Doctor reviews: 14 Questions and Answers on Neonatal Ventilation!!

Hello, I'm Dr. Tala, a board certified neonatologist. Our members asked that we have more multiple choice question type videos, so if you want that sort of power, then think about joining our membership. Right, let's get started. Question number one. Which of the following scenarios would make you think the lung pathology is more likely to be TTN, transit tachypnea of the newborn, and not RDS, respiratory distress syndrome? A, needing 21% FiO2 on CPAP in a term baby. B, ground glass appearance on the x-ray. C, a 28-week infant with severe retractions in the delivery room. Or D, infant needing oxygen at seven days of life. And the answer is A, needing 21% FiO2 on CPAP, or basically room air CPAP. As I'm sure you've all realized, TTN and RDS can sometimes be really difficult to differentiate, even on an initial x-ray. And they're definitely difficult to differentiate on exam. They're going to present with grunting, retractions, cyanosis, maybe nasal flaring. So a lot of what we go on is really based on the course, obviously, as well as the x-ray. So the x-ray in TTN is more likely to be slightly hyperexpanded. You are more likely to see kind of like wetter lungs. So interstitial fluid or that starburst appearance, as well as maybe fluid in the fissure. With RDS, you're more likely to see hyperexpanded lungs. So maybe kind of like six, seven ribs expanded. You're more likely to see air bronchograms. So you can kind of follow like the bronchi as if they're like a tree down between the lungs. And you're also more likely to see just overall haziness in the lungs. With TTN, you're also less likely to need as high oxygen. So if a term baby is grunting away and you put the baby on CPAP, they're more likely to just need 21%. Whereas if it's like a 37-weeker needing like 35%, then it's more concerning that this really is RDS. Immature lungs plus the fact and deficiency. The other big difference between them is TTN, as it says in its acronym, is transient. Normally it lasts up to about three days. If you still have a baby on oxygen at seven days, you can't really blame it on the TTN. RDS can linger for some time and then develop into other lung diseases like chronic lung disease or bronchopulmonary dysplasia. So often it is difficult to differentiate between the two. We're kind of going on the course a lot. Question number two, why are conventional side breaths ever used with a high-frequency jet ventilator in neonatal practice? A, for improved patient comfort. B, to decrease volume trauma. C, to aid in alveolar recruitment. Or D, to reduce mean airway pressure. And the answer is C, to aid in alveolar recruitment. So we try to avoid side breaths or these like intermittent breaths given by the conventional ventilator when a baby is on the jet. By definition, or a lot of the times we're putting the baby on the jet to hopefully give a very gentle way of ventilating and oxygenating for the baby. Normally the jet pip or the peak inspiratory pressure that we're typing in or that we're putting into the machine is kind of dampened down. So the alveoli are not seeing this really high pip that we're giving. Whereas when we're doing side breaths or the intermittent breaths, those are driven by the regular conventional ventilator that we also use in conjunction with the jet. Go watch the jet video. But those are delivering the full pip and the alveoli is seeing the full pip that we are typing in with those side breaths. So if we are going to use them, they're really to just try to kind of open up the lungs a bit. And you want to use as low a rate as possible with as low a pip as well as possible. So really we use kind of two to four side breaths in a minute. And generally, if a baby is on the backup rate or the side breaths or the intermittent ventilation on top of the jet rate, then you only want to do it for 12 to 24 hours. Like really as little as possible so that you can open up the lungs again and then go back to the like gentle way of ventilating the baby. So side breaths do definitely not help the overall volume trauma because if anything, the alveoli are seeing higher pressure. Question number three, let's keep talking about jet. If a neonate is on the jet and you diagnose PIE or pulmonary interstitial emphysema on an x-ray, you would want to do all of the following except A. Increase the eye time. B. Decrease the rate. C. Decrease the P, which is the positive end expiratory pressure. Or D. Accept a higher FiO2. And the answer is A. Increase the eye time. So basically, we do not want to increase the eye time. We want to do all the other things. When you have PIE or pulmonary interstitial emphysema, which is a type of air leak, basically, air is escaping through the walls of the alveoli. So there is damage to the walls of the alveoli. So what we really want to happen is the alveoli to collapse just a little bit, not completely. We still have to oxygenate babies, but just collapse a little bit so that the walls can approximate each other and they can heal. So what we can do for that is we can decrease the P, the positive end expiratory pressure. So you're not pushing as much pressure to try to keep those alveoli open. You can also increase the expiratory time. If you increase the expiratory time, then more of that gas will be able to leave the alveoli. And so the alveoli can approximate each other. So one way of doing that is to decrease the rate, because as the rate goes down, each breath lasts a longer period of