have 100% extubation success, you're not extubating enough.
Lonnie Miner: 3:04
Well, I think that's Don Null actually. So at least it was for me. The two sayings from Don that I remember is if you're not re-intubating about 50% of your babies, you're not trying hard enough. I don't think Don ever re-intubated 50% of his babies. But the other saying that we quote Don a lot for us if all else fails, go look at your patient. So those are the two no-isms that we throw around. So one of the things we've tried to do is so, first of all, within the Intermountain System we use a lot of and in the University of Utah we use a lot of high frequency, primarily the oscillator. We're using a lot more high frequency jet ventilation, especially for our smaller babies, not just one set of issues. And there's been some attempts. One of our colleagues, jessica Davidson I don't know if you guys have ever talked with her, but she's very much in line with using the jet for small babies and she's working towards maybe getting us to use that as first intention ventilation rather than just as a rescue which, and there's a number of places that do that. Anyways, the gist is so we have criteria where we try to set both with extubation directly from high frequency as well as extubation criteria for our conventional ventilator settings. So we use mostly volume guarantee for our conventional as well. So for the oscillator, we usually want to see our mean airway pressure somewhere. 10 seems to be kind of a normal number for the smaller babies, maybe a little lower For the bigger babies. Maybe you can be a little bit more liberal. Definitely, if you're between 8 to 10 on your mean airway pressure you should be getting that tube out, depending on your hurts you need to look at. Your amplitude can be variable and you just need to have a thought process of are we going to do? Okay, but I think you should err on the side of can I get this tube out? So the biggest thing is and then for the jet the jet's a little more tricky for directly extubating off of and I find that sometimes we get stuck on it. So having some kind of criteria as a group to say when we get down to and people forget sometimes on the jet to look at mean airway pressure, I'll have a lot of times people report here's my pip, here's my beep, here's this, here's that, here's my rate, and it's like, well, what's her mean? And they're like, oh, then you have to go back and you look at it and so I think you can do that as well. As you know, as your mean airway pressures come down, you know, think about what? Can we do this noninvasively? And then when we, when we're looking at conventional, we use a lot of volume guarantee, as I said. So we're looking to see if we've got a kiddo on, say, pressure support volume guarantee or assist control volume guarantee or something like that. Then you know, if our, you know we want to get see our title volume down to about at least five per kilo, although sometimes you don't always have to be there. Sometimes on the smaller babies some folks would prefer four and a half and I usually like to see. I don't really fuss about the peep a whole lot, partly because I know that I can deliver peep noninvasively.
Ben: 6:16
I'm curious to hear your thoughts from your experience, because I mean, it's changing so rapidly that I think we've all seen this, where our approach to the weaning of a baby towards extubation has dramatically changed, where you you hear right endotracheal tube, cpap, and we were. We were trying to get these two, these babies, to demonstrate to us in quite sometimes ridiculous fashion that they would be sustaining the extubation, and then we found out that maybe doing these interventions and letting them be so long with so little support may actually be more damaging than anything. Can you talk a little bit about how has our understanding of this aspect of extubation medicine evolved?
Lonnie Miner: 7:00
Yeah, and so that's one of the biggest issues you need to keep in mind. So the one last thing with the weaning off the volume guarantee is I usually do like to see my pips down, you know, in a range, you know, 14 to 18, you should be thinking about getting that tube up, and if you're around 20. So the biggest thing is is just remember an endotracheal having. You know, I think it was. Dr de Blassey has a nice review article I might have mentioned last time, where they talk about, you know, the need for intubation and noninvasive ventilation, and one of the phrases that's come out over time is the phrase endotrauma, where just having that endotracheal tube in place causes ongoing not just lung damage but also you're bypassing all of the protective mechanisms of the upper airway. And then there's just this huge cytokine release. I think anytime you have a piece of plastic in a baby, one of our he just recently retired, kurt Albertine has had some very nice lab model studies where he's shown just the overall cytokine release that happens just from the intubation process but then also having that endotracheal tube in place. So I think the sooner we can get that tube out the better, and I think there's even a large cohort of folks that would even say not, you know. Of course, not putting a tube in in the first place is a good thing too, but there are some babies that you know may need it for whatever reasons, and we manage that. But getting that tube out sooner than later is absolutely a good thing and you can always I know this may sound. You know you don't want to re-intubate a baby if you don't need to, but if you need to we have the skill and we have the ability to do that, so it's worth a try on. I think the vast majority of babies you know earlier in their course.
