BreatheTV Episode 1
Dr. Alex Rotta | High Flow Nasal Cannula (HFNC) in Pediatric Critical Care Medicine at Society of Critical Care Medicine (SCCM) 2017 Annual Congress
Chris Walker: Hey, everyone. My name’s Chris Walker, Marketing Manager with Vapotherm, and today we have Dr. Alex Rotta from Rainbow Babies and Children joining us for the first episode of BreatheTV. We’re really excited about the show we have here. I think it’ll bring a lot of value to you in terms of just being able to share experiences and interact about how we’re using high flow nasal cannula, as well as other noninvasive respiratory modalities for pediatric and neonatal populations.
Without further ado, I’ll let Dr. Alex Rotta introduce himself and give a little bit of a background of who he is and how he got into the medicine and pediatric field.
Dr. Rotta: Thank you for having me, Chris. I am currently the chief of pediatric critical care and medicine at Rainbow Babies and Children’s Hospital. I’m also the interim chief of pediatric emergency medicine at Rainbow and a professor of pediatrics at Case Western Reserve University, also in Cleveland, Ohio. I’ve been practicing with Vapotherm for over 15 years and have really learned to trust the technology. It’s a pleasure to be here in Honolulu with you. It’s great to be talking about the high flow technology.
Chris Walker: Sure, and so I’m looking forward to seeing the presentation on one of the abstracts you’re doing on Tuesday, as well. You presented one today, this morning. Could you tell us a little bit about the research you’re doing, and some of the conclusions you’re drawing, and how it’s impacting your practice?
Dr. Rotta: Sure. I’m here, among other things, to support many of our fellows. I am fortunate to work with a great group of people, and many of them are studying respiratory failure and high flow technologies.
I wanted to highlight two studies, one that was presented earlier today, which is a physiologic study of using high flow in a model of airway obstruction. What we’ve done is, through 3D printing technology, we have an adult airway. To that airway, we impose different resistors, a mild, a moderate, and a severe airway obstruction resistor. Then we have a healthy volunteer breathing through that contraption with an esophageal balloon to measure intrathoracic pressure swings.
What we do is, we apply high flow at 10 liters, 20 liters, or 40 liters while breathing these different resistors, and then we can measure the intrathoracic pressure changes and a dyspnea score. What we were trying to show was how does high flow contribute to the decrease in work of breathing that you see in a model of airway obstruction. What we saw was that incrementally, as you increase flow from 10, 20, and 40 liters per minute, there was a significant decrease in work of breathing, that when you’re breathing air or oxygen.
We then added helium to the system, and the results were even more striking. Within just one or two breaths, it was very obvious that the intrathoracic pressure swings were much attenuated, and the dyspnea score was significantly lower.
This provides data to substantiate something that we knew all along, which is that high flow lowers your work of breathing. It makes it more comfortable, and the addition of helium to the gas mixture facilitates breathing through an obstruction. We knew that, since we use high flow to deliver helium to our smaller patients with post extubation stridor, or airway malformations, with great results. Now we have physiologic data to substantiate that.
To deliver helium, our prior alternatives were to use a tight fitting mask, or place the patient inside of a helium box, both of which are quite uncomfortable and claustrophobic to a small patient. Now having the ability to deliver heliox safely through a high flow device is just something that is a game changer for us. We’ve been very happy with the clinical results, and now we have the physiological experiment to substantiate them.
The second abstract that I wanted to discuss today is something that we’ll be presenting the day after tomorrow. It is a study looking at a very large national sample of infants with bronchiolitis, so children younger than two years of age admitted to intensive care units with bronchiolitis, viral bronchiolitis. We then looked at what type of support modality these patients received, patients who received high flow therapy compared to patients who received CPAP or BiPAP.
We then followed those patients on the database and saw that patients who received high flow cannula had about half the chance of requiring intubation and mechanical ventilation, compared to patients who received CPAP or BiPAP. We then did multiple corrections for co-morbidities and risk factors, including the pediatric index of mortality. After those corrections, a multi-variable logistic regression showed that patients who received high flow therapy had a significantly lower length of stay, compared to those who received noninvasive mechanical ventilation, such as CPAP or BiPAP, and also had a lower mortality.
There is a pretty strong association between high flow therapy and good prognosis in those patients with bronchiolitis. We now need to conduct perspective studies to see what is the cause and effect involved in this association. Right now we can only claim an association, but not cause and effect. Those are pretty powerful data in a very large sample of over 6,000 patients, so we’re very excited about those data.
Chris Walker: Sure, and that’s a really nice segway, because I suppose that bronchiolitis patients have really been where our therapy has fit in the most. Then it’s kind of expanded from there, so could you tell me a little bit about how you’re managing bronchiolitis patients at Rainbow Babies?