time. So you have a longer period of expiration. Like we already said, we don't want to increase the I time, because if you go up on the I time, you'll go down on the E time and you'll have less time for that air to kind of leave. Generally, you want to ventilate and oxygenate babies with any air leak syndrome as gently as possible. So often, anytime a baby has an air leak syndrome, we'll allow a slightly higher FiO2 and sometimes even a PaCO2 just to kind of like get the baby through it until the air leak heals. Question number four, while we're talking about air leaks, which of the following is not considered an air leak syndrome? A, pulmonary interstitial emphysema. B, pneumothorax. C, subcutaneous emphysema. Or D, pneumatosis intestinalis. And I know you all know this. The answer is D, pneumatosis intestinalis. An air leak syndrome is, by definition, when air leaks out of the tracheobronchial alveolar tree and leaks into areas where it shouldn't be going. So that could be through the walls of the alveoli, like we see in pulmonary interstitial emphysema. It could be into the pleural cavities, like we see in a pneumothorax. It could be into the skin, like we see in a subcutaneous emphysema. It could be into the pericardial space, like we see with a pneumopericardium, or into the mediastinum space, like in a pneumomediastinum. Lots of words there. So this is all air originating from the tracheobronchial tree. Pneumatosis intestinalis, as you all know, is the hallmark of necrotizing enterocolitis. And that is when air gathers in the intestinal wall. That air is thought to be produced by the bad bacteria. And so that air is not originating from the tracheobronchial tree. Which of the following is the most appropriate initial management step for a neonate on conventional ventilator who develops a pulmonary hemorrhage? A. High dose intravenous corticosteroids. B. Increasing the peak on the ventilator, the positive end-expiratory pressure. C. Starting inhaled nitric oxide. Or D. Starting broad-spectrum antibiotics. And the answer is B. Increasing the peak, or the positive end-expiratory pressure. What you're hoping to do is by increasing the pressure that the alveoli are under, you're hoping to tamponade, or like stop more of that blood coming out from the alveoli and up the tracheobronchial tree. So going up on the peak is probably one of the first things that you want to do if a baby has a pulmonary hemorrhage. You could also go up on the pip and the eye time as well. That will also increase the general mean airway pressure that the baby is seeing. Maybe eventually you want to put the baby on another breathing support, whether it's the oscillator, or specifically the oscillator is probably more helpful here because you can go up on the mean easier. Other things that you want to do when a baby has a pulmonary hemorrhage is suction out the blood from the ET tube if you literally cannot get gas exchange. You need to replace the blood products. You can try ice water down the endotracheal tube as well as intratracheal epinephrine, and just overall changing the vent settings so that you can support the baby as much as possible. Eventually, you might consider steroids or INO if there's enough damage to the lungs or something else is going on, but it's not the first thing that you would do. If you think that sepsis is the cause for the pulmonary hemorrhage, then obviously you have to start antibiotics. Even if you order antibiotics, it's still much quicker to go up on the pip than to actually give the antibiotics. So really the first thing that you would do is go up on the pip. Question number six. A 30-week gestational age neonate is admitted to the NICU with respiratory distress shortly after birth. The neonate has tachypnea, nasal flaring, grunting, and has an oxygen need. You decide to start CPAP therapy. Which of the following is the primary mechanism by which CPAP helps improve oxygenation and neonate with respiratory distress? A. Increasing the functional residual capacity or the FRC by preventing alveolar collapse. B. Providing positive pressure to the upper airways to reduce the risk of apnea. C. Increases surfactant production in the lungs. Or D. Promotes bronchodilation to reduce the airway resistance. And the answer is A. CPAP helps by maintaining a constant positive airway pressure, which basically prevents alveolar collapse and also improves lung compliance and maintains that functional residual capacity. So that not every single time that the baby takes a breath, they have to pop open all the alveolar again. So the alveoli are just kind of staying open a little bit. That's what the functional residual capacity is. CPAP can decrease apnea prematurity by giving babies the support that they need. CPAP in itself does not increase surfactant production and there's no direct medical reason for causing bronchodilation. But CPAP, especially in the upper airways, can kind of stent the airways open a little bit. Remember, CPAP is the same as the PEEP that we're giving the positive end-expiratory pressure that we're giving when babies are on the ventilator. So that constant amount of pressure maintaining the functional residual capacity. Question number seven. Which is true of high flow nasal cannulas? A. It's an invasive form of ventilation. B. The amount of support is measured in centimeters of water pressure. C. It can provide blended oxygen. So anywhere between 21 and 100%. Or D. Prongs should be completely occlusive in the NAERS. And the answer is C. High flow nasal cannