Hello, everybody. This is Frank Ng here. First, let me thank the organizers for inviting me to give this lecture. My lecture is entitled homeostasis for the very low birth weight infant during transportation and in the cath lab. Before I start, let me just say that PDA occlusion has been around since the late 1980s to early 1990s when I was a fellow in junior faculty. Ever since then, several devices have been developed to occlude the PDA. However, it was only in the last few years where devices have been developed and designed to go through small delivery systems such that it can be done in the very low birth weight infant. What I mean by that is those premature infants weighing 1,500 grams or less. Here are my disclosures. For this discussion where we'll talk about comorbidities of the neonate and premature infant, homeostasis issues for the neonate and the premature infant, transportation and preparation in the cath lab, pre-procedural huddle and post-procedural debriefing, the development of a checklist, and ongoing QI project. Here's an example of a 1,000 gram premature infant in the cath lab. You can see how small they are compared to the human hand. Here are a pair of twins who weigh about 800 grams each having had their PDA occluded. Here's a 625 gram premature infant. You can see how small he is in comparison to the standard cath lab table. A closer picture of the infant seeing how the skin is so thin that you can still see the blood vessels underneath the skin. Here's a 570 gram premature infant with such a sick lung that it required to be an oscillator before we brought him down to the cath lab. You can see again the transparency of the belly, skin, and the vessels underneath it. Here are two of the devices that have been developed in the last few years that have enabled us to occlude the PDA using these two devices. One is called the MVP, the microvascular plug, and the other one is the piccolo ductal occluder, which got FDA approval recently. Just shown by comparison, there are two three millimeter diameter devices just compared to the size of a dime. You can see how small they are. For those of you who are not familiar with this procedure, let me just do this and introduce you to how this works. We'll put a catheter from the femoral vein and go up the right heart to the PDA, cross the PDA into the descending aorta, and we take this picture. You can see from the red arrow the size of the ductus. This ductus is almost as big as the pulmonary artery. It's a huge PDA. Again, this is after closing the ductus with the MVP device. You can see this very easily, the two black dots that represent both the distal and the proximal edge of the device within the ductus. After the device is placed, we can use echo to look at the flow of the adjacent anatomy. Most importantly is after the device is put in, we want to make sure that the pulmonary artery flow is normal. Here you can see that the blue flow represents non-turbulent flow and the red arrows define the right pulmonary artery and then the left pulmonary artery. It looks like there's pretty good flow. Then we go on to look at the aorta. You can see again this blue flow of down the descending aorta where the red arrow points to the area where the PDA might have protruded into the aorta. Here you see the flow is very good. This is what the x-ray looks like on this patient before occlusion. This is what it looks like after. You can clearly see the lung is much darker. There's more air in there instead of fluid. The heart size has shrunk and the edges are more clean. You can also see the little white dot where the device is located. It's not uncommon to see the x-ray that was taken that morning before the procedure and the x-ray a few hours after the procedure. You see this very significant chest x-ray changes right away. Now here's another one with a very large ductus measuring about 2.7 millimeter in diameter. Now again in a small baby this is actually quite large. Again the best way to think through this is just look at the size of the ductus compared to the pulmonary arteries and it's almost the same size so it's huge. We take a still picture. We measure it. In this case it measured 2.7 millimeters in diameter with a length of about 10.3 millimeters. There's a temp probe there as a reference knowing that by using this reference we can land the device inside the ductus quite easily. It's almost always that the PDA sits in front of the temperature probe or the NG tube. So here's the picture on the left giving you the still frame and seeing where the temperature probe is and you see the device is now delivered just in front of that temperature probe defined by the red arrows I showed here and the yellow arrows is the position of the temperature probe. So we know that this device is in good position if you use the reference angiogram and this is what it looks like after delivery. The device is still sitting in the ductus and we took a picture of the pulmonary arteries showing that there's good flow to both the right and left pulmonary arteries and then we release it and you see the device is quite stable. It's sitting in the position of where the ductus ought to be and we're happy with this picture. So again on the angiogram on the echocardiogram you see that the device is in the ductus. The blue flow represents the aorta which shows good flow there. There's no obstruction and then if you look at the pulmonary arteries also shows there's pretty good flow to the pulmonary arteries there as well. Again this is the device before release. It's sitting quite stable within the ductus and we're very happy with this result. Again here's the x-ray showing the edema in the lungs, the large heart and you see that a few hours later you can see that the lung markings have cleared up, the heart has shrunk and the edges are much more crisp which