Transcript
Speaker: Welcome to Critical Matters, a sound podcast covering a broad range of topics related to the practice of intensive care medicine. Sound provides comprehensive critical care programs to hospitals across the country.
Speaker: To learn more about our programs and career opportunities, visit www.soundphysicians.com. And now your host, Dr. Sergio Zanotti.
Speaker: Acute respiratory failure is one of the most common reasons for ICU admission. In today's episode, we will discuss non-invasive respiratory support for adult patients with acute respiratory failure.
Speaker: Our guest is Dr. Neha Goel, an assistant professor in the Division of Pulmonary Critical Care and Sleep Medicine at the Icahn School of Medicine at Mount Sinai in New York. She's a physician scientist specializing in pulmonary medicine and critical care.
Speaker: Her research focuses on respiratory failure timing of initiation of invasive mechanical ventilation, resuscitation and management of ARDS and sepsis, both in the ICU and in non-critical care settings, and physiology of breathing during critical illness that can lead to lung injury. Dr. Goho is the lead author of the recently published American Thoracic Society Clinical Practice Guidelines on Non-Invasive Respiratory Support for Adult Patients with Acute Respiratory Failure, which will serve as the basis for our conversation today. Niha, welcome to Critical Matters.
Speaker: Thank you for having me. I'm happy to talk about this guideline today. I would like to start with a question regarding why do you think our listeners should care about this topic?
Speaker: um As you mentioned, acute respiratory failure is probably one of the most common problems intensivists manage, whether that's in the ED, on on the wards, or even in the ICU. It's something that we manage often, but the decision of how we support our patients through this acute episode of respiratory failure, but what types of devices we use also has evolved over the last decade, especially with COVID, the types of devices we use, how we manage the patients has been changing. So a lot of the times, a clinician at the bedside has many options and how do they pick that device can be very variable. And we've seen that both in the literature, but also in our own practices. in No two physicians will say that they will do the same thing for a given patient. And that can be problematic at at times. And the goal of um the goal of this guideline is to help at least put all of the data that we have thus far out there so that ah the clinicians and patients can make an informed decision.
Speaker: And what prompted or what it indicated the need of a new ATS guideline at this moment? I think a lot of the ets got the last ATS guideline in this specific space was in 2017, and it specifically focused on non-invasive ventilation. And it's used in various types of respiratory failure, whether it's like asthma, COPD, acute hypoxemic respiratory failure. At at that time, um high flow nasal oxygen didn't really take off as a modality of use.
Speaker: um And since then, there have been several guidelines that were published, the ESICM guidelines and on high flow. There was an yeah ERS guideline on high flow. But there's not a guideline that kind of integrated all of the different types of devices that we have on hand when we see a patient at the bedside. So our goal was really to try to mimic what we as clinicians experience at the bedside. um we don't When we go to the patient, we have the option of one, two, maybe even three different types of devices that we could use to take care of that patient.
Speaker: But the guidelines thus far just kind of are siloed by device and not and don't integrate all of them together. So the idea behind this guideline was to say, let's get all the data out there on non-invasive respiratory support, whether it's NIV, be a helmet or a face mask, whether it's high flow or regular oxygen, and put them all together into an analysis where we can compare all the different outcomes and then maybe see which one is the best option for a given type of respiratory failure.
Speaker: Excellent. As we move forward, I would like to focus a on some of the guideline methodology and just an overview. And perhaps we could start with reminding our audience on the great methodology that was utilized. What's the difference between a strong and a conditional recommendation?
Speaker: The strong recommendations basically mean that based on the evidence that the panel had at hand and all of the considerations that they took during the evidence to decision um framework meetings, we decided that using a particular therapy,
Speaker: could be applied to nearly every informed patient. For example, most patients might benefit from one therapy, but when it's a conditional recommendation, but with a strong recommendation, we can confidently say that nearly every informed patient or provider would want to use that and could you and could reasonably benefit from that device. i see These are the recommendations that have the strength to actually become policy. A conditional recommendation doesn't actually mean that you know we don't use it in patients, it just means that it's the right choice for most patients. Most patients for the decision will really depend on the patient, the expertise of the team, and like what types of resources you have. So there are some and some recommendations that we make that have really strong evidence
Speaker: But we had to downgrade the ah recommendation from strong to conditional because maybe not everyone knows how to use it. So you can't apply it to every patient in the that that you might and encounter. So and the panel really, what what we do is we take all of the different evidence and all of the other considerations into, um all the other considerations We take everything everything under consideration before we make the recommendation a strong one or a conditional one.
Speaker: Perfect. And I think it's important, as you were mentioning, that sometimes also a you have to operate based on the available evidence, right? And there might be evolving evidence that eventually in the next iteration of these guidelines might change some of these recommendations in terms of the level of evidence. But you're also trying to give clinicians guidelines in terms of how to apply this and this knowledge at the bedside.
Speaker: Definitely. And I think if you think about um the ATS guideline that came out in 2017, the ATS-ERS-NIV guideline, um the study that I think really that launched high flow, the Florale study, was published in 2015. But...
Speaker: it didn't make it into the evidence yet. um Nobody was thinking, let's like see how does high flow do versus NIV and like to make a guideline off of it. But now I think high flow has become standard of care in most practices where most people do reach for it. So putting it into a guideline with a non-invasive made sense. and And it is because of theval the the evolving evidence, but also evolving practice.
Speaker: The scope of these guidelines are determined by the PICO questions that you examined and focused on. Could you tell us what are the four clinical scenarios addressed in these guidelines based on the PICO questions that were formulated by the committee?