Daphna: 8:44
Okay, so that's very helpful, and it sounds like a lot of units are moving towards standardizing that approach. I think. So we keep each other accountable for for for getting breathing tubes out Excellent. So then what?
Lonnie Miner: 9:03
There's a lot of debate on this and I think if you look at I think it was a recent Cochrane review If you look at the Cochrane reviews and if you look at a number of the data, it's kind of neck and neck CPAP versus nasal IMV. And I think, depending on who you talk to and what meta analysis you look at, I think in this age nasal IMV slightly wins out over CPAP. And one thing we didn't really talk about is don't forget about NAVA. More and more units are using the NAVA, both noninvasively and invasively. That's another one that if you're bringing that into your institution or have used it for a long time again, having those extubation criteria is critical. We're just now bringing NAVA into our institution and I've actually found that that's been very successful A lot of times. What we'll do for kids on conventional switch them to intubated NAVA, get a sense where he's at, extubate him to noninvasive NAVA once you get your NAVA levels down to a certain point, and then that has been very nice, I think. So I think the biggest thing is, as a unit, trying to be consistent in how you're going to manage it. If you are going to go to nasal IMV before you do CPAP, making sure that, first of all, you have an interface that's going to give the kind of support that you're looking for, and each individual needs to, or each group needs to, decide what interfaces work best for them, whether it's a FlexiTrunk kind of model, hudson prongs, the RAM can, high flow cannula there's a lot of different ways to approach it. With nasal IMV, I think it's important that you pick the type of nasal IMV you use and I know that sounds funny, but there's different approaches. There's a high frequent, there's a more of a high rate with a lower eye time that, in some of the studies I've done, may not be giving you as much of a recruiting breath as you think you're getting. You get a lot of little sharp spikes and you don't always overcome your subglottic closure. I tend to prefer a little bit of a longer eye time, depending on the baby, as well as in a little bit of a shorter rate based on that eye time, with the idea of being that you're giving a little bit more of a recruiting breath, you're overcoming your nasal airway and your upper airway resistance, overcoming some of the subglottic issues and then kind of giving a little bit more of a recruiting breath. I actually use an eye time of 0.8 to 1, with a rate of around 20 with the idea and it's kind of a bipap almost system. But when you look at waveforms with the pressure versus time loops they actually give just this nice even waveform that almost looks like vent breaths and then the idea is then the baby can then flutter, breathe around. That If you have apnea, different story and maybe you need to address that. So I think choosing your mode for each baby, I think it's also important. Cpap, even if a baby is having apnea, is not a bad way to go either. Just making sure that you're providing the level of support that the baby needed. If they were on a peep of eight when you were extubating, probably putting them on a CPAP of four isn't going to fly. At the same time, babies can have apnea and do well on CPAP. Based on just the idea of pharyngeal distention and being able to induce you improve their respiratory drive just from the nerve stimulation that happens from that. So I think each unit needs to have a process and then, if something's not working, I think it's important that you have a thought process on how you're going to adjust things before you re-intubate. So almost having re-intubation criteria and having a discussion about that. So if you're going to start with extubating to CPAP, then are we going to go to nasal IV first or NAVA first or as a before we re-intubate? I don't know if I said that very well.
Ben: 12:49
Yeah, no, but there was a paper that was recently published, I think, in the archives, that looked at the how valuable is it to have re-intubation criteria, and one of the conclusions, which was not really surprising, was something to the effect of this is super variable, everybody's doing different things, but it is interesting to set the metric as to. This is when we extubate and this is when we do re-intubate. I think that one of the things that seem to be a misconception as well in the community is that there's a staircase towards extubation, that I must go through these steps in order to win my patient Meaning I must go from the oscillator to the conventional, from the conventional to NIMV, from NIMV to CPAP, to high flow, to regular flow, to off, and I think we fail sometimes to understand that no babies can be extubated straight to CPAP. And I guess it's interesting because you were mentioning this Cochrane review that showed that NIMV is risk going to lead to less extubation failure. And you may say, well, if you do that for everybody, then sure you're going to have some kids that would have done well on CPAP, that are going to do fine on NIMV as well. How do you? How do you now? I mean you've answered a little bit some of that already, but how do you make sure that the culture in the unit doesn't lean too far into the more conservative approach which is like let's go in a very slow fashion because the evidence clearly says you can go from intubation to CPAP and that works?
Lonnie Miner: 14:15
And again, I think that is a culture issue and it's largely first of all deciding as a group that this is how we're going to approach it. I think consistency is the most important thing. The biggest feedback I get from our bedside caregivers is frustration over consistency, that they know that when Lonnie's on, we're going to do this, when one of my partners on, we're going to do this, and they try to adjust for it. But then if you're changing, depending on how frequently you, you know, change service, that can become a very frustrating thing for bedside caregivers. So, actually incorporating your respiratory therapy group, your nursing group and your medical group, but I think first you as a medical group have to have to be consistent and send consistent messages to the, to the unit, as well as your respiratory therapy leadership and your nursing leadership. I think those are key players. That's difficult and we get caught up in in. So we had a kid with chronic lung disease and this is I'm going to tell on myself for a second, if that's okay. So we had a chronic, a kid with fairly significant chronic lung disease recently that we had done a dexamethasone burst, and again we can have a whole discussion on on how we manage decks. That's a whole other issue. But regardless, I do think if you're starting dexamethasone you should always have some goals. You never, you know. Sometimes that goal is don't die, but in most cases you need to say we're moving some towards something and that typically should be extubation. So we had a kiddo that we were just pleased that we were able to wean his ventilator significantly, have him stable on a conventional mode that he was more comfortable on, and he was doing well and I was very much like, oh, this kid's going to take, oh, it's going to take weeks before we're going to have him ready and is this is going to be? And he'd already had issues with with respiratory infections and just was struggling. So I had a partner that she just I could tell I was looking at her going, you're not listening, you're not agreeing with this. I could see it in her eyes. So by a three o'clock that afternoon she actually had the kiddo extubated and a noninvasive novel and then about three days he he three or four days he went to CPAP and within a couple of weeks he's now on a high flow of eight and he's doing fine. So I think, having conversations with each other and maybe moving outside of the box and his his title volume was higher than I normally would have and things like that. But she was like we got to get this tube out and her point was is I can put the tube back in if he doesn't do well, but we really need to use this opportunity to try to move things forward. So I think talking as the group and good communication is is really critical, and I'm not always perfect at that, so it's it's something I'm learning.
Daphna: 17:07
Well, I I'm going to pose this to to both of you, um, about Ben's point about the right weaning trajectory, do you think we even have enough data to support, you know, standardizing it? Maybe not in a unit, but, uh, you know, as a, as a community, I can definitely see the value of seeing the standardization in any unit, and we've said that in the past. Uh, maybe having a standardization is better than necessarily the most evident, the, you know, the most up to date practice. It's more important that everybody's doing the same thing. But is there enough evidence, um, for us to say what the what the quote, unquote right way is?
Lonnie Miner: 17:47
I don't think so. I'm going to be honest, so I'm just going to. But I think there's enough evidence for us as groups and this may be something that we need to, you know, as a community, work on a little better and say let's do, whether we do it through the NRN or we do it through some other, some other method of of maybe doing something on a wider basis and saying let's do, uh, let's come up with something. So we've recently developed some BPD guidelines in the in the inner mountain um community, where we're trying in all of our, in all of our level three NICUs, to be consistent with how we're going to manage things, both getting them to extubation Like I mentioned, we already had extubation guidelines, but being more fastidious on that and then having, you know, having a set guideline on what we're extubating to, and then, um, our weaning process. And then we're we're trialing the keeping them on some form of mild positive pressure, um, through 32 weeks, um, just as if we can help. There's some thought, you know, in the community that we can help induce um alveolarization and avoid the, the kind of the quote unquote new BPD which, um, most of us feel is consistent with alveolar. Simple, you know simplification. So you know, maybe we can help induce some, some uh, um, some lung growth just by leaving them on a little bit of um people over time. So but again, I think as a, the first step is, I think, for each system to try to decide among themselves how they're going to do it and then, as a larger system and as collectives of of NICUs, try and do some of these and maybe see if we can get this published and get some information out. I think it's important that you remember the underlying physiologic process. There may not be one right way, because there's probably several. There's several different approaches that you can achieve the same end and people's experience and different providers you know their different providers experiences may lead them to choose one over the other.
Daphna: 19:49
So and now what I hear you saying also is that um different, potentially different pathologies of why why somebody's intubator or how long they've been intubated may, may change your, your weaning process.
Lonnie Miner: 20:01
Oh, that's yeah, absolutely, absolutely, and that's something I should have mentioned earlier is, you know, I think there's a big difference between a term neonate that was was intubated for maybe just apnea related to some delivery processes or medication maternal medications versus, of course, an extremely low birth weight. And even with our kids with RDS. I do think there's a difference between our 28 weekers, our 26 week or 26 weekers, and I think the new area that we're really all struggling with somewhat is that, you know, 22 to 24 week, you know, maybe 26 week kind of baby, because I think we're going to have to start thinking a little differently. Their physiology is different, their lung growth is different, they're in a different stage of lung development and I think what's worked for us in the 26 to 28 week or may not be the right thing for the 24 week.
Ben: 21:04
What's interesting is that after extubation happens and we have a baby on noninvasive support, then comes the dilemma of how do we proceed from there. Because I think many times we go to Hudson prongs, we go to a Fisher-Pochel mask or whatever, and then we saw maybe the babies have been uncomfortable with, would prefer something like maybe an optiflow, but then we have to mitigate. How do we manage the comfort of this baby that just got extubated versus the amount of pressure that I think this baby needs? And I'm curious if you have either advice or maybe a standard way that you're doing this where you say after extubation, I don't change my interface for X amount of days, or something along those lines.
Lonnie Miner: 21:47
That is one of the things that I mentioned on our extubation criteria. So, first of all, the BPD guidelines that we've gone out are for 28 weeks and less and can be extrapolated up to 32 weeks, so that's a little different than your and, like I said, your older baby or your 34 week baby that needed some initial help, maybe needed a dose of surfactant, was intubated Again. There's, though, a lot of different approaches for trying to avoid intubation in those babies, like Lisa and other things. I'm sure you guys have another podcast coming up on that. So, as far as that goes, I think, first of all picking the understanding, the physiology, thinking about what you've extubated to, and then going from there. So, for example, the older babies also that I that you know are really doing quite well, recovering. A lot of times I'll go to a high. You know I'll start on either CPAP or maybe even a high flow of like eight liters. Some of the information we have, some from some of the studies that Amy Minor and I conducted along with Brad Yoder, show that we do get some pressure. You know you get a peep of about five with a high flow of eight on an artificial model that we used. So you're getting some. It just depends on the size of the baby, of course, but in general I'll go to CPAP nasal IMV if the kiddo is, is is is having more issues. Sorry, I don't know if I'm quite answering the question.
Ben: 23:16
Yeah, I mean, I guess, I guess you are in a way, but I'm wondering if you have this refractory period where you say I'm not going to switch my interface because while, like you're saying, maybe I know a little bit of what I could potentially be getting if I make this baby a bit more comfortable and put on, put on like a silicone canula, you still run the risk of not delivering the appropriate amount of pressure, and then also, am I going to jeopardize my extubation? I think that's, I think that's what's at stake. But then again, and then you have the pressure of the family. Sometimes the nurses hang on. It gets miserable, like just trying to pull away at stuff all day. It's like what am I supposed to do?
Daphna: 23:57
But I think what you're getting to, ben, is the fact, like different interfaces have different resistance right, and that really is part of the part of the equation with how much pressure we're giving.
Ben: 24:11
Yeah, and I guess the actual question I'm so sorry if I'm being too circumferential here is will you wait until you reach a certain level of support to then start tweaking with your interface, or is it fair game, as soon as the baby is extubated, to say no? If I can get this baby off to that interface right away, then I'll go with that.
Lonnie Miner: 24:31
Again, I think it depends on the patient. So that very low birth weight baby that we've been able to get extubated, I would leave them on at least some CPAP for, and the while can vary from days to a week. And in our new criteria and I should have just pulled it up, I apologize I think we leave them on it for a minimum of five days and we gradually wean. We get them to a CPAP of about five. So we start, we use high peeps. In our system, which I know there's a lot of discussion and debate, depending on where you are in the country.
Daphna: 25:02
How high? How high is high 12,.
Ben: 25:05
Let's go 14.
Lonnie Miner: 25:07
So for CPAP, most of our units are very comfortable using eight centimeters of water. We have one of our units that routinely will use 10. The interesting thing there is is I've had a number of babies that have actually been rescued, including babies that were at outside units. I do a lot of telehealth and a number of late preterm and term babies that don't necessarily need to be transferred. They can stay in the unit that they were delivered but they're needing some support and if they stay on, if they escalate. So I'll go, we'll go up as high as 10 in some of the units. And it's interesting because we don't have a difference in pneumothorax rates with the higher peeps there's. I think the biggest thing is is I'm a firm believer that pneumothoracies and lung injury comes from atolectasis first and shear trauma. So as long as you avoid that in the beginning, I think popping a kid on 10 after they've been derecruted for a long time and having some lung damage may be a little bit of an issue, so you have to be careful with that. So anyways, going back to the question of weaning, so first of all we use the higher peeps, we'll get down to a CPAP of five and we start looking at the kiddo and if they're really, and if and again, if they're doing well and comfortable from a respiratory standpoint, I don't have a problem with taking them to a high flow cannula. We have had differences in. There are differences in resistance across your different interfaces, and that's some of the stuff that my group has presented previously, like a PAS and WSPR but and we've got a couple of manuscripts that we're working on I think you just need to know what each of your interfaces will deliver, and that's what we're trying to come up with. So your best delivery comes from your more traditional CPAP systems. The RAM can, in my mind, is not an evil or a bad thing. Some people have different. There's there's strong opinions it's the world's best thing, and I think developmentally it's fabulous, and then it or it's the world's worst thing. I think you just need to know that there are limits in what it can deliver, just like there's limits in what high flow can deliver. So I think there's a spot where you want kids to stay on some pressure after they're nice and stable. They've weaned to a CPAP of five, they're comfortable. Let's transition them to something. So some folks would go to the RAM can, maybe with CPAP and that delivers. You know you can get about three centimeters of water with that. You can also do that with high flow. But I and I would say there there's very much a developmental issue there as well. But I think they should stay on some form of at least this is our current theory is maybe some form of back pressure that mimics in utero pressure. Until about 32 weeks is where we're going Some places. I think it's 34, depending on whether you're at Vanderbilt or Purnell.
Ben: 27:50
We've adopted something similar where we keep them on some form of Pp until 32 weeks to try to get more homogeneous recruitment and, like you said, try to minimize the sort of value or their simplification. That's a hallmark of new BPD.
Lonnie Miner: 28:01
What are you guys using?
Ben: 28:03
Well, we tend to not go below CPAP of five, so like if they reach up to CPAP of five then we leave them until they are 32 weeks. But we are also I would consider us not peepophobic, I guess, because we do. We do have babies on CPAP of eight, 10. But it's usually interesting enough for us, it's mostly trying to. We usually get there from like maybe a CPAP of five to seven, and we rarely start off there unless we know that there's some very anatomical reasons to really support this baby a bit further. So yeah.
Lonnie Miner: 28:34
So you know, usually started a Pp of eight and then I'll wean down from there.
Ben: 28:38
Yeah. So that's why I think we were a little bit. Yeah, we're a bit, not less daring as you are.
Daphna: 28:45
Before we, before we move away for some of those interfaces. I think something that everybody struggles with is kind of breakdown right From some of these interfaces, and there's this theory or concept of switching interfaces during the same day, right, Four hours on, four hours off, sort of thing. What do you, what do you think about that? And the trade off of the kind of derecruitment with the switching procedure?
Lonnie Miner: 29:12
I think derecruitment is the issue. I think if you're needing a Pp of 10 or eight, switching is going to be problematic and whether you go to a high flow or you go to a different form that has more resistance across the circuit, you just need to be aware that you may have some derecruitment there. And then again, I worry about derecruitment because I think you end up with, I think atelectasis is an issue and I think that's one of the things that leads us to having old fashioned BPD and so. But I think there's a place where if a kid is doing well and they're on a CPAP of five well, you can get a fairly close approximation of that with the other interfaces, including high flow. And I think there is a trade off for the developmental issues and I think you just have to be very cognizant of that. But again, if we can avoid having some long-term lung disease and manage the developmental things, I think the biggest thing is is we just need some more developmentally appropriate good action in those areas CPAP interfaces to come out and you know?
Daphna: 30:14
Okay, so what about the baby who's on high flow, making that decision to keep on high flow, stay on 21% or make a transition to either nasal canula or switching to? You know, something like what we call micro flow, but is free flowing oxygen.
Lonnie Miner: 30:36
I think that's everything from wall to micro flow, to low flow, to everything there's. I've heard so many different, so we'll call it. You call it micro flow, is that correct?
Daphna: 30:50
From the wall, kind of thing.
Lonnie Miner: 30:52
Yeah, yeah, first of all, I'm agreeing with what your unit is doing and that I like the idea of leaving them on something that provides a little bit of at least about two to three centimeters of water back pressure, just for that of the polarization until you're about 32 weeks. And again, this is theoretical. I don't think we have really good studies that show that this is too true and true and I think we need to get more data. So I think, as people are doing this, I think we need to get that published and say, yeah, this cohort of babies does this, and I'm hoping we do that with our BPD guidelines. As far as once you've reached that 32 week threshold and they're you know they're I usually will wean them gradually on the high flow. I try to get to about two liters and if they're sitting on 21 to 25%, they've got easy work of breathing. So I think the issue also becomes do you need oxygen or do you need flow? You know if, if from a respiratory standpoint you're doing well, you've got good CO2 clearance, you're not needing the flow, then I think, transitioning I actually don't mind transitioning the older kids to microflow. I have some colleagues that have a little heartburn with that because they want to know what the blended oxygen amount is. I'm like, well, you can calculate it. You know that if they're on, you know a, you know a 16th of a liter and they're ex-weight and this and that then they're, then they're effective FIO2 is, you know, 25%. In fact, one of my APPs, when she does rounds, she will always, whenever we have a kid on microflow, she actually will say baby's on 0.06 liters per minute, which is an effective FIO2 of. And I actually found that a really great practice and very useful because it put my mind instantly into the mindset of oh, this kid's on 23.2% and at our altitude, which is around 4,600 feet, that's not, that's not a bad thing. There's the issue of ROP that comes up and blended oxygen. I think that's again something for each unit to look at. I personally think it's more important to avoid a lot of desaturations. If you look at the stop-rope and some of the other trials having you know it's that initial hyperoxia followed by later variability that causes you to have progression of ROP. So I've actually had a number of babies that we've just gone ahead and leveled that out. Let them sit with higher saturations on micro flow and have actually had a regression of ROP, and so I think you have to look at you know we use babies histograms which don't have really good data or you know, but we still use it as kind of an idea. If their histogram is 25% low below what your target is, you may need to think about that.
Daphna: 33:42
I think, as we're approaching the end of our time together, I think the next thing is so now we've gotten a baby totally to room air. So how long do we wait, how long do we watch? And you know what is the criteria, even just for failure of a room air trial.
Lonnie Miner: 33:57
Hmm, I actually had one of the nurses ask me that last night because we were doing a room air trial and the baby had desaturated to 79 and then 79%. Never had any heart rate changes, looked a little dusky, came up on his own within about a minute and so we continued to watch and probably that's an area that we haven't crossed as far as setting specific criteria in our system and I don't know of any that are published, but that's probably something that we're discussing. So, in general, I think, just having good sense, and if a baby one is, I use the histograms and I think find that and we find that that's helpful. So one of the things the nurse reported is the baby's histogram was only like 5% low. You know, on room air, doing well, and for us that's a threshold that's acceptable, especially if they're not having sustained desaturations. I find it. I do continue to monitor babies as they get older because I do find that a lot of our preterm babies, especially at altitude, once they start feeding more vigorously, they increase their metabolic demands and I even warn parents that, yeah, this is great, we're on room air, we're doing fabulous, but as the baby starts eating, don't be surprised if he goes if he ends up on a little bit of oxygen. And we actually send a significant number of babies home on oxygen because of our altitude, which I know sometimes on the when you're at sea level. I've had colleagues that have come from there that have been a little freaked out by that. But we see a lot of our babies just with the feeding process, end up meeting some. So we continue to monitor them until pretty much discharge, you know, as far as oxygen saturations and following for that.
Daphna: 35:33
All right. Well, Dr Minor, thank you so much for your expertise in spending not one, but two interviews with us for this series. We appreciate your time.
Lonnie Miner: 35:44
Thank you for having me.