BreatheTV Episode 27
No Mask. No Problem | A Webinar with Michael Bublewicz, MD
Jeff Maglin: It is now my pleasure to introduce our speaker, Dr. Michael Bublewicz. Dr. Bublewicz has comprehensive healthcare administration experience as a medical executive and emergency medicine physician responsible for management and operations of 20 emergency departments. He also serves on faculty at the McGovern Medical School, UT Health, the University of Texas Health Science Center at Houston. Dr. Bublewicz has used Vapotherm in his facilities as a part of a randomized clinical trial and in everyday clinical practice for greater than three years.
He’s an author of three studies, two related to Vapotherm Hi-VNI technology in an emergency department, including ‘High Velocity Nasal Insufﬂation Compared to Non-invasive Positive Pressure Ventilation in the Treatment of Respiratory Failure in the Emergency Department: A Randomized Clinical Trial,’ published in the Annals of Emergency Medicine in 2018. Dr. Bublewicz can speak to the acquisition, adoption, and the potential clinical and economic impact of the technology from the point of view of an ED medical director. I will now hand the controls over to Dr. Bublewicz.
Michael Bublewicz: Well, Jeff, thank you very much for the introduction, and thank you all for letting me participate in this. Hopefully everybody can hear me okay, if not Jeff will let me know. We did our testing prior to going live. What I’m gonna present to you guys today is the concept of: No mask, no problem, high velocity nasal insufflation, a viable alternative to NIPPV.
As Jeff stated I’ve been using this product for several years. I was introduced to it first, five years ago at my institution. It was very novel, very different, something I hadn’t seen before. And it created some interest. As Jeff mentioned, I am a paid consultant for Vapotherm. I was one of the study authors, and Vapotherm compensated me for my time to provide this explanation and this teaching to you guys.
The disclaimer, Vapotherm’s Hi-VNI technology is a tool for treating respiratory distress. The following slides convey study results in relation to the use of Hi-VNI technology, but individual results may vary. Vapotherm does not practice medicine or provide medical services or advice. Any clinical recommendations provided herein are solely those of the speaker, myself. Practitioners should refer to the full indications for use and operating instructions of any products referenced before use.
Okay, so today’s learning objectives, what I’ll do is I’ll describe to you guys the mechanisms of action of Hi-VNI, or HVNI, to show how HVNI provides non-invasive ventilatory support into spontaneously breathing patients. We’ll allow you to understand the correct cannula to patient interface for safe and optimal use of HVNI. We’ll review the data from a multi-center randomized controlled trial, which demonstrates HVNI is non-inferior to NiPPV in the management of the undifferentiated respiratory distress patients in the ED.
As a practicing ED doc, in fact I have a shift tomorrow, I practice a couple days a week, we see a lot of respiratory distress patients. It’s one of the top five causes for admission into the hospital, or presentation to the ED, for that matter, and we are flowing into respiratory season. So, historically, we’ve been a little bit limited on the front lines as to what we have in our arsenal to manage these patients.
We have the traditional oxygen therapy via nasal cannula and mask, non re-breather, we’ve had NiPPV or some form of BiPAP, CPAP for decades. And then really, intubation has been the go-to for these patients that are failed alternative therapies and the inherent risks associated with that population. But really, beyond that, we have not had much until recently. High velocity nasal insufflation therapy is FDA approved as a unique category of non-invasive ventilation for the spontaneously breathing patient.
We’ll go over some of the keys to why this technology works, but it delivers high velocity via a flow … Via a small-bore nasal cannula system. So, it’s important to note that the primary mechanism of action for HVNI is not through the generation of CPAP, and we’ll go through several slides detailing the mechanics behind it. HVNI mechanisms of action, HVNI is using flow characteristics from a nasal cannula with optimally conditioned respiratory gas, to accomplish two things: Inhalation, approach a patient’s peak inspiratory flow so that they inspire to deliver gas mixture without the dilution effects from the CO2. And on exhalation, providing adequate flow, for if it’s to purge the upper airway dead spaces of CO2, effectively replacing the end-expiratory carbon dioxide with the conditioned delivered gas.