Speaker: Yeah, so we, the committee actually put forward and voted on the questions that we thought, you know, required, that had a good amount of evidence to answer, and also that kind of fit in within the scope of the guideline. And the way we approached it was to look at all available evidence for every type of respiratory support modality and interface across the spectrum of respiratory failure that a patient can experience while in an inpatient setting. and So it could be acute hypoxemic respiratory failure, acute hypercapnic respiratory failure. Say they progress in their respiratory failure and they now require intubation, what type of non-invasive respiratory support would you use as pre-oxygenation prior to intubation? And then after you extubate someone from their critical illness, what type of respiratory, non-invasive respiratory support could you use to help um support them in their recovery phase? So we framed it as looking at across the spectrum of acute respiratory failure in an inpatient setting, but also all of the different modalities that could potentially support the patient. during this time. So it's both non-invasive respiratory support, different modalities and interfaces across the spectrum of respiratory failure, hypoxemic, hypercapnic, pre-oxygenation, and fluished extubation. Those are the four PICOs we addressed.
Speaker: Awesome. And as we dive into each one of those, could you review the terminology so we're all on the same page that were yeah that was utilized or that will be utilized as we talk about the recommendations for each one of those clinical scenarios?
Speaker: And terminology, i i mean that the modalities of oxygen delivery of support and the interfaces. Definitely. um I think when we when we talked about standard oxygen therapy for each PICO question, we tried that meant something slightly different. For example, hypoxemic respiratory failure, when we talked about standard oxygen therapy, that typically covered nasal cannulas, non-rebreather face masks, or venturi masks.
Speaker: But standard oxygen therapy in the pre-oxygenation PICO question also included bad bad mask valve ventilation that we would use as standard oxygen therapy. So standard oxygen therapy covered the standard low flow oxygen inventory masks and non-breathers. The high flow nasal cannulas that we that we talk about in this are symmetrical, heated, humidified high flow or gas that's di delivered at high flows that can range anywhere between 20 to 60 liters per minute with an adjustable FiO2. NIV basically encompasses everything that you would think of as bi-level ventilation, where you have an inspiratory pressure and expiratory pressure. So it helps both unload the respiratory muscles, but it has that ventilatory support.
Speaker: CPAP is essentially a continuous airway pressure. um it It tends to be more for oxygenation and inspiratory assistance, and and it's slightly different than non-invasive ventilation. So these are the ah four different and types of non-invasive respiratory support that we evaluated. These are the different modalities. Now, when you think about the interface, at the moment, we have very standard interfaces for high flow. You have two symmetrical cannulas that sit in the patient's NERs. So when we talk about high flow, we're talking about a symmetrical high flow nasal cannula. um With NIV and CPAP, you can deliver it in multiple multiple different ways. You can deliver it via a standard face mask, which is what most people in the United States are for.
Speaker: familiar with, but except for some centers, and you have a face mask that goes either over the nose and the mouth, or some some centers have ones that go over the entire face, but it's it's a face mask, essentially. um And then there's also the helmet interface, which is essentially like a clear hood that encloses the whole head, and it feels at the neck. And these helmets are slightly And there's different types of helmets, but all all the helmets that we evaluated, just ah we didn't like break them down by the type or the company or anything. They're just all under the helmet interface. So NIV or CPAP could be delivered via face mask or helmet. And in each PICO question, we actually talk about whether we collapse them. Sometimes when there's not enough evidence for, say, helmet, and there's only like one study, we did look at the data
Speaker: all together under one modality instead of like separating it out by interface. And where it was possible, we separated it out both interface and modality. Perfect. Let's talk about acute hypoxemic respiratory failure. And maybe we could start with the actual recommendations from the guideline.
Speaker: Of course. and So we made a um so strong recommendation for high flow. um ah to treat all patients coming in with acute hypoxemic respiratory failure. um And we suggested the use of NIV or CPAP by either a face mask or helmet over standard oxygen therapy, and those were conditional recommendations. And we made no recommendation when comparing between high flow and NIV. So we made a strong recommendation for high flow over standard oxygen therapy and a conditional one for NIV or CPAP over standard oxygen therapy. and this is for patients who came in with de novo acute hypoxemic respiratory failure. Someone who has pneumonia comes in with worsening oxygenation.
Speaker: but that those were the people that we included in the data. And in terms of the rationale behind these recommendations, could you comment on some of the most salient recent studies or literature that supported these recommendations, and special especially the strong recommendation regarding the use of high-flow nasocannula over standard oxygen for these patients?
Speaker: ah Definitely. So I think Perhaps we should take a ah little step back and talk about the the grade process again to kind of explain like why we made the recommendations that we made.
Speaker: um When we set out to write this guideline, one of the steps of the grade process is after you pick your PICO questions, for each PICO question, we have to identify outcomes that we think are important to both students like that we think are important for patient care, but also that are patient-centered outcomes. So that the outcomes that a patient would care about. And these can be mortality, they can be comfort, they can be across, you know, they can be anything from mortality all the way to comfort to post-ICU, morbidity. And based on what
Speaker: and based on what the panel and the patient representative felt were important, we rate all the different outcomes as being critically important to the guideline versus important or maybe not as important. And then that helps us kind of put the evidence into context. For example, there might be a study that showed, you know, this high flow is really very comfortable, but that we didn't find that comfort was such a big part of, it was as important as say mortality, then the evidence, the weight of the evidence is differentially treated. So what we have, ah we we actually found, we actually said that the need for intubation and mortality were critical outcomes. And based on those outcomes, we looked at the data. And and in that setting, we found um that high flow probably reduced the need for intubation by almost 25%.
Speaker: And it may reduce mortality. And the mortality reduction was low certainty evidence, but there was a strong signal saying that high flow probably does reduce the need for intubation when when used in patients with acute hypoxemic respiratory failure. um And the harms were judged to be minimal. and Both NIV and CPAP also may reduce the need for intubation, but that was much less effective.
Speaker: that that strength of evidence was ah less than that that, the evidence that we had for high flow. the The signal for mortality wasn't there for both for both interfaces. What's actually interesting is that Helmut NIV had a much lower reduction in intubation than both high flow or NIV via face mask. But The problem with the helmet interface is that not many people are very familiar with how to use it. So some of that actually, those discussions about familiarity with use and harms related to misuse because you don't know to operate a specific device kind of led us to downgrade um that that recommendation from a strong recommendation to a conditional one for NIV via helmet interface. So and that's kind of how the grade process worked in how we made the recommendation for high flow, a strong one for high flow versus a more tempered one for NIV and CPAP via both the different interfaces.
Speaker: And obviously, there's also a great impact that the pandemic COVID-19 had on the use of non-invasive ventilation. I've never seen more non-invasive being utilized than in that time. And some studies emerged after that. But we're trying to kind of get back, I guess, to...
Speaker: good to the middle, right? We kind of overdid it, now coming back to the middle. But from a practical perspective, how would you interpret this for the clinician at the bedside in terms of these recommendations for acute hypoxemic respiratory failure?
Speaker: i think for a clinician, again, it really, i always like to think about the system of care you have in place. and There are places where flow is, you know, everyone reaches for high flow for a sneeze and it versus there are places where there's not that many high flow devices available. um So taking all of that and and into consideration really does um matter What we felt was that in the majority of the patients, most patients, if they have acute hypoxemic respiratory failure, perhaps the first device that I would pick is probably high flow. and
Speaker: And and that that balances some of the risks, the harms, the comfort the patient might feel using a high flow, of their ability to talk with their families versus a face mask and IV or CPAP, which is that which is the other option you have when you have someone with acute hypoxia failure who's not doing so well. and So in in clinical practice, practically speaking, you could reach for high flow um first because it might be more comfortable for the patients. It can support them. And then if it's not supporting them, you all also have the option for some patients who might need NIV to use that. I will say um the selection is only like the first part of the of of the whole conundrum. It's actually probably the easiest part. Once you you select the device, what do you do next? that's that's the real That's where the money really is, is what are the settings that you're using? How are you monitoring these patients? How often are you checking their gas exchange? how Are you escalating them, de-escalating them? Those questions are not necessarily laid out in the guidelines specifically, but we do say that most of these devices, most of this evidence comes from
Speaker: very highly monitored randomized control trials. And if you want the similar results for your patient at the bedside, you might not be able to recreate the randomized control trial, but you have to understand the context in which that care was delivered, which is in monitored settings where people were watching these patients on these devices.
Speaker: um I think that's one thing the pandemic told us is that, hey, we can probably use these devices outside of the ICU, But there needs to be some kind of a system in place where you're using them appropriately. At least that's what we learned um within our system as well, is that it's not that we can't use them outside the ICU, but we definitely need ah systems in place. There's the selection and then there's everything else that comes after, which is a lot more than the bulk of the care that we're delivering to the patient. Absolutely. And we'll have a chance to talk a little bit more about those specific topics towards the end. But as we move forward with the clinical and scenarios or PICO questions within the guidelines, I would like to shift our attention to acute hypercapnic respiratory failure.
Speaker: And here, ah probably the One of the older commend recommendations has been and on non-invasive ventilation for these patients. Could you talk about the recommendation and why does NIV remain first-line therapy here?
Speaker: i think um of all all the therapies we have, NIV is probably one of the best proven therapies in critical care, especially in hypercaptic respiratory failure. It reduces both intubation and death, and it like essentially directly treats the po problem in this particular case, which is a failure of your respiratory pump. You you can't keep up with your ventilation, and NIV directly supports that. um And we made a strong recommendation for NIV by face mask, overstander adoption therapy here. i think it's based on more than 40 trials across
Speaker: several decades in more than 4,000 patients. i don't I don't have the exact numbers, but um it it there is a large body of evidence that supports NIV as probably the first-line therapy for hypercapnic respiratory failure. um And most of these patients, their hypercapnic respiratory failure was secondary to COPD exacerbation. So in these in this in this particular patient population, that it is your go-to using NIV to support those patients. it Like I said, it reduces mortality, it reduces the need for intubation, and the evidence is consistent over decades of data.
Speaker: What's the role of high-flow nasal cannula in the hypercapnic respiratory failure? Yeah, so this was actually one of the more... discussed part of our guideline. And I think part of it is also because I think this is one of the first guidelines actually making a recommendation for against high flow and hempercapnia.
Speaker: um There are some studies that we that we included of high flow into the network meta-analysis, and they were actually well-conducted studies, but most of the patients that were in the high flow arm had milder acidemia. So these are not patients with like severe pH derangements that have like significant CO2 buildup. So these are patients who have like milder exacerbations or milder hypercapnia with, say, a pH over 7.25 higher. um
Speaker: And the other caveat that we noticed is in most of these trials, a lot of the patients on high flow did escalate to NIV to prevent intubation. So there is, but there is a, so, but given that most of these patients were on high flow and they did do well, we did make a conditional recommendation for patients with milder hypercapnia to be able to use high flow for them. especially if you're in a system or a place where you could be closely monitored and escalated to NIV if you need it. and that was a caveat we made because almost one in three patients in these in the high flow group actually did end up on NIV. But it did prevent them from needing intubation. One of the things to note is that high and high flow is more comfortable. Patients can perhaps eat while they're on high flow. So there is that
Speaker: um option of being on high flow for periods of time within escalating TANIB if you're not doing well and that is option that this particular recommendation provides um for patients with hypercapnic respiratory failure.
Speaker: Nija, could you a tell us about the role of the etiology of the hypercapnic respiratory failure in selecting the type of respiratory support? Yeah, so I We, in the guideline at least, we didn't separate out. We did do some subgroup analysis when we looked at the networks um to see if there was a signal saying that it's specifically helpful in one particular group. i will say the majority of the population that was in the hypercapnic PICO question network meta-analysis had COPD exacerbations. There were six trials that were included that had cardiogenic pulmonary edema. These were older trials, and they were primarily using CPAP as a modality and comparing it to NIV versus CPAP versus standard oxygen therapy. So we do actually um address that in the guideline and the test of the guideline, saying that um you know the bulk of the patients who have hypercapnic respiratory failure, those
Speaker: Those with COPD, cardiogenic pulmonary edema is like slightly in a separate group. NIV is probably the standard of care for that group of parent patients as well. And CPAP probably works for them. But in the broader scheme of hypercafeinic respiratory failure, like those with COPD, probably you still use NIV. and not CPAP in that group. So um thinking about rapidly reversible patients, COP exacerbations, those patients tend to do better with NIV.
Speaker: Excellent. And in terms of escalation, how do you think about, I'm on high-flow nasal cannula, now I have to go to NIV, or I'm NIV, now I go to...
Speaker: invasive mechanical ventilation, endotracheal intubation for these specific patients with hypercapnic respiratory failure? I think it it really depends um um like on how the patient does once you've selected the device. If someone comes in, in they have mild hypercapnia, they're not in significant distress, but they need some support, and you're looking and you're trying to decide between high flow or NIV,
Speaker: I would say you could go with either, but if they're a little bit more in dis distress, they have more acidemia, then those patients, I would 100% go for NIV first. I wouldn't even try high flow in them and then escalate them. You don't really want that delay in care. You want to start getting um you know getting that acidosis addressed right away. So again, NIV, high flow, everything really depends on the fit and depends on on how the patient responds. Sometimes I pick, practically I pick NIV for patients with hypercapnia and i put the mask on and they just hate it. They just don't want to wear it. They want, you know, it's not the right fit. There's a leak. um The mental status is going. And then, you know, then you can support them, maybe trial them on high flow. But again, high flow, the data is very specific.
Speaker: It's practically non-existent and more severe hypercapnia. It's mostly for mild hypercapnia. So if if you tell me there's a patient who's hypercapnic, I'm still reaching for NIV. Maybe I'll give them breaks when their acidemia is a little bit better on high flow. But I don't know that I would go to high flow off the bat for all my hypercapnic patients.
Speaker: that helps but that's more my practice and the the guideline is similar to the and the guideline supports that practice because it says strong recommendation for an IV means that most patients will benefit from it a conditional recommendation for high flow means that probably some of the patients will benefit from it but it really depends on the patient and the system of care in place Excellent. As we're talking about escalation, intubation becomes an important aspect of what we do, and pre-oxygenation for endotracheal intubation is the third clinical scenario or PICO question that the guidelines addressed.
Speaker: Why is peri-intubation hypoxemia so important? I think probably as ah and a bedside clinician, hypoxemia right before I'm about to intubate someone is one of the scariest things that I experience. It's like intubating a patient who already has respiratory failure is one of the more dangerous things we do in the ICU.
Speaker: severe hypoxemia can really set off a chain of events that leads towards cardiac arrest. so all of what we try to do prior to intubating that patient is really trying to prevent that acute desaturation that sets off that cycle of, uh, decompensation.
Speaker: Um, so I just, so, When we think about, you know, why do we care about, you know, one little mode, one, one little, blip in oxygenation is just because of what could happen afterwards, whether it's like arrhythmia, thermodynamic collapse or cardiac arrest.
Speaker: Um, and really the idea of pre-oxygenation is to lengthen that, that apnea at a time to give you a little bit more room to work when you're about to do this like more dangerous procedure that, um,
Speaker: because it can lead to significant morbidity and mortality. What was the the final recommendation from the guidelines in this area? in In this space, we actually included, I think, 15 trials um across both standard option therapy, which had non-rebreathers, face masks, bag valve masks. and we compared that as standard option therapy compared to high flow or NIV. And we found that either high flow or NIV had much better results
Speaker: like evidence to reduce serious adverse events and prevent that hypoxemia than using standard oxygen therapy. in So overall, we made a strong recommendation to use either high flow or NIV as pre-oxygenation to prevent um that for pre-oxygenation during intubation. And the data is mostly from, it's not like mortality data that we see here, but our but but the panel felt that even that hypoxemia preventing that was um a benefit enough to mitigate any any of the harms of actually putting our patients on NIV or high flow prior to intubation.
Speaker: Is there a difference between h a high flow, nasocannula, or NIV, or is there any data to support a difference? So the network analysis itself didn't show that high flow or an IV was better. i There were actually more trials that we had that looked at high flow versus standard oxygen therapy um in this group. But we obviously included Preoxy, which is a very en large, which was one of the largest trials done in this particular space.
Speaker: And that looked at NIV versus standard oxygen therapy. So that actually lent a lot of strength to to the evidence behind and i um So individually, they both had strong bodies of evidence supporting either the use of and NIV or high flow, but there isn't a strong body of evidence it's comparing the two of them And there was not a big signal that kind of said that one was better than the other in the network analysis that we did. So that, I think, is still a question that needs to be answered. Is NID better or high flow better pre-Irq?
Speaker: pre-oxygenation prior to intubation. I think with with that pre-oxy, what they actually did was they took patients off high flow and then standardized them to NIV or standard oxygen therapy, which is not exactly what we do on high flow. We might actually lead patients on high flow while we intubate them. A lot of the times that's what I do on in my clinical practice. I think one of the things that people did bring up during our discussions was if you have to put everyone you're about to intubate on these two devices, that's a lot of patients that you need to like potentially change on and then put them onto one of these devices. So really what I would say is in practice, if someone's on flow,
Speaker: I would probably just leave them on high flow. And if someone's on NIV, I'd probably leave them on NIV as a mode of oxygen, pre-oxygenation prior to intubation. But if I have someone that I'm intubating that's on neither and is just on nasal cannula, I might actually be reaching for high flow or NIV to get them on that device to just get them a little bit more topped up. So they're they have a longer apnea time and we have a better chance of intubating them without consequences. And this is certainly a change that I've seen in my and practice over time, right? 10 years ago, we didn't even think about this.
Speaker: And now it's become more of an issue. But another way that that it's been framed to me that I thought was very thoughtful and would love to hear your comments is from one of my ED colleagues who said, ah as soon as somebody comes into their ED, to their IC, to their kind of presentation area, if it's a respiratory issue and they're not looking very good, they might just put them on NIV or just put them on high flow immediately because even if they have to intubate them very quickly, this will actually serve as the pre-oxygenation instead of switching or escalating while they're in the ED. So that is also kind of fits with what you were saying, right? It's just to start with this when you're you're not sure what's going to happen if you're responding to maybe a rapid response or or in the ED.
Speaker: Definitely. And I think, um, continuing that as a mode of oxygenation while you're getting set up makes sense. And and again, like when, when you selected NIV and you have a good seal, it's like a much nicer way to, you're basically doing what you want to do with a BVM. You just have something that's already in place, properly sealed and it's delivering the brats. Nobody's hyper ventilating the patient, you know, it's, it's a lot more controlled in a way.
Speaker: Um, so I really do like the use of non-invasive respiratory support for pre-oxygenation, but I think one of the biggest, um, barriers to this particular recommendation is the implementation and actual practice. um Because people do what they do and that's part of their practice within their system. so And then to actually get someone to go get another device, that is where the implementation probably needs to focus on.
Speaker: and And for sure. And and what what what I take to my practice is a within the the scope of intubations that we do as intensivist,
Speaker: the the emerg and the emergent nature of an intubation is is wide, right? sometimes We absolutely know that we're going to have to intubate this patient who's on the floor, but we might feel comfortable transferring them to the ICU to do this in a better and a more controlled environment. And in those cases, I usually will tell my charge nurse and respiratory therapist, get the NIV the high flow ready because as soon as we get there, we're going put them on this and then we're proceed to intubation, right?
Speaker: On the other hand, sometimes you have to immediately intubate somebody peri code or during a code. And that obviously is a different situation. You're not going to delay that ah waiting for the NIV or the high flow to show up.
Speaker: This is true. And that kind of also goes back to, you know, how was um like the the the majority of the trials that were done um that ah that were done in the space that were included here, if they weren't done in like, you know, the patient that's actually actually having a cardiac arrest or is about to have it and you're intubating them. It's really like someone you are like, oh okay, I'm going to be intubating this one in the next 20 minutes. And you have like a little bit of time to actually kind of get set up. I still see a lot of practice where people are still just using nasal cannula or just using the non-rebreather mask. And I think that's what I was alluding to is Even, you know, if you're intubating in the ED, it just makes more sense to have, ah like, maybe perhaps a better way to pre-oxygenate these patients than just apne ventilation with the BBM. Excellent. Yeah.
Speaker: So the last category or clinical ah group is the post-extubation respiratory failure. And this is actually an interesting arena because the pendulum has swung from one way to the other. And I do believe it's very important to to be very clear on what's supported by evidence and what is probably not a good idea and within this category.
Speaker: So maybe we could start with a discussion of proactive versus reactive or rescue use of and non-invasive and respiratory support post-extubation and make that distinction very clear and then go to the recommendations.
Speaker: Definitely. i agree with you. That's probably the most important st distinction in this section. And our our recommendations were primarily for prophylactic use. So what I mean is putting someone on high flow or NIV immediately after a planned extubation. So this is not someone that you've extubated and don't look well and then you're using the device, but you pre-plan, hey, we're about to extubate this patient, put them on high flow or put them on NIV. And the large majority of the trials, over 80% of the trials that were included in the analysis that we reviewed to make these recommendations included was prophylactic use. And that's where I think that's where really the benefit is.
Speaker: and The rescue data is a lot more sparse and it's a little bit concerning. um Like for example, if you use it as a rescue, they've already developed some sort of respiratory failure after you've extubated them. And it may just like delay, increase the risk of re-intubation compared standard option therapy. and And it might just be, it might just delay the inevitable intubation versus actually preventing it. And the goal of this particular question was to say, hey, what can we do to actually prevent that respiratory failure? Not what do we do once that respiratory failure actually has already occurred. Right.
Speaker: and And studies have shown that when you use it as rescue, the outcomes are not better. And part of that might not be a failure of the device, but maybe we're just delaying re-intubating people who need to be re-intubated so we can cause harm, which is a problem that I saw previously.
Speaker: during COVID and post-COVID, we will talk about at the end. And I definitely would love to hear your your take on that. Going back to the post-extubation respiratory failure, what defines a high-risk patient for post-extubation respiratory failure? What are the the characteristics of patients that might it prompt you to say, you know what, I'm going to use non-invasive ventilation or high flow as my strategy of my planned extubation?
Speaker: Yeah. So i'm I'll tell you what I typically think of because we have a table in the actual guideline that goes through all the criteria that the trials actually used. But when you're practically thinking about a patient at the bedside, like what are high risk features that most of the trials included? These are like older patients with cardiopulmonary disease. And if they have a history of heart failure or COPD, they are also higher risks. obese Obese patients and those patients that actually had a prolonged intubation, all of those um are really probably the top category of patients that kind of fell in the high risk group. Again, patients who've been intubated for a long time, older, have more than like two core morbidities, cardiopulmonary disease, obese obesity. These are like the the top criteria that almost all the studies have. There are some studies where some of that changed. It's not it's not a standardized criteria um across all the studies that were included, but if had to pick the most common ones, these are the ones that I think of, especially in in in the medical ICU, they're the most common ones as well.
Speaker: Excellent. Are there any other practical applications at the bedside in this area that you want to comment on? And when you think of high flow nasal cannula or NIV after excavation, is it sequential? You combine them. How do you choose them?
Speaker: and Anything else that maybe would be helpful for our listeners? I think that's actually very interesting because that's actually some of the studies, the combination therapy is actually being studied. We didn't actually talk about that or analyze that. There was one study that actually used a combination of like high flow and NIV that was actually studied and included in this analysis. But most of the studies actually compared flow versus NIV or high flow versus standard oxygen therapy or NIV versus standard oxygen therapy. a Very few of them were combination therapies.
Speaker: The way I typically would approach a patient is if they have multiple high-risk features, NIV actually is recommended over both high-flow and standard fraction therapy. NIV patients on NIV actually do better.
Speaker: If the patient doesn't have the high-risk features, it's it's a young patient who got intubated for a pneumonia from a septic shock, you can probably get away with extubating them to high-flow. The combination therapy hasn't really been answered.
Speaker: And the other question that hasn't been answered is how long do you put these patients on these devices? Say you extubated someone to high flow and you leave, how long you do you put them on high flow? Do you rapidly win it off? Do you leave it for a few hours? Like what is that number? We don't really know because that's another thing that we don't know or If you ask any clinician, everyone will will tell you something different, at least in my experience. It's a, how do you actually wean the high flow off now that you've put someone on high flow?
Speaker: Um, so that question hasn't been answered. It's really, you have a patient who, who's after critical illness is being extubated. they don't have high risk features, I would extubate them to high flow. If they do have the high risk features, I would extubate them to NIV. I actually rarely, know, extubate anyone to standard oxygen therapy unless I intubated them for an endoscopy, then fine, I'll extubate them to, you know, standard oxygen therapy, but almost the bulk of my patients, the evidence does support extubating to non-invasive respiratory support.
Speaker: Excellent. as we As we close the clinical discussion, i want to focus on some kind of practical advice to summar to summarize. And um the first question I have, and you already alluded to it earlier, is where can non-invasive respiratory support be safely delivered? Let's start there. And maybe emphasizing also the distinction of not only the monitoring that is required but what's the indication in terms of acute versus chronic use which sometimes our colleagues seem to to miss and not understand the difference yeah no um it's actually it's one of the questions that's pleading me at the moment is um where do we use these devices i think
Speaker: Pre-COVID, if you asked us, we're a very high acuity coronary care center where an ICU bed is a very limited resource. So you have to be really sick to be end up in one of our ICUs. And most of the time, we end up managing very acutely ill patients on the floor. um But it definitely needs to have a system of care in place that allows you to do that. And not every ward or not every step down unit or a respiratory care unit is designed or are capable of doing that. most of the data that we're that we base these guidelines on has come from an ICU space or an ED resuscitation space where the care delivery is very different than, like, say, a hospital medical ward. But if you pull a lot of the clinicians that use high flow now, the bulk of them are using it outside of the ICU. and Even outside of very busy centers, we find that
Speaker: now more and more people are comfortable using high flow outside of the ICU. And that's something that happened, i think, during COVID is where we just had to get comfortable with it, and we did. And I don't know that that trend has changed back. People still just put patients on high flow. um On the wards and what i I always warn my fellows and my residents is that the patient looks great, but you you have them on a lot of support. It just looks like a nasal cannula, but it's actually a lot of support. So you want to be monitoring them very closely. And the data that you base that choice of device on was done in an ICU. It was done and in a very controlled setting. So I think I'm not, it's it's very hard now to mandate everyone on high flow to end up in an ICU, but
Speaker: it does, if they do end up on these devices, that they do need to have, institutions need to have protocols or clear failure criteria or escalation pathways. and And the guideline actually does say that, is that you really, once you selected the device, you need to know how, when you know the patient's failing and when you know that they're actually succeeding. And that's an important distinction someone to have when when you select this device.