Dr. Rotta: Sure. I spend most of my time in intensive care unit. That is the ideal place to study high flow therapy, or apply that to the pediatric patients. For instance, this time of the year, winter in the Northern Hemisphere, we have an abundance of patients with bronchiolitis, viral bronchiolitis, caused by respiratory syncytial virus, or other viruses. That is by far the most common cause of hospital admission for children. It’s a very rich patient sample.
Bronchiolitis is such an intriguing disease, because it’s so abundant and pervasive in pediatrics, and yet, there is no specific treatment for it. When a patient presents with bronchiolitis, perhaps the most powerful thing you can do is clear their airway. Suctioning and rinsing their nasal cavity often results in some improvement. But the patients that come to the intensive care unit are usually the sicker ones, those who already failed that. We try bronchodilators, such as Albuterol, because some of those patients respond, like the asthmatic patient. Yet, many of them don’t, and really there is no treatment beyond that. All you can do is try to support that patient’s work of breathing.
That’s when high flow therapy becomes so important. It has been our observation and the observation of many other services that the initiation of high flow therapy in patients with critical bronchiolitis is a powerful tool. It often avoids the need for escalation of support, such as intubation and mechanical ventilation. We have seen a significant decrease over the years of the need for mechanical ventilation in our unit and units that use high flow therapy.
Historically, if you look at historical samples of bronchiolitis from 10 years ago, as many as 30% of those patients who were admitted to the ICU required mechanical ventilation. Nowadays, that percentage is about 10%, so a significant reduction in a very invasive and potentially morbid therapy, which is intubation and mechanical ventilation can be avoided by the use of high flow therapy.
Chris Walker: There’s been, I think it was a retrospective study, that showed that intervention early in bronchiolitis, specifically in the emergency department, resulted in significantly less intubations. Could you tell me a little bit? Are you using high flow in the emergency department, or is it just secluded to the PICU right now at Rainbow?
Dr. Rotta: High flow started, as in many places, in the PICU at Rainbow. What we noticed is that when we look at our data, and we look at data from other institutions, starting high flow in a pediatric ICU, especially if we’re talking about bronchiolitis, lowered the intubation rate from a historical around 30% to somewhere around 10%, so something very remarkable. Patients that can get to the ICU and get put on high flow see that benefit. What we started to see is that once we now rarely intubate patients in the ICU, we started to still get patients that are intubated, but they’re intubated pre-ICU, so they get intubated on transport, at the referring institutions, or in the emergency department. The natural transition was to say we’ve already worked this in the ICU, so let’s take this down to the emergency department and see if we can, by using there, avoid intubation on those patients that were coming to us already intubated.
We don’t have our own data to support that. What I can tell you is that we’ve had many patients, who I’m convinced would have gotten intubated in the emergency department, and yet get started on high flow, and come to us in the ICU, and we can then avoid intubation.
There are just a couple of studies looking at that, and none of them in pediatrics are in randomized controlled trials. There’s an interesting study out of Massachusetts looking at three different cohorts in the emergency department, one where high flow was not available, and they had a high intubation rate. One where high flow was available, but people really hadn’t figured out how to use it yet. That was a transitional zone. There was really not much signal there. Then there was a time where, which is a more contemporary APOC, where people had high flow available, and knew how to use it, and had protocols. What they saw was the same thing that we saw in intensive care unit, that by using high flow and using it early and well, they were avoiding intubation on those patients.
We have now very aggressively moved high flow to our emergency department at Rainbow, and we’ve seen that happen throughout the country.
Chris Walker: One thing that I’m always curious about is process. Making that transition from the ICU to the ED is really very much so an organizational change. I was hoping you could just talk me through the process that you went through when making that transition or extension.
Dr. Rotta: Sure. I think in our particular instance, this was a little bit easier, because I have operational oversight of both units, the ICU and the emergency department. It was easy for me to make a compelling case that, here, this is what happened to our ICU, and this is the benefit we’ve reaped from this technology, and this is how far we’ve come. I didn’t really have to convince too many people to allow me to move that into the emergency department, because I control the operation. I’m very fortunate we’ve done that.
I can tell you that there was some initial reluctance in bringing the high flow technology to the emergency department, perhaps because my colleagues in the emergency department thought that that was more of a destination, a medium, long term therapy, and that perhaps those patients were going to sit in the emergency department for a long time, as we tried to decide where they were going. Nothing could be farther from the truth. We essentially moved the technology down there to be able to be rapidly deployed when a patient comes in, in trouble, try to avoid intubation so that it can give us a chance not to have to intubate a patient up in the ICU.