tells me that the lungs are clearing. Now this is not a rare thing. We see this all the time. The picture that I show you with a 570 gram patient on an oscillator you can see the initial x-ray on the left side. You can't even see the heart because the fluid in the lung is thick enough to obscure the edges of the heart. The next day you begin to see the lungs more clear and then by sorry the day after the procedure you can see the device sitting right over the upper part of the left heart and the lungs have cleared up somewhat and the heart has shrunk in size. So again we know that the lungs can improve significantly once you close the PDA and this is not a rare finding. We see this all the time. Again another one with x-ray before and after you can clearly see the heart getting smaller. Here's another one. Here's another one. The lungs feels are very congested before and after the procedure it's cleared up. Again just more of the same improvements that you can see when we do this procedure. Okay so we actually presented this data back in 2020 at the Society of Cardiangiography and Interventions and it was a QI project that we had done because we wanted to make sure that we were able to provide transportation and as well as working in the cath lab in such a way that these small babies do not lose their core temperature. So it's maintaining homeostasis, thermal homeostasis, as well as to make sure the fluid is adequate, not too much, not too low, checking glucose, checking many different things that might be particularly important to the premature infant just because of their size. So basically early in our experience we took the data from May 2019 to February 2019 and basically we formed a multi-disciplinary team including the interventionists, which is myself, the neonatology team, anesthesiology members of the cath lab team, and bedside nurse and we got together and before each procedure we had a huddle that talked about the specific needs, peculiarities, comorbidities of the premature infant. After we do the procedure we got back and debriefed each other to see could we do things better. Out of that we developed a protocol and a checklist was developed for the transportation to optimize temperature, glucose, and ventilation homeostasis. We refined the protocol and what we did in the lab after each case and so therefore over time we just got better and better and was able to avoid a lot of the potential side effects, adverse events that might be related to maintaining homeostasis in this group of patients. We looked at the patient profile, the cath lab data, and analyzed their early outcomes and here's just a brief summary of this. Again, this was early in the experience. We had 19 patients. You see the median birth weight of 735 grams and that's the birth weight, but the weight at that time of cath was about a thousand grams, 1060 to be exact. The minimum diameter range was 257, 2.57 millimeters, and the length was about 12 millimeters. The kid I showed you earlier, that 570 gram patient, came after this study and we had successful closure. At that time we only had the microvascular plug and subsequent to this after the FDA approved the piccolo device we started using that device as well and we found that we had six preventable adverse events and that included mild transient hypothermia. There were two cases, hyperglycemia in one case, hypoglycemia in one case, atelectasis in one, and wire perforation during the procedure in one. We found that we can improve homeostasis, thermal homeostasis, by improving how we drape, how we warm the baby. We were much more careful in the use of glucose and checking glucose levels, the ventilatory management with each subsequent procedure we had improvements. So out of that we developed a checklist and we use that checklist with the goal of minimizing the transportation time depending on the different hospital settings. These can be altered to meet the needs of a specific hospital. Some of the simple things included maintaining sufficient battery backup power for the isolate. This sounds like it's intuitive but if the staff does not plug the isolate into the wall during the procedure the battery might have run out by the time we brought the isolate back into the cath lab for transportation and that happened to us once at which time we realized that even for the simple short transportation from the cath lab to the neonatal ICU the patient lost some core temperature just because of the loss of power so that we could not keep the baby warm. Again these are the kinds of things that we learned and improved upon over time. We learned how to use force air warmers, chemical warmers, IV fluid warmers, and I'll show you some examples of this. A heat lamp, we learned to increase the ambient temperature in the lab itself using plastic wraps to minimize insensible losses and retain body heat. We learned to remove the gel from the transthoracic echo after each interrogation just so that the liquid does not evaporate and make the baby colder. We had proper sizing of temperature probes. We had judicious use of IV glucose adjusting the ventral management based on the bedside nursing experience with the infant. That we learned to be very important. If the nurse tells us that that baby requires frequent suctioning then we will do that in the cath lab and avoid any potential risk for atelectasis or other pulmonary adverse events. We learned from the nurse what is the most optimal position for the infant and use that in the cath lab. We use cerebral and renal nears to monitor the flow and the perfusion into these organs and so the conclusion of the abstract was that the transcatheter occlusion in very low birth weight infants can be performed successfully while maintenance of homeostasis in this high risk group is challenging. A vigilant multidisciplinary approach utilizing a standard protocol and checklist might mitigate adverse events. Further studies to confirm efficacy and safety are warranted. So following this study we continue to have these pre-cath huddles and post-cath debriefing and we have not had any additional adverse events again just because we were very vigilant about making sure with this checklist get all checked off and dot all the t dies and cross the t's and we've done so far 57 cases as of this month. So let's go through the list itself and see if some of the items that were useful for us. So the isolate for transportation we had to make sure that the transporter system had a backup battery. We made sure they plugged into the power while the patient is in the lab to keep the battery power full. We made sure the isolate had a warming feature. We've learned that some isolates do not have warming features and we just have to make sure these are the checklists that say check off does this particular isolate that's going to go down to the cap have a warming feature. We also have backup chemical warmers. These are basically little chemical warmers that are used to warm up the heel for heel sticks just so that in case something goes awry we have something we can use to rapidly keep the baby warm. We made sure that the isolate temperature mode is set to air temp and not skin temp and what that means is that the air temp is what you really want to set up the the temperature in the baby not necessarily on the skin which is will make the the numbers go off. We learned that very early on that the mode has to be checked to make sure that it's set properly. Chemical warmers these are similar to the air foot warmers that I mentioned that are used for heel sticks. Heat lamps are very important making sure we have the heat lamps in the cath lab to maintain a little bit of heat for the body especially when it's exposed for sterilizing cleaning before the cath. We have forced air warmers. Some of these are called the infant bear huggers. Make sure we don't use the adult size but the baby size so that it can be used turn it on have it ready before we even transport the patient on move the baby from the incubator. We increase the cath lab in temperature up to 75 76, it's not very comfortable for the operators, but by the time we're done with the procedure, we may be full of sweat, but it's better for the infant. We actually learned this from the anesthesiologist using plastic wraps. I think of them like saran wraps, where they would actually use that to cover the head, cover the chest, and not only does it improve core temperature, maintain core temp, it also minimizes insensible fluid losses. After each trans-thoracic echo interrogation, we used gel to look at, to get better images, and we learned to wipe them off in between just so that the baby's skin is dry and not moist from the gel. The temperature probes, we spent a long time deciding should we use rectal temperature probes or axillary, or what might be better. Now, initially we thought the rectal probe was good, but it turns out that the esophageal temp probe worked the best because it also offered as a reference to where we could put the device when we look under fluoroscopy. Homeostasis for glucose, we tend to use D10 half or normal saline, or if the patient comes down in TPN, we'll use that. We have peripheral IV access for giving glucose if we need. We monitor that. We know that stress can cause hyperglycemia, so we pay attention to those levels and adjust the glucose as needed. As far as the airway is concerned, the ventilator, we minimize the changes prior to the cath lab. In other words, the baby usually gets intubated in the NICU. All the settings are set up so that by the time the patient comes to the cath lab, we don't have to spend extra time intubating or making adjustments. Oftentimes, we have a neonatologist or a fellow come down just to help out with the ventilator at the beginning of the case. As I said, the babies are intubated in the cath lab. Again, we know that infant ventilators are very unique for this size patient and we don't use the ventilators that are typical for older patients that are in the cath lab. We'll bring with us a portable end tidal CO2 to monitor the respiratory system. We learn to bring long tubing. The reason that's the case is because the babies are small and as we move the table, sometimes the shorter tubing is just too short for the amount of movement on the table. So having these long tubing, we call them MRI tubings. That's what's used when you roll the patient into the MRI machine to give a little more length so that the table can be shifted around without pulling on the tubing itself. These are simple things, but we have to think about them for the size of this baby. If you have a checklist, you just don't forget. We bring the O2 blenders and our respiratory therapists are involved with that during the transportation. We'll bring our transcutaneous CO2 monitoring, the TCOMs, the oscillator. If the baby is on an oscillator because the lungs are so bad, we have specific transportation systems for that and I'll show you an example of that later. Appropriate food for the premature infant. We use D10. Again, we just have to be aware of glucose levels. The cath lab fluids, we tend to use heparinized saline. We do not give a bolus of heparin because of the premature state. We worry about the intravacrinal hemorrhages. We ask about any history of hyper and hypoglycemia with the bedside nurse and again, we're just alerted to some of the potential issues and pay attention to that. We have IV fluid warmers. An example is something called Hotline. There are other ones where the fluid is run through the machine and warmed up by the time we get it out of the IV tubing. Again, paying attention to type of saline and glucose for the specific premature infant. So, we learned the history of airway management from the bedside nurse and we found that the bedside nurse is crucial. They know that baby better than anybody else. How often does the baby need suctioning? What is the baby's favorite position? And we try to use those positions in the cath lab. Careful monitoring with NIRS. Here's an example of the fluid warmers that we use. The tubing goes through that machine and warms up the fluid as it passes through another type of air fluid warmer. This is a chemical warmer. The neonatal ICU, we use this for the heel sticks and we use that for the babies if we run into trouble with the baby being too cold. So, here's an example of the plastic wrap that was put around the head just to keep the baby warm and prevent insensible losses. You see this with the plastic wrap over the head. You see how small the babies are. They're tiny when it comes to the draping. And then you see how the anesthesia is involved. Again, plastic wraps, the heating lamps. We use ultrasound to guide our vascular access because these vessels are quite small. You can see how when the oscillator comes in, it's a very tight cath lab space and we have to pay special attention to the oscillator because it has very stiff tubing and that can easily separate and change the position of the ET tube. You see the oscillator working there. This is a baby who had such bad lungs it needed to be an oscillator. The intervention sits on the right side of the cath lab. The echocardiographer is on the left side providing echo images and you can see that they stay underneath the drapes to help us interrogate the vessels, the flows, and then after we deliver to make sure all the flows are good before we release the device. So, here you see one of our echocardiographer's hands underneath the sterile drapes giving us the echo images. You see in this particular baby we had the chemical warmers over the head just to keep him a little more warm. So, you go there and again just a close-up of how the position of the hands are underneath the sterile drapes over the baby's chest. We have the cerebral nears on the forehead. See that on the yellow arrow there and then also in the back with these are renal nears. We also, each cath lab is going to be a little different in terms of how they design the space. In our lab, we've learned that we have to take our lateral system and move it away to the bed of the foot of the table before we bring the baby onto the table and then move it back. So, these are things that should be discussed ahead of time so that we have all this planned out before the baby gets transferred. We get an idea of where each of the pieces of equipment should sit. Sometimes there's just so little space that things don't always fit, right? So, you have a plan to look at your cath lab space. Where's your biplane system monitors? Where is the ventilator that's going to be sitting? Where's your contrast injector? Now, in this case, we really don't use an injector. We use hand injection, but where's the baby's ventilator? Where is the TECOM machine going to be? Where's the echo machine going to be sitting? Just so that you have that in advance before you bring the baby in. So, where the equipment is placed is going to be key for smooth transportation and transfer to the cath lab table as well as back into the isolette. As I said, we take our lateral flat panel down to the foot of the table, settle the baby, and then move it back. We found that to be the most efficient way of avoiding machines that will fit properly. The echo machine, the echo monitor, the NICU ventilator, the fluid warmers, all this takes space and we have to think about this in advance where we'll place them when the baby gets there. We minimize simulation of the baby. We minimize our transportation time and time in the cath lab. We consider early sedation prior to transportation. We prepare in advance your blood products. Some babies may need INO and all the different supplies should be ready and easily retrieved when we need them. As I said, we have the long tubing, the extended tubing. We have our sinus type for IV access. Sometimes we actually have learned that we have these special clear drapes for the premature infant. I'll show you an example of that. We minimize the time in the cath lab. The peripheral IVs are placed in the NICU before they come here so the anesthesiologist does not have to waste time putting IVs in or they will have PICC lines. We learn about where they are. You don't want to access a femoral vein that has a PICC line in it already so you know that up in advance. Some of the anesthesia and different anesthesia services may have different protocols. This is what we use. We communicate with all the parties and we huddle the day before the cath. Again, as I said, includes the neonatologist, cardiologist, the respiratory therapist, the bedside nurse, a pharmacist sometimes, parents, and then the cath lab tech. The neonatology staff or the fellow may come down and join us to help us set up, especially take care of the ventilator early on. We discuss the particular needs of the patient. Is this an IDM baby? Does the baby have any history of brain hemorrhage, vascular access issues, anemia, and these are things we learn in advance so that we can prepare. We ask about the hemoglobin and we'll transfuse if the patient is anemic before we do our procedure. We ask about the renal function. How's the creatinine? If the creatinine is hand, we can dilute the contrast to minimize insult to the kidneys. We've learned that if you dilute it to two-thirds contrast, one-third saline, you can still get an adequate image to make the measurements, but that's less contrast for the kidney to remove, especially if there's renal dysfunction. We ask about the PICC lines. As I said, you don't want to have a PICC line in the right leg