Speaker: In terms of ah monitoring, any any additional comments you want to make of appropriate monitoring for these devices, regardless of the setting? I mean, so I know there's like, you know, different institutions have different ways of monitoring these patients. We also have some indices like the ROX index that's been developed, that's been validated in high flow or the HACOR non-invasive, although that's more specific to hypercapnic respiratory failure. There's like spores you can use. there's um There's institutions that have developed models to like assess if they're succeeding or not.
Speaker: um I think the key is to have a schedule to reassess the patient, however you do it, whether it's like using the Rox index or whether you're using some kind of a dedicated model of assessing the blood blood gas exchange, even if it's just a respiratory rate an oxygen saturation. Just having a schedule to monitor the patients so that you're continually titrating these devices is important. It's very important. and to know exactly what the escalation criteria are. Just like if you look back to the, like the Florale study, they had very specific escalation criteria that led to an intubation. so as long as we have those systems in place, whether it's respiratory rate is not doing well, they're desaturating, then you put them on, then then you escalate them before it's too late. i think one of the things that we noticed in COVID is that at least that escalation from
Speaker: didn't always happen. Like i was like, the patient looks okay. He's on like a ton of high flow and we waited for some, maybe a little too long in some patients before we intubated them. Um, just because I think that set criteria isn't always followed or isn't always assessed in some of these patients.
Speaker: And I think that that is ah an important aspect of the dangers of using non-invasive respiratory support, right, is the delayed intubations and the potential harm they can produce.
Speaker: And I agree that and that was especially evident during COVID, but I still feel that I see it in our practice these days, and it's an opportunity probably for for us to improve. and I do believe that...
Speaker: we kind of kick the can down the road a little bit too much with these patients. And you are right. If we have clear, yeah clear is maybe not the right word, but if we have established guidelines, right. And in most of these cases, it's going to work in an hour, two hours, right. If it's not working after a day, it's not going to work. Right. So we have to just kind of move forward and and other suggestions you have in terms of avoiding these delayed intubations.
Speaker: Um, I think I, I start, this is something I struggle with all the time as well, because, Sometimes you have someone on non-invasive respiratory support, they look fine, they are not getting better. And think maybe tomorrow is the day that they turn around. And it's really hard for us to know when that tomorrow comes and like to pull that trigger to intubate them. Then you know, you're going to like intubate them. You're going to be sedating them. There's going to be all all sorts of things that happened and down the road. So that risk versus the benefit, um, you're constantly reassessing. um
Speaker: i I worry, though, that sometimes non-invasive can a mask things that you might not necessarily be thinking about. You put someone on non-invasive, they're taking tidal volumes in, you know, but a liter of tidal volumes, and they're breathing fast, but now they're saturating okay, and then you're like, oh, I have supported them.
Speaker: And I'm like, but did you, did you actually support them? Because if this patient were intubated, you'd be paralyzing them to make sure that they're, you know, on lung protective ventilation. So I think that's what I try to tell,
Speaker: um people when you select non-invasive respiratory support, um think about if you were to intubate the patient, would you do something differently? Would you allow them to breathe at one liter tidal volumes? Would you allow them to to have a respiratory rate in the 40s? Like all all of those are aspects of care that sometimes it's easy to miss when you have the non-invasive respiratory support and they're not hypotensive or actively desaturating. I always try to say, if you were intubating them, would you manage their
Speaker: would you reassess their lung mechanics differently? Would you address their drive differently? Sometimes I've actually used, you know, this is we didn't talk about it in this guideline, but people talk about sedation on non-invasive or anxiolytics on non-invasive to help kind of reduce that sense of drive, which we which we can do on into and in an patient, but we can't do as well in a patient on non-invasive. So there's a lot of nuances of care, that can get missed um when when you have someone on non-invasive because you don't think they're as sick as someone you've intubated. at least that's something that I've noticed more and more is that we're more happy to let someone be outside of the roles of lung protective ventilation when they're non-invasive ventilation versus as soon as we put the tube, it's something like flips in our brain and then we're like, oh, we're all monitoring every little number that the vent delivers us. And i don't think that i don't think that's necessarily good for the patients.
Speaker: Yeah, I think that without going into a a new rabbit hole, the whole idea of self-inflicted and and lung injury, right, or non-associated to the ventilator lung injury that we might perpetuate with these modalities is still very interesting. And i think a lot to be to be studied there as well.
Speaker: Definitely. Yeah. I would like to to close ah the clinical and discussion with one or two things that clinicians should start doing and one or two things that clinicians should stop doing based on the guidelines.
Speaker: um i I hope all clinicians that, you know, that choose not to take service respiratory support, or no know that you know this is just really, it's it's a bridge to helping the patient recover. it's It's not actually going to solve the underlying problem. So a lot of it is um you have the patient on this device, you have to to do other things to get them over this acute phase. But if you see that it's not working, to not...
Speaker: to not delay the inevitable because when that inevitable the point of intubation does arrive, you have a much, you have a substrate that's been worsened by everything that we haven't done to them until that point, unfortunately. And I think that's what I worry most is that we have a lot of great non-invasive therapies. And like you said, the pendulum keeps swinging and there's sometimes where we intubate people too quickly. And then now I think, we're going towards not intubating them soon enough and just finding that right medium is what is important. And then um like to just not using non-invasive as a crutch um to pro to delay the inevitable.
Speaker: and i and then really, i hope everyone starts thinking about putting systems in place when we have non-invasive on patients, not just the escalation pathway, but the de-escalation pathway. And I think both of those are important because we have patients that we put out of high flow, but then nobody knows how they're going to come off of high flow. And we're just kind of, you know, there's delays in getting patients out of high flow that like leaves them in the hospital for two, three extra days where we're just trying to get them off the support that they may or may not need because people are scared to turn it up down and off because it worked.