We’ve been doing this for a couple of years now, and after that initial resistance, I can you that if just by magic, one said that you cannot do high flow in the emergency department anymore, I’m pretty sure I’ll have a revolt in my hands. That’s how ingrained that technique has become within our institution. This is not unique. I can think of several accounts of other institutions that have followed the same path, first in the ICU or neonatal unit, and then once the word gets out that you’re not intubating all those patients anymore, then everyone wants a piece of that type of technology. It’s been rewarding to see that.
Chris Walker: Sure. When we talk about bronchiolitis patients in the emergency department, I’ve seen some data that shows just basically what markers you would look for to see if the patient was going to respond. I don’t know if you could elaborate, based on your experience on what clinicians should look for, and then how they should dictate medical decisions based on that.
Dr. Rotta: Sure. Whether you start high flow in the ICU or in the emergency department, you’re looking for markers of clinical response, and those happen pretty quickly. You’ll place a child with bronchiolitis on high flow, and within minutes, you’ll see respiratory rates trying to slow down, nasal flaring starts to go away, the intercostal retractions. Having been the recipient of high flow myself during experimental conditions, I can tell you that even if I was blindfolded and in completely blinded conditions, I could tell immediately when high flow was started, just based on the work of breathing. We see that with children.
Within 30 to 60 minutes, you will see a decrease in heart rate and a decrease in respiratory rate, an improvement in oxygen saturation, and those are very good markers that you have a responder. Interestingly, patients who do not lower their respiratory rates, who do not lower their work of breathing or heart rate within 60 minutes, are much more likely to require escalation to another mode of support, such as bi-level ventilation, BiPAP, or invasive mechanical ventilation.
Chris Walker: I wanted to switch gears for a minute. We’ve talked a lot about bronchiolitis. Now I wanted to open it up to you to talk about other patient populations that you use high flow nasal cannula to manage. Just tell me about your experience with that.
Dr. Rotta: There is a wide array of patients that we use high flow in the ICU for. Aside from bronchiolitis patients, which there is not a day in our ICU that we don’t have a few high flow circuits running. Currently, since this is now the winter in the Northern Hemisphere, we have multiple machines, mostly occupying patients with bronchiolitis.
For other patients, patients with pneumonia, acute hypoxemic respiratory failure, or ARDS, we really have transitioned use of high flow for those patients with the more mild or moderate disease, and I am convinced, although we haven’t looked at that specific data for our institution right now, I am convinced that we’ve seen a decrease in need for intubation in patients with severe pneumonia or ARDS.
Those data are available. They are available in adult samples, and results are quite striking. We mirror that from the adult populations, where high flow not only showed to be at least equivalent to noninvasive ventilation. But there’s a study that shows that it actually lowers mortality, compared to noninvasive ventilation, which is a trend that we picked up in our study that we just discussed a few moments ago.
We have pretty good grounds to use high flow in hypoxemic respiratory failure, pneumonia, ARDS. We also use high flow quite frequently on patients we experience significant respiratory distress after extubation. Patients who went to mechanical ventilation and have near resolution of their disease and are now ready to be extubated, some of those patients will have residual respiratory embarrassment, such as post extubation stridor or atelectasis, or just manifestation of their primary lung disease. In those patients, we’ve used high flow with great success, as well.
The other population that has been increasing in our practice is the use of high flow in patients with critical asthma. Patients that come to the intensive care unit with severe asthma attacks, or formally known as status asthmaticus, those patients seem to benefit, as well. We are late adopters of using high flow in that population, because up to very recently, we did not have a great way of providing the respiratory support with the high flow cannula and providing nebulizations with Albuterol, which is one of the pillars of therapy for those patients.
Now, Vapotherm has partnered with Aerogen and has the Aerogen adapter, so we can use an ultrasound piezoelectric type nebulizer that does not add any flow to the circuit and therefore doesn’t cause significant rainout. We’ve been pretty successful in supporting patients on continuous Albuterol therapy receiving high flow cannula.
Chris Walker: Do you just use continuous in the PICU or anywhere outside the PICU?
Dr. Rotta: In our hospital, we only do continuous Albuterol in the emergency department or in the PICU. Both settings can be adapted to be used through high flow cannula. Continuous Albuterol is sort of a fringe therapy. There is nothing, other than resource allocation, that shows that continuous Albuterol is significantly better than intermittent dose of Albuterol. Whether you choose to use it intermittently, say four or five doses in an hour, or continuous Albuterol, it’s really just an institutional preference. But it’s a population that we really have started using more, now that we have a good viable option for nebulization.