You’ll notice the anatomy is illustrated on the right. But, during HVNI therapy, the end- expiratory purge both eliminates the end-expired CO2 that gets typically trapped in the end-chemical dead spaces of the upper airways … I’ll have a few graphics that represent that in a few slides from now. And, functionally it decreases that anatomical dead space, effectively turning it into a reservoir of conditioned gas, allowing the patient to actually breathe from the oral pharynx instead of breathing through the oral pharynx. We have a nice graphic representation coming up of that.
Additionally, a greater important component are humidification, so providing the optimal humidified environment to allow the mucociliary function to be maintained within the airways is critical. Actually warm gas flow decreases inspiratory resistance. There’s a little distending pressure, but this is an open system in that the primary mechanism by which it works.
This slide represents a bit of a review of flow and velocity, and it’s important to spend a little bit of time going over this and we’ll have this represented in a few components, a few portions of this presentation because when we’re looking at flow and velocity, velocity is a constant flow a constant volume of flow that varies inversely with the cross-sectional diameter of the tube and effectively that means you can get a higher velocity through a smaller diameter of tube, and that’s effectively characterized here. So, for a flow rate of five liters per minute held constant the velocity and the larger bore tube is represented here at 16 centimeters per second. When you decrease that tube the diameter of that tube, the velocity increases proportionately as well. That’s important to know in the concept of this product specifically and why the smaller bore nasal cannulas are used intentionally to provide this effect.
So, when comparing velocity against the small bore and the large bore tube, really for any given flow rate, the given flow rate of the 40 liters per minute, the large bore tube is nowhere near as fast as the small prong nasal cannulas there. Really, you’d have to follow this curve out up to I think the numbers are 180 liters per minute of flow to approach that velocity of the small prong nasal cannula. Just to let you know Vapotherm does not have a large bore cannula product that was studied in this aspect, so this is their small bore product.
Computational fluid dynamic modeling, you can really see how that high velocity impacts the flow in the what is to represent the anatomical dead space here. So when, to orient you, so the warmer colors here, the red, the yellow, the orange, that is a slower flow. The cooler colors is a higher travel time and a higher flow. What you’ll see, the more red, the more red, the more yellow, the larger bore cannula confirms that the molecules are spending more time in the airway and therefore take a longer time to flush out. When you talk about a patient in respiratory distress, it’s very critical as the respiratory rate increases, you have to be very efficient in how you exchange gas. You don’t have the time for the gas to travel very slowly.
So, this graphic represents spontaneous breathing. What you’ll see is that on inspiration fresh gas inspired, exhalation which you’ll notice is on the inspiration phrasing, when you take the breath in you’ve got a mixture of CO2 rich gas that is pooled in the upper airways, being inspired with the fresh gas coming in. When you look at a system that purges the HVNI system it purges the anatomical dead space, really minimizing the amount of CO2 that resides in a anatomical upper airway dead space, you can see how more efficiently you can get the enriched high-quality gas to the point of alveolar exchange through the lungs. Having gone over that, so the mechanistic difference between HVNI and NIPPV is, you can represent it mathematically and this is the concept of alveolar ventilation at the level anatomically where gas is exchanged. So, minute ventilation is the volume of air that flows in and out of the lungs in a minute. The alveolar ventilation is the volume of air that flows into and out of the alveolar space that is available for gas exchange. So, when, sorry so, we’ll go on to the next slide, here we go. So, efficiency, so alveolar ventilation efficiency is what we’re trying to get to here.
For any given alveolar ventilation, so given that, that the alveolar ventilation is the inspired volume less the dead space times respiratory rate, okay so for a given constant alveolar ventilation, when we decrease the amount of dead space, for the same alveolar ventilation you can achieve it by decreasing the work of breathing. That can be represented in smaller tidal volumes, decreased respiratory rate or some combination of both and that’s where you visibly will see the patient’s work of breathing decrease, as that respiratory rate decreases in here. The breath, each breath, becomes much more efficient, they do not quite have, they will not have to breath quite as quickly and you see that play out clinically for those that have had experience with this product.
The key to that is to, for the patients that come in, in extremis, that you get adequate flow rates, you get really high flow rates started on them very quickly to maximize the effect of your intervention and we’ll go into that as well.
So, two keys to the correct use of Hi-VNI and its the content I alluded to in the previous slide, that you really do have to use supraphysiologic flow rates. The high flow, high velocity, the quick air movement as we exemplified in one of the previous slides with the air exchange model. That’s a significant component, getting that carbon dioxide washed out, improving the quality and condition of the air that resides in that upper anatomical dead space makes a massive difference. In order for that to work this has to be maintained as an open system and this is why the nasal cannula size is critically important. Vapotherm does offer a wide range of nasal cannula dilators that we’ll show you guys. The key is to maintain enough space even with the patient’s mouth being open to be able to allow that gas to exchange and flow out.
The ratio that is recommended is the nasal cannula to nares ratio of about 0.5, so you do not want to occlude more than 50 percent of the nares with the nasal cannula to allow that flow from the anatomical dead space. For the same reason the patient’s mouth being open would be optimal, that’s a quicker area of less resistance, you can allow more efficient exchange of that flow.
Here’s an example of the nasal at the nares level of how that would look. A simulated cannula, about fifty percent of the diameter of the nares to allow even with the patient’s mouth closed that system to be open: A. To exchange gas and really get the benefit of a flushing of that anatomical dead space but be enough to minimize the chance of barotrauma. A larger cannula would be more restrictive in allowing that free flow of gas.
I’ll pause here for a second so everybody can come and sit down.
There are a wide variety of cannula used for our study. We used the adult cannula which was appropriate size for most individuals, but there is quite a variety and even a single prong cannula as well, and the single prongs you certainly would not occlude more than fifty percent of the nares so, such that one is not even introduced with a nasal cannula prong.
In the HVNI continuum of care, in going back to the undifferentiated respiratory distress patients and sort of the levels of acuity. You’ve got the ones that are mild respiratory distress, moderate and very severe, and sort of every gradient in between. In the past for the very mild patients often supplemental to use a cannula and not a breather, a mask, whatever the case may be for hypoxemia respiratory failure often did the trick. If you had ventilatory issues or severe distress then really the only thing we had short of intubation was a NIPPV. Now Hi-VNI therapy kind of fills that window, where you can really address a lot of issues in the mild to moderate respiratory distress patient before needing to progress to mechanical ventilation or even a trial of NIPPV mask and a different system, so we’ll keep that.
What we found and I’ll go into this whole … we get into the studies. We’re looking at these patients coming in and the KMP actions of care, it wasn’t until I started seeing this product used that I realized in a practical sense that there was another option short of using the mask on a patient for quite uncomfortable appearing patients and we’ll go over that a little bit later. So, typical flow rates, okay so one of the tenets was you have to start at a very high flow rate to get the velocity you need to flush that anatomical dead space as quickly and efficiently as possible given the amount of respiratory distress. Usually these patients come in with very high respiratory rates, so you’ve got to start efficiently getting that conditioned air into the right space. You can make the most out of every one of those very quick and inefficient breaths. In adults we typically start in the twenty-five, thirty-five, forty range.
It’s a technology where we start high and go low, and for the physicians in a room, it’s very akin to a CHF exacerbation, where the patient is extremely hyper tensing, and so nitroglycerin at an extremely high rate and then titrate downward because you really need that initial high concentration of your treatment effect to make the most out of that patient care experience. In a pediatric population anywhere in that eight to fifteen depending on the size of the kiddos. I use it far less frequently in pediatrics, we have a separate pediatric emergency department, I don’t typically pull shifts there, the neo-nate group is not a group that I practice in so it’s mostly … my experience has been with the adult population.
The other considerations, you know, the issues starting with the very high flows, you’ve got to select the right nasal cannula. If you do have a small adult they do make a small adult/ pediatric sized cannula for that population, let’s be cognizant of anyone with small features that you definitely don’t want to occlude more than 50 percent of the nares to allow for the most efficient exchange of gas. That flow dynamic, the rate and the flush rate, that’s independent of the FiO2, so we’re really creating the efficiency, we want to get that dead space covered outside the reservoir cleared. Then gas conditioning, both for comfort and for efficacy. It’s got to be humid and it’s got to be warm. It could be quite dangerous to have a cool high flow dry gas going into these patients, so what the heating does is achieve the optimal humidity and warmth temperature very very rapidly.
Kind of on that point, so in order to deliver the high velocity high flow rates comfortably and safely. You really do need a window of that optimal humidity and that has been studied and proven, where that is, so you have to … the mucosal function is directly related to the humidity of the expired air in a mix does really make a massive difference. So, when sort of summarizing the constellation of mechanisms, with this technology a washout of the nasopharyngeal dead space, there’s supporting distensible nasopharyngeal anatomy, so during inspiration adequate flows to meet inspiratory flow demand, so you’re getting enough of that conditioned gas to where it needs to be in an efficient quick manner, so warm humidified gas to the conducting air ways improves conduction as well as the pulmonary compliance, it’s got to be the right temperature, it’s got to be the right humidity. And also, the decrease the metabolic load on the patient. There is a modest distension pressure, that you can feel it having put on this product with a closed mouth a little bit. Patients depending on the reason why they’re in respiratory distress, that can help occasionally. We’re not talking about massive pressures here, because there still is an open system and that pop up value is that 50 percent availability of the nares diameter. Athens, one of the locations, one of the sites of the study, that we’re going to reference later on in our presentation that’s published on annals, the case study from their site, it’s sort of the quintessential COPD patient. Sixty year old patient, history of COPD comes in the ER, Athens Regional Medical Center. You can insert any hospital, any ED, any medical center and you have especially this time of year looking to see thousands of these patients across all of our practices. Patient’s been intubated in the past month for COPD exacerbation, so a very challenging patient to manage, if this is a bounce back after an intubation, then there are a lot of things that are failed to have you not succeed at home and you have obviously very advanced [inaudible 00:24:27] disease if you require intubation or just waited too long on the exacerbation continuum
The initial assessment tachypnea with nasal flaring, pursed lips, wheezing, wet cough. You can picture this person in your mind, very tachycardic, tachypneic, so at this institution Bi-Pap was ordered, but it was not initiated, they threw on Hi-VNI technology instead. They went at 25 liters a minute with an FiO2 of 60. Not a terribly high flow rate and this leads to his initial presenting, blood gas and his hemodynamic parameters. Heart rate of 124, respiratory rate of 36, paints a picture of a very very sick person. Ph 7.28, PaCO2 of 74, a lot of attention, O2 sat okay for this person, but they’re working to get there.
The patient arrived at 6:08, 6:29 they were able to get the Hi-VNI, the initial blood gas drawn, 6:30 that was the one that we viewed earlier, and if we go through we start to see the timeline of progression here, so less than 10 minutes later you see a respiratory rate really, really decrease from 6:30 to 6:43, I mean going from 36 to 27 and then subsequently down to low 20s, mid 20s and that’s a visible improvement. When somebody is breathing 36 times a minute and you start to see them breath in the 20s, it’s a noticeable impact on their perceived clinical progression. Blood gas about 45 minutes later on the therapy really improved respiratory acidosis.
Clinically this is what you’ll see, this will make you very comfortable. It’s that respiratory rate, that work of breathing, you know the retraction, its dose components that as a bedside clinician, a physician, a nurse, a respiratory therapist, when you’re working with a patient and you start to see improvement prior to getting your … some objective data points like bp, blood gas, that’s where you really start to see the true benefit and the impact of this technology.
I’ll pause there for a quick second okay. What we’ll go into next and actually moving along pretty nicely here, so we’ll have plenty of time for Q and A. What we’ll go into next is the study, that Jeff was referencing. So, got a colleague and a good friend of mine Pardeep Doshi. He’s quadruple boarded emergency medicine, pulmonary critical care medicine, neuro-critical care, just a naturally curious guy who is very familiar with the technology in the ICU setting, de-escalation therapy post intubation and was wondering about the use of the acute ED setting. Again as a practicing ED doc he had not had a ton of resources in his arsenal to achieve effective management of somebody’s patient.
This was the first Phenrex controlled trial, looking at Hi-VNI to include the Undifferentiated Respiratory Failure, including the Hypercapnia. So pretty much it means the [inaudible 00:28:35] were studied and the hypoxic respiratory failure, pretty sure not the hypercapnic cases. All you have to do is look at those patients that we have coming in that are really in respiratory distress. Could this be used as well in addition to the NIPPV and would it have been any worse than that?
The hypothesis/ methods where the HVNI was not inferior to NIPPV in the treatment of the undifferentiated respiratory failure in patients. Sorry guys can you hear me okay?
Speaker 3: Yes.
Speaker 4: Yes I can.
Michael Bublewicz: Okay sir. Okay, a little microphone issue. Okay so sorry about that. Okay so, we hypothesized that HVNI was not inferior to NIPPV in the treatment of these patients. The new design of the prospective multi-center randomized control trial using comparing the two methods of ventilatory support, so the NIPPV and HVNI. So we used 3 community sites and 2 academic medical centers. We wanted to make sure it was as generalizable a variety of geographies within the country, one other state to another state, different times of the year and different settings. You know, those with resonance and a lot of tertiary quaternary resources and those with just average community practice sites, where you may not have the [inaudible 00:30:03] resources.
So inclusion criteria, so we looked at adult patients in acute respiratory failure, presenting to the ED, requiring escalation to NIPPV. Effectively, what I told the docs in the way I practice when I was on shift, is if you see anybody in respiratory distress that’s severe enough where you’re considering NIPPV randomize them and then let’s see if there’s a benefit for this therapy. We did want to be practical in our [inaudible 00:30:34] this is a group that you think has an acutely reversible cause of respiratory distress. Those that are critically ill and in cardio-pulmonary arrest weren’t eligible. This isn’t really targeting the patients on hospice and the low life expectancy advance cancer in this group. From the intervention standpoint those with severely depressed mental status that wouldn’t typically be eligible NIPPV anyway due to that point we excluded, those with a stroke, those with a STEMI that had other pressing matters that needed intervention on than a randomized CO2.
And really, anybody at risk for aspiration too, so again when we’re looking at the contraindications for NIPPV the practical context is the person that’s in respiratory distress that you’re thinking about Bi-Pap and could handle Bi-Pap that could prove that we ended up randomizing. The primary end point that we were measuring was treatment failure and the way we define failure was sort of two ways. Most importantly was the failure requiring intubation and mechanical ventilation. That is the extreme end of the spectrum that we were trying to avoid for a variety of reasons. But also, the other component of the study, is we measure a failure as a cross over from the primary arm of assignment. Everybody through this study designed because this was a novel product in the sense in this application we really needed to leave room for the treating team to treat patients and the interests that they thought was best and in some context there was a preference for NIPPV even for the patients that were initially randomized to the Hi-VNI.
For the endpoints we measured a litany of data points, including the physiologic parameters with vital signs and metabolic parameters as well as some subjective components. How did the patient feel about this? How comfortable was it? How did they tolerate it? What was the physician and treating teams perception of the efficacy of the therapy as well? Then we looked at length of stay, disposition, location, etc. Really what we were trying to prove or at least observe is that is there any difference in how many people we have to intubate.
So, we randomized these patients, we monitored them for 72 hours post randomization, so it was a thick enough cohort that had a length of stay in a hospital for a decent amount of time. The patients were randomized a little bit differently in the sense that they’d have the limitation of day time hour randomization for certain locations, where we only had the extra RTV source to fit at the bedside of that patient for the first 3 to 4 hours of their therapy, while they were drawing blood gases and monitoring them to be able to do this. They were sort of constrained by the limits of what resources we have available at the hospital, but during that time period anybody that met inclusion criteria was able to be randomized, was randomized.
We calculated the sample size of 204 needed, we would end up having 100 NIPPV and 104 in our HVNI group and that was using sort of the literatures published data of around intubation rates of around 16 percent or so. The non-inferiority margin includes the broad variability in intubation rates within the NIPPV intubation rates. Intubation rates varied quite drastically by some of this literature, so we had to pick a number, 15 percent for intubation and 20 percent for all-cause arm failure including subjective crossover. Those are the numbers that statisticians helped us decide.
Patient characteristics, they were really randomized well, no significant difference between gender, age. We have the patients specific characteristics, mean age in the 60s, which you’d expect. We did have some southern states and the mean BMI was relatively high, which was a little bit surprising, but respiratory failure and the undifferentiated states is come to by a lot of comorbidities. Apache scoring again, both groups were equally matched for just how sick they were in general. And then again, it was the undifferentiated respiratory distress patients, some you suspected were very clearly, you look like a COPD patient, you’ve got the barrel chest, you’re brachectic and you were smoking a cigarette on the way in to the ED, then sure. Other patients were much more difficult to differentiate or they had mixed disorders too. Very often severe cardio-vascular disease accompanies respiratory disease and this is not a typical, so the conditions preventing conditions were well matched among the two groups as well. Patient characteristics, 33 percent were the COPD/ Hypercapnia group, 20 percent were CHF, 15 to 20 percent were pneumonia, 28 percent were that hypoxic mixed respiratory failure group and that’s the graphic representing the HVNI randomized cohort and the distribution. Primary outcomes, HVNI was non-inferior to NIPPV for failure to intubate, so the intubation rates for HVNI were in the 7 percent range and NIPPV were in the 13 percent range, so a risk difference of about 6 percent. They do have overlapping comparables, but you know we were, as well matched as the patients were, we were pleasantly surprised to see that the intubation rates were not higher in the HVNI group relative to the NIPPV group. The primary outcomes as we discussed with the intubation rates, it was HVNI was less than NIPPV and definitely not worse. The other primary outcome on a crossover so HVNI was non-inferior to NIPPV for the all-cause on failure in crossing over to the other arm. HVNI crossover at 26 percent versus NIPPV at 17 percent. It was actually interesting. Not terribly surprised, just because of the study design from the patient safety standpoint.
We needed loud very easy crossover and a lot of the patients to stay in the study to really see what happens to them and I wasn’t surprised to see 26 percent or a reasonable size of percentage of patients being crossed over to the NIPPV technology just because that is a more familiar platform for a lot of physicians. This was more so after the patient had been admitted on the in-patient side and again for a variety of reasons, but not significantly different between the two given our samples. The secondary outcomes, the other component to heart rate, respiratory rate, SpO2, PCO2, the BORG score, enough significant difference on any real parameters. When we look at the graph of PCO2 in both the NIPPV and the Hi-VNI group really relatively similar slopes. We’re not talking about patient related outcomes here, we’re talking about physiologic outcomes. But, it does add to the complete understanding of how this technology is used, where it’s effective and physiologically sort of proves the theory as well of ventilatory improvement and ventilatory efficiency.
The physician’s perspective, they seem to favor more the Hi-VNI group. I gotta be honest with you, it’s been several years now of actively using it. It is a more comfortable appearing product. I still use both depending on the circumstance and the immediate need of the patient, or, I don’t know if I should be saying this but we’re sometimes out of Hi-VNI machines, they’re all being used in other parts of the hospital, so we might be left with an NIPPV. But the perception of comfort, a patient’s comfort, I mean it’s just it’s night or day. I don’t know how many times over the years, you have to sit at the patient’s beside when you put them on a Bi-Pap and coach them through it, especially if it’s a person that’s never. That’s novel for some, someone that’s chronic say a chap that comes in once a month every other month, that’s gotten used to this COPD, that’s gotten used to Bi-Pap in the past, those are a little bit easier to coach through, but the novel patient or the one that definitely doesn’t like the suffocating feeling of that mask, that closed system.
This is a great improvement in the perceived, my perception of the comfort the actual comfort. Especially you can speak to me, you can get a history from, you can do an assessment without having the muffled voice. If they have a question they can communicate appropriately. When stable enough they can start taking oral either medications or fluids or whichever it can be. The comfort level is not difficult to see the improvement. Really, monitoring technical complexity, it’s pretty easy to set up. No more difficult than the Bi-Pap. Obviously several limitations in the study. You can’t really blind someone to whether they have a mask or nasal cannula on. The crossover component of it, there was a lot of subjectivity and it will have a terribly comprehensive understanding of what every system the crossover was but it was usually the treating teams preference, so the …
Oh another component, so we used both of the EBGs and ABGs, there is a growing body of literature supporting the validity of venous gas analysis that’s compared to arterial gas analysis. When you’re looking at certain physiologic parameters, so we use both. The initial blood gas was happened to be a venous gas then we just stayed with venous gases throughout the patient’s enrollment period, so we’re comparing like and like. If the initial gas was an arterial gas, then we repeated the arterial gases during the patient’s stay with us. The concluding findings and commentary. High velocity nasal insufflation is non-inferior to noninvasive positive-pressure ventilation for the treatment of undifferentiated respiratory failure in adult patients presenting to the ED. How this is relevant to our clinical practice is it gives us practice in that setting and have those type of population is that high-velocity nasal insufflation may be a reasonable treatment option for those in respiratory distress.
In summary, higher velocity flows at the same volumetric volume is why the Hi-VNI technology is able to flush that extra thoracic dead space more efficiently than large bore systems and allow a patient to breath mixed air versus diluting enriched air with the retained CO2. Flush time is key, okay, that’s what we discussed, the more tachypneic a patient, the higher work, the more respiratory distress they’re in, the shorter the expiratory phase. So you really have to efficient in washing out that carbon dioxide and the high flow, high velocity achieves that very rapid flush.
In order for the dead space purge to occur the system has to be open. The nasal cannula must not occlude more than 50 percent of the nares, this allows the free egress of flow from the system. It’s critical to also avoiding the inadvertent pressure generation that’s a potential for barotrauma. The Doshi et al study published in the annals of 2018 concluded that Hi-VNI nasal insufflation in non-inferior to NIPPV for the treatment of undifferentiated respiratory failure in adult patients presenting to the Emergency Department.
There’s my contact information for those that are interested in from a practical standpoint, as an operational leader within the emergency department in the hospital. Resource innovation is of paramount importance, so any time I can save an intubation, save an ICU bed, save a higher level of care the better off we are with having that resource available for another patient that needs it. I can’t tell you how nice it is to have another option for treating these patients rather than get that suffocating mask.
Jeff Maglin: Thank you Dr. Bublewicz, thank you every one for attending. Again, be on the look out for future webinar invites, as we intend to host at least one of these per month and I hope that everybody has a great Respiratory Care Week.