Transcript

TRANSCRIPT PODCAST: Pediatric Bronchoscopy

TRANSCRIPT PODCAST: Part 1, D217125, 2021-06

TRANSCRIPT PODCAST: Welcome to this Erbe group podcast produced by our Medical insights studio. In today’s episode our Clinical Application Manager Dr. Niklas Froemmel is talking to Dr. Erik Hysinger, Assistant Professor in the Department of Pediatrics at Cincinnati Children’s Hospital. Dr. Hysinger is a board-certified pediatric pulmonologist who has received the Best in Pediatrics award by the American Thoracic Society (ATS).In this episode he will discuss general aspects of bronchoscopic procedures for pediatric patients and use of cryotechnology for treatment of foreign body aspiration and emergent recanalization in critically ill patients.

Niklas: Thank you for accepting the invitation today to talk about a very interesting topic, which is interventional pulmonology in pediatric patients. But before we go into depth about this, please, Erik, would you tell us a little bit more about your person and your way into pediatric bronchoscopy?

Erik: Sure. So for me, my story goes back actually to my residency training. I was very interested in pulmonology and respiratory mechanics and had a lecture to do a procedural month or elected to do a procedural month and went over to the adult hospital at Vanderbilt in Nashville, Tennessee, and did some work with the interventional pulmonology group there. And what I was seeing that they were doing blew my mind. And the ability to be able to see the airway up close and be able to intervene on the airway really piqued my interest and started pursuing that even further in fellowship, doing much more work with pediatrics flexible bronchoscopy. Did some further training with the interventional pulmonology group at the University of Pennsylvania to try to continue to develop that skill set. And then came to Cincinnati Children's Hospital, I guess about five years ago now to continue to do airway work in pediatrics, because Cincinnati is one of the world referral centers for pediatric airway disease. So it's been a lot of fun to see the development of new techniques and new tools to be able to support patients and then trying to adapt that to pediatric uses.

Niklas: When thinking of bronchoscopy in children. What's different to the adult? So which general considerations apply in these very special kind of patients?

Erik: Sure. So spending a lot of time doing work in both the pediatric and adult settings, I've probably done all four or five hundred broncs in adults and several thousand at this point in children. It's a really different procedure. The pediatric airway, so much smaller with most of our kids, were doing bronchoscopy for patients that are usually under one or two years of age. So your airway at most is going to be five, six, maybe seven millimeters versus an adult where you can get an airway that's going to be a centimeter or two. And it just requires a very different technique to be able to do the scope. There is a lot more limitation with what you can do in terms of working through the scope. And I think the bigger issue is our children are much more vulnerable when doing bronchoscopy. The very low FRC causes problems with really maintaining good oxygenation, that it just isn't seen commonly in adults. So you have to be extra careful with doing broncs in kids, trying to make sure that you keep their oxygen levels good, their heart rate's good, just requires a different skill set to be able to do broncs and kids and also a very different level of trust with our anesthesiology colleagues. We always teach our fellows that doing pediatric flexible bronchoscopy is probably the most difficult task that we can ask of a pediatric anesthesiologist.

Niklas: You have performed already some cases using cryo technology and we're going to talk about this a little more in detail in the next minutes, but maybe a question up front. What do you think would support the adoption, a more widespread adoption of cryo technology in pediatric bronchoscopy?

Erik: Well, I think with any tool that has been for interventional use in bronchoscopy and pediatrics, were always limited by size. That's typically our biggest problem is most tools are designed for adults and designed to go through adult scopes. So the size limitation creates a real difficulty, because I simply can't fit an adult therapeutic scope in most of the pediatric patients. So having smaller size tools to be able to apply would be very useful in terms of being able to apply interventional bronchoscopy, in particular cryo therapy in children. And the other big limitation right now is that the data in children is really extremely limited, mostly to case series and case reports about the use and potential uses in pediatrics. And we need to have a lot more knowledge about what can be done and what are going to be the indications in children, because they're going to be very different in adults. And so far, there's, I think, four centers in the United States that are currently doing cryo therapy in children, or at least have published to some extent in cryo therapy in children. But there may be more that are out there that just haven't written about it. But we're going to need to have people get together and discuss what can be done. What are the indications for doing it and how can we make sure that we're doing this safely in kids? Because children are not simply just little adults.

Niklas: That's something I used to hear in my med school time as well. They are not simply small adults. Mentioning data, I came across a publication of yours, which has been published in the American Journal of Respiratory and Critical Care Medicine, which is called flexible bronchoscopic thrombos cryoextraction in a neonatal on ECMO. So this was a real critically ill patient. First of all, maybe you can make our listeners a little bit better understand this. What patients are often in need of a bronchoscopy extraction of such a blood clot in your daily practice?

Erik: Sure. So ECMO patients are probably the most common situations where we have very large blood, blood clots that we need to extract. ECMO can be done for a variety of reasons. This particular child that you're mentioning was congenital diaphragmatic hernia and needed ECMO for chronic respiratory support will frequently see this for patients that are going to be in the ICU’s, whether for respiratory failure from illnesses or pneumonias or also very often in our cardiac ICU’s for patients that are undergoing congenital heart repair. Those are probably the three biggest areas where we're dealing with clot extraction. We will end up doing clot extraction in certain cases for spontaneous hemorrhage or also for tonsil bleeds, as are probably the most common other things outside of ECMO, where we've had to do clot extraction, although in those cases in particular, never mess with a clot unless you're prepared to deal with the consequences. Need to know why that clots there. So the ECMO patients are the ones we know why the clot is there in most cases, which is usually venous bleeding from being severely into coagulated, whereas other cases we may or may not know. So the ECMO ones or the patients that tend to be most interested in trying to extract clot when it's time to try to reinflate the lungs and come off that ECMO.

Niklas: Before you go to bronchoscopy, what would you do to avoid this formation of a blood clot in your patients?

Erik: Well, the blood clots are usually happening, and especially in the ECMO patients, and we're far away with that population. It's usually happening because of the anticoagulation. So if we can optimize the anticoagulation to keep the circuit flowing, but also to try to prevent spontaneous airway hemorrhage. That's, to me is the first place to start. And also making sure that platelet levels are going to be adequate, really just trying to prevent further bleeding into the airway if we can. If you can't change that, then using airway clearance is something that we can do, things like albuterol, hypertonic sailin plus or minus chest physiotherapy. Sometimes you want to be very careful about doing just peaty in patients that are on ECMO that we certainly don't want to dislodge the circuits. You can use mucolytics and thrombolytics to try to break up the clots, although especially in patients that are having spontaneous hemorrhage thrombolytics can make me a little bit uneasy. And also using ventilator strategies to try to help reinflate the lungs. Many of the patients are on lung rest because they're coming in being sick with some sort of viral illness or pneumonia or some other complication and trying to start actually inflating the lung, using a ventilator to recruit. It can be another nice step before moving towards bronchoscopy.

Niklas: Let's assume we have a patient where you decide to do bronchoscopy. Then what's exactly the right time to do it and in which environment would you then go for bronchoscopy?

Erik: Well, the timing, I think, depends on the disease process. Also, what we're trying to accomplish with the patient, if we're still working on lung rest, trying to get the lungs reinflate, it may or may not be necessary at that point. But it is time to start moving towards getting off ECMO. Recruiting the lung is going to be very important. Obviously, if the lung is not inflated, we're not going to be able to come off. And ideally, we can get this done before the clots become really solidified and inspected, because it's significantly easier to extract a clot that's not very hardened and fibrous. So doing it earlier is ideal if it can be done.

Niklas: Are there cases in the ICU, where you would do this bed side or do you do it in the bronchoscopy room with general anesthesia?

Erik: Sure. With the ECMO patients, one of the nice things with being able to bronchoscopy is we can do this straight at the bedside in the ICU. And whether it's in the neonatal ICU or the pediatric ICU or the cardiac ICU, we can do it at the bedside. And that's very helpful because we don't have to move the patient. When we're doing that, where our ICU colleagues are going to be doing sedation for us and monitoring the stability of the patient while we're doing procedural work. But trying to do it in the ICU for the ECMO patients is my preference. So we don't have to move the patient. Other patients that have had bleeding issues, we've certainly done in the operating room as well or in the cardiac cath lab is another place where we've been to have to try to do clot extraction. But the most common place is going to be in the ICU.

Niklas: Mentioning that you perform these extractions on the ICU bedside to me indicates that it's also important to have it done quickly and sufficient. So the recanalization, why is that so important in your set of patients? So children in that case?

Erik: For the kids, I think there's several things. One is going to be the sedation. So if you're doing a lot

Erik: of these procedures, the children will need to be sedated and trying to minimize the amount of sedation in the time that they need sedation can be useful. From a airway's standpoint we're usually doing clot extractions in patients that are having hemorrhage. And the more time we spend in the airway, the more chance there is to create airway trauma, whether from suction or the presence of the scope itself. To minimizing time in the airway can be very useful for protection of the bleeding that's already occurring.

Erik: And then from a practical standpoint, the longer you are spending doing bronchoscopy or any procedure,

Erik: the more people that you're pulling away from being able to take care of other patients are being able to do other work. So trying to do things as quickly and efficiently and safely as possible is certainly the ideal thing to do, whether in the ICU or anywhere else in the hospital.

Niklas: Actually, we're talking so much about the indication. So let's go into the procedure itself. Actually, how is it done? How do you do this procedure? How do you extract the clot using a cryo probe?

Erik: Well, first we would look at the chest X-ray and try to find the area that is going to likely be involved. The portion of the lung is atelectatic. Is it a low bar of involvement? Is it an entire lung or in many cases? Is it going to be entire wide out of the chest just to get an idea of where we're planning on going and trying to make sure that we're going to be efficient with where we're going to go, as many of our patients may or may not tolerate prolonged bronchoscopy as we were talking about a little bit earlier. Once we have an idea of where we're going to go, then we'll typically just start with a flexible bronchoscopy without cryo and visualize where the probe is going to be and what the extent of clot involvement or mucus plugging involvement may be there. Whether this is going to be something that is sitting all the way up to the endotracheal tube, or if it's down in the main bronchi or even more distal. At that point, usually we'll try to do some removal with suction and saline lavage and some of the more well-formed clots and mucus plugs that may or may not be adequate. And after we've given that several tries and we're not having good success, then typically would shift over to a cryo probe. So with the cryo probe, the most common one that we're using for clot extractions is either going to be the one point one millimeter or the one point seven millimeter probes in kids. And we simply pass that through the bronchoscope and try to insert that into the clot itself or the mucus plug itself. Usually it takes about a eight second free cycle or so get the clot really well stuck to the the end of the problem with being very careful to make sure that we're not getting stuck on airway mucosa and then try to pull out the whole thing in block. And usually within three, four tries, we're able to get the majority three, four tries, we're able to get the majority of the clot or the mucus plug removed.

Niklas: From the literature, we know some concerns that in patients this cryo extraction could rip open other vessels. What, from your experience, would be your common to that?

Erik: I haven't seen a lot of that. If we're doing things where we can visualize where the probe is going directly. So if we're doing into bronchial extraction as opposed to transbronchial biopsy as an example, I have not had problems with opening up new blood vessels because, again, you can see where the probe is going. I do think it's very important, though, especially in young kids with small airways, to make sure that you're not trying to adhere to the healthy airway mucosa. So being very careful to put the probes into a clot or into a plug or another object that may need to be coming out of the airway is critical to being able to do that. Where we have had a little bit of bleeding, not so much with clot extraction or with mucus plug extraction, but say other mass extractions, then we have been able to tamponade that bleeding either with some iced saline, topical afrin, topical epinephrine, other vasoconstrictors. But really, the bleeding has been quite minimal in the children that we've been doing into bronchial work with using cryotherapy.

Niklas: Speaking of things, other things in the airway than blood clots. You mentioned that I guess there's something more frequent in pediatric patients which can be stuck in the airway, which is foreign bodies. And I heard recently on a case where an infant aspirated a peanut, which was then removed with cryo extraction. How's your experience with cryo extraction of foreign objects?

Erik: Well, I never I'm thinking about foreign bodies in kids. My first go to is always going to be rigid bronchoscopy. Rigid has been used for years and years and it's very safe. It's very effective. We had tons of data on this. So it's always the first go to that, I would suggest, for trying to remove foreign bodies, whether it frankly in kids or in adults. But it certainly works very well. The area where cryo can shine is when you get foreign bodies that are in locations that a rigid bronch can't get to you. So as you start getting into lobar and segmental bronchi or say, for example, you have a patient that is not exposable with rigid instrumentation, which is a problem that we run into not infrequently. That is an opportunity where cryo can be quite useful. I will say I have not personally used a lot of cryo for removal of foreign bodies. There is some reports that have been out there where people have been able to do it successfully, but there is an opportunity to be able to do that for places where a rigid bronchoscopy cannot go.