Chris Walker: Absolutely. One thing that I’d like to dive into for a moment is use of high flow nasal cannula in the cardiac ICU, specifically the post extubation, or post-surgery. I just wanted to see, do you use high flow in the cardiac ICU, and if so, how?
Dr. Rotta: We use high flow in our cardiac ICU, and I used high flow in my previous institution, also in the cardiac ICU. I think it’s a great place to use that technology. A patient that comes to a cardiac ICU, especially those post cardiac surgery, are usually patients who were reasonably well, and then they had surgery, which is often very complex. It often involves them coming back intubated, but the course of mechanical ventilation in those patients is just as long as you need to support them. It’s not until the resolution of a respiratory disease, for instance. Many of those patients will be extubated within six to 24 hours after surgery.
It is the impetus to try to get them off conventional ventilation quickly that creates a niche for high flow. Once we extubate those patients, we often extubate them directly to high flow for various reasons. One is, we are providing a very predictable fraction of inspired oxygen, which plays a role in certain cardiac repairs. Two, we’re providing very conditioned medical grade gas that is at the perfect temperature and perfect humidity, so it doesn’t create any desiccation or irritation of the area at high flow. Just by the general principle of high flow of washing out that space, we can achieve the same minute ventilation without having to work too hard for that, meaning the device clears CO2, not necessarily dependent on the patient’s imposement of ventilation. Work of breathing is more relaxed.
But most importantly, a patient in the cardiac ICU generally has a cardiac problem. Deep spontaneous negative inspiration is detrimental to the left ventricle. When you take a very deep inspiration, you’re increasing the afterload of the left ventricle. You’re making the heart work harder by taking a deep breath, especially against the resistance, and especially after you extubate someone. It is not uncommon for a patient that has borderline cardiac function to do well during mechanical ventilation. When you extubate, just the additional work of breathing, and the negative effect of spontaneous inspiration on the left ventricle, will be sufficient to cause pulmonary edema, and heart failure, and the need for reintubation. High-flow really helps us bridge that vulnerable period and decrease the intrathoracic negative swing that would negatively affect the left ventricle. That’s called, we just attenuate the decrease in afterload that would happen.
Chris Walker: Then how about for early mobilization post-surgery, I know that’s quite important. Do you do that at Rainbow?
Dr. Rotta: We do, and the ability to have a patient attached to what really amounts to a nasal cannula at the patient interface, and that can be wheeled around. We can have patients up and moving on high flow, and that is that great deal of what’s needed for the recovery, getting patients up, out of bed, walking around, and moving. It’s one step closer to being out of the ICU.
Chris Walker: I’ve spent quite a bit of time at children’s hospitals the past year, and one thing that I continue to see is challenges with PICU capacity, specifically at this time of year. I was wondering if you had any advice or things to talk through about your experience dealing with that challenge, and then how you’ve tried to address it.
Dr. Rotta: Sure. I’ll tell you what prevented our institution, where we have a limited amount of beds in the ICU, and we would like to never have to turn a patient away. There are many times, especially this time of the year, where we are full to capacity, and yet we’re getting calls from smaller hospitals or community hospitals trying to place their patients in our ICU. We very quickly have to survey which patients are the most stable ones and who can leave the ICU. Sometimes there is no one who can actually leave the ICU.
What we’ve done is taken advantage of physical space that is right adjacent to our ICU, and it’s a step-down unit. We can transition patients on high flow to that physical space, still under care of ICU physicians, but those are patients that have already responded to high flow. They’re in a lower risk category and those who have shown a greater level of comfort with the high flow therapy. Those patients can then be selected to be moved to this adjacent space and free up space to a more critically ill patient, without having to ration care.
Then so we are now moving high flow out of the ICU into step-down units. There are many hospitals that have done so. We have been late adopters of that. Our hospital has a great intolerance to risk and failure, but out of necessity, we’ve done that with very good results. Hospitals can look into cohorted physical space, where there is a respiratory expertise and proximity to an intensive care unit. The proper monitoring in our step-down unit doubles as an ICU. You can move high flow to an adjacent space very safely and free up space in the ICU.
Chris Walker: Alex, this has been amazing. I want to thank you for joining us today. I think it’s been really great. Maybe this is something that we do on a more frequent basis, like every six months, just check in and see what research is going on. Maybe you have some new things to present, or maybe we connect again at this time next year for FCCN, if you’ll be there.
Dr. Rotta: Sure.
Chris Walker: Do you know where the conference is located?
Dr. Rotta: The conference in San Antonio next year. I think it is, and I might be wrong, as I often am.
Chris Walker: Okay, well thank you again, a joy to see you.