and then you access the right leg and find that there's a PICC line there. So you learn that in advance and you plan out which side you're going to go based on the PICC line positions, for example. We place the blood pressure cuff in the SAT machine on the opposite leg for the access so that you don't have disruption when you have a sheath on that side of the leg for access. As I said, there's a pre-cathedral, post-catheter breathing, and all the needs of the baby are specifically discussed. And we debrief afterwards to ask, were there any adverse events? Could we have done things with improvement for the next case? And we did this early on until we found out everything was done properly. But we still do it because every once in a while, you might find something that may be needed and we'll add that to the checklist. So here's an example of a transportation team that takes six people to bring these babies down. Again, it's a huge fanfare, at least where we are, because the NICU is quite far from the cath lab. You see that we have our neonatologist with us at the beginning to settle the baby, make sure the ventilator is working fine, and all the things that he's concerned about is in order. For the oscillator, which is a much more specialized machine, it's even a bigger team, eight-man team transporting a 800-gram baby with the oscillator. So you see how there's careful transportation from the isolette to the cath lab table. This is actually a special machine called the TXP system. And this actually has a portable high-frequency ventilator that we use for babies who are on the oscillator now. So it makes the transportation and the transfer to that much more easily. And there's not a loss of ventilator changes during the transportation using this system. Here, we're just prepping the groin. You see how the baby can get quite cold, and we keep the body draped, but sometimes we open up everything and we'll have a heat lamp there to maintain core temperature. This is the anesthesia monitoring machine. The TCOM is there to show your transcutaneous CO2 monitoring system. We found out this particular sheath has the lowest outer diameter, so therefore it allows a minimal size of the delivery system into the leg of the baby. Other issues include fragile skin. We learned to use certain blue tape that's not too sticky, so you don't rip the fine, tender skin as you remove tape. Neuro-patches is one of the things that we found actually create irritation on the forehead, and I'll show you that example, and we learned from that as well. We look at the kidney levels, creatinine levels, and again, we have learned to dilute contrast to one-third contrast, one-two-thirds contrast, one-third saline, just to minimize the contrast. We found that this combination is still good enough to see the images that we can make our measurements. We use one CC syringe for flush only, so therefore not a whole lot of fluid. So it's just that we minimize all the extra fluid that we give as part of the procedure. Hemoglobin, we transfuse ahead of time, as I stated. Infection risk, we pay attention to venous stasis and thrombosis. I'll show you some techniques of how to minimize and mitigate that. Again, we have to be aware of any lower extremity PICC lines, and we use a contralateral vein. Blood pressure cuff sits on the opposite side, as I mentioned. Here's an example of a baby that had upload atelectasis, and after we went and debriefed, the bedside nurse said, you know, we had to suction this baby every 30 minutes. Well, had we known that in advance, we would have done an NCATHAB, so that gave us the idea that we really have to include the bedside nurse to ask about the specifics of the infant before we start. So here's an example of a cerebral nearness creating a little irritation on the skin. Luckily, it got better a few days later, but again, after that, we've learned to use these very lightly sticky blue tape that comes off easily, and we've learned that this Kavalon material, if you wipe it on the skin, can also allow the tape to be removed more gently, and that's been very helpful. Again, all this is a result of our huddle and our debriefing. After we finish, we pull the sheath, and I actually do some local massages in the foot, the calves, and the thighs, just to improve some microcirculation as we host the groin site for hemostasis, and just how we do that, and I'm sure the babies like that afterwards. You can see how blue and venous stasis that leg looks, and after we massage it, it actually looks a lot better. Again, this is not photoshopped. This is as a result of using just some local hand massaging of the legs. Just this use of radiation. Now, we use echo to help us to minimize the use of radiation, so we've learned that we can decrease the need and dependence of fluoroscopy, minimize the use of contrast. We avoid arterial access, so we don't injure the vessel, the arteries, because echo can help us in some of the imaging. We know that there's published data that shows that 10% of neonates can have an injured femoral artery if we use it, so we avoid that totally. Summarizing this, neonates and premature infants have fragile hemodynamic status and immature homeostatic mechanisms. Transportation and procedures performed outside of the NICU can be problematic and render instability of hemodynamics and homeostasis. Homeostasis during transportation and in the catheter is essential, requiring a multidisciplinary approach, routine pre-catheter post-cath debriefing, development of a checklist and standardized process. Echo guidance eliminated the need for femoral artery access, decreased radiation exposure and contrast load. And with that, I thank you for your attention.

homeostasis

low birth weight infants

PDA occlusion

premature infants

transcatheter occlusion

thermal homeostasis

multidisciplinary approach