Niklas: There are some reports from adults that became apparent with foreign bodies that were impacted and caused a post obstructive recurrent pneumonia. How time critical would you deem or consider the extraction of foreign bodies in the airway of children?

Erik: Yeah, I think foreign body is an emergency and that needs to be getting to the or as quickly as humanly possible to get them out. Leaving foreign bodies and children can pose a variety of problems in the acute setting, which just not being able to breathe. And having significant respiratory compromise is a major concern, especially in young children with small airways and then chronically, if a foreign body is left, say more distally where the child is not necessarily having significant respiratory compromise within weeks to months. You can certainly have problems with post obstructive infections. And I look after several children who had retained foreign bodies for a month or two that ended up developing pretty significant bronchiectasis and lung destruction in the segment where the foreign body remained. So I think you need to get foreign bodies out as quickly as is humanly possible.

Niklas: That's a very important information for our listeners I think. When you go for the extraction, what's the rationale for the choice of your tools or when do you go for the forceps and when would you rather opt for the cryo probe?

Erik: Most of the time, forceps, especially in the young kids through a flexible scope, they're really very difficult to be able to use. You don't have the grabbing power. They're a bit more difficult to manipulate, especially if you're using the 2.8 millimeter or 3.1 millimeter bronchoscope that had the 1.2 millimeter channels. You have a very difficult time getting forceps to be able to grab objects. We'll try it, but it has been a very difficult thing to do and something that I frankly try to avoid when I can, just because the limitations of the technology there. With that, the use of the cryo probe has actually been quite nice because I can get pretty good adherence to a foreign object or to objects in the airway. Even in the smallest patients. So I think giving forceps to try is a reasonable thing to do. But I have been historically very dissatisfied with forceps in general for foreign body extraction in children with at least through a flexible bronchoscope.

Niklas: When you freeze to a foreign object, when's the point you decide to start pulling it out? What's the sign you're waiting for to pull?

Erik: Well, I think first you need to be able to see the freezing zone on the object. So you can tell that your probe is actually on the object that you are trying to remove, that it's not hitting the airway. And once you've got pretty clear evidence to freeze, give the scope and the object that you're on, a little bit of a just a little bit of a jiggle, for lack of a better phrase, to make sure that you are where you want to be. And then once you have pretty well confirmed that you're attached to the object that you want and not something else, then you can start trying to pull it out.

Niklas: Maybe a comment also from my side, from the manufacturer's side is that you would only freeze two objects that contain water because the water is what freezes in the end and makes the cryo adherence to the probe. And there have been anecdotal reports also on metal objects that have been frozen. And these, of course, have been covered with fluid as well, to be frozen to. Nevertheless, we should keep in mind that although they are moist, surface allows them to have a cryo adherence. They are also very well conductors of thermal energy and may conduct the freezing to the bronchial wall. And we should be very careful once a child, for example, aspirated a penny or something to extract this with cryo. Erik, one more question on the cryo extraction for me would be, how's the safety in your experience compared to the other approaches used?

Erik: Well, so far we've used cryo with really not any significant complications in Cincinnati. It's worked quite well for the uses that we've been implementing. Haven't had any serious problems in frankly, in many situations. I think it's been superior to a lot of the other options that we've had for removal of tissue or removal of clot or plugs because of the reduction in time it takes to be able to do the procedure. The other thing that's been nice is being able to use cold temperature as opposed to using lasers for removal of tissue in particular has been nice because we haven't had any problems with airway fires. So from a safety standpoint, if I've been very happy with what we've been seeing with the cryo probes.

Erik: Children are not merely small adults. Performing bronchoscopies on children poses a special challenge for the bronchoscopist since their airways are a lot smaller than those of adults. Their tolerance to hypoxemia is much lower too. Therefore, under various circumstances immediate recanalization is required. Cryotherapy provides possibilities for swift recanalization of airways obstructed by blood clots, mucous plugs or foreign bodies while offering a more favorable safety profile than other modalities.Thank you, Dr. Hysinger, for sharing your experience, which will be beneficial for other bronchoscopists as well and Niklas for being here today. Stay tuned for our upcoming episode about debulking granulation tissue using cryotechnology as opposed to other modalities and the role this technology plays for palliation of central airway tumors.Thank you for listening to our medical insights podcast, a podcast by the Erbe group. To get further information and view our terms and conditions, please visit our website at www.erbe-med.com.