Speaker: and So that's, I think that that's the next step it is really kind of defining both escalation and de-escalation pathways in patients on non-invasive respiratory support. Perfect.
Speaker: We like to close the podcast with a couple questions that are unrelated to the clinical topic. Would that be okay? Yeah, that's fine. me The first question relates to books. Is there a book that you have, that you have read that had a real impact on you or a book that you have gifted up often to other people?
Speaker: Um, it's, it's funny. Uh, when I saw the question, one of the things that I thought of was the book I'm currently reading. I actually, um, it's a book called breath. Um, and it's, it's funny because it's written by a journalist and not a scientist and it's about how we breathe as humans. And it really made me think about, um like what we, how, how I, be and and it's funny because I have a colleague who actually spends time in this clinic asking his patients about how they breathe. Do they breathe through their nose? Do they breathe through their mouth? And he actually gives them breathing techniques in addition to therapies to help them feel better. And a lot of them do. And part of it is because, um one of the things that the, the, the author talks about is, um, the, how breathing feels differently for everyone. And, um, and actually talking to all our patients and asking them how they breathe and,
Speaker: might make a difference and um i mean not every claim in the book is backed by strong evidence obviously but there are some parts that were very interesting that that i found uh that i actually tried to do there's a couple of times there's there's a section in where he's he tries to breathe only through his mouth um ah for ah for a significant period of time and he hated it and then and then we have patients who we we call quote mouth breathers and we you know and And we're like, that device is not working because he's a mouth breather. And i'm like, it made me wonder, I'm like, is he a mouth breather for a reason? Or is it just that the way he breathes is one of the, is part of the pathology? Or is it just especially a symptom of his underlying disease?
Speaker: and And I agree. and i And I did read that book and and I found it fascinating. i actually tried to do the opposite exercise and only breathe through my nose. And it was very hard.
Speaker: Exactly. It's like you, the other day I was like, I'm going to try to do diaphragmatic breathing and I just didn't know how to do that. It's like I'm a pulmonologist. But but i think I think it's a great example, Nija, of how things that we do every day have so many layers, right? I mean, everybody's breathing, they're even thinking about it. And I do agree. It it is a wonderful read and and we will definitely include it in the in the show notes. So thank you for for sharing that.
Speaker: and The second question relates to our ability to change our minds. Tell us something you have changed your mind about in the last few years. um i
Speaker: For the longest time, i'm am' not someone who adopts technology very quickly or easily. um i'm um what i a self-proclaimed Luddite, and I was like, we don't need all these things in our lives. And... um But i started off, but I i didn't actually, but i I still wasn't one of the, you know, I have two children and I'm not, I wasn't someone who was very gung-ho about preventing my kids from like, you know, being on tech or watching things on, you know, I was like, as long as it's an educational video, go ahead, you can watch it. um And i noticed though that
Speaker: there has been significant shift in how we interact as humans because we're all looking at a screen. And I didn't think it was such a big deal a few years ago, but I've noticed more and more now that I don't look up and look at the world around me because I'm looking at my screen. And I have changed my mind a lot about that, its impact on personal relationships or professional ones, because we're just all, and especially like now that we're on zoom all the time,
Speaker: it has changed a lot. I thought, why not? Zoom is so convenient. I can attend conferences after being on call. And it's just, but I do see there's been a significant shift in how we interact as colleagues. And I actually kind of miss the days of all going into work and and and sitting sitting down and just chalk talking to a colleague that you might not have seen in a while because you know you're on service or whatever. So I definitely changed my mind about technology in the workplace as well as technology in general, I think. And that's something that's been more recent. Yeah. And and and i and I agree. i I believe that it really brings to my and to my mind the idea of living by design and not by default.
Speaker: And the phones have become such a default source of our attention, right, of our focus. Like and you're if you're in the and the grocery store in line to pay, you look around people in line and everybody's on their phone, right? As opposed to maybe just being engaged with each other or thinking about important things, right? and Or you go on a walk and people on their phone. Why not just look around? I mean, you live in a big city. There's so much going on around you. So I agree. I think being more intentional of how we use things and not let the things use us, right? Definitely. Definitely. For sure. um
Speaker: To close, Neha, I wanted to ask you, what would you want every listener to know? It could be a final thought and or a favorite quote. Anything that you want to share with with our audience?
Speaker: I think I might have said this already, but really... you know, the the best respiratory support isn't always the most sophisticated device. It's the one that everyone knows how to use and use as well um and uses it appropriately. So I think um that's been the focus of all the work don' that um that my research is focusing on is getting people comfortable with these devices so that they're using them well um and within how they're supposed to be used.
Speaker: Perfect. Well, me I want to thank you again for first ah spearheading and working on such a wonderful set of guidelines, which we'll link in the show notes. And I encourage all our listeners to to read because there's a lot there that that has tremendous value for clinicians at the bedside. I also want to thank you for taking the time to talk with us today. I know you're post-call and I hope you get some rest.
Speaker: And I really look forward to meeting you in person and talking with you again on the podcast soon. Thank you. Thank you. It was really nice and speaking with you as well, Sergio. Thank you for listening to Critical Matters, a sound podcast.
Speaker: Make sure to subscribe to Critical Matters on Apple or Google Podcasts and share with your network. Sound's transforming the way critical care is provided in hospitals across the country.
Speaker: To learn more, visit www.soundphysicians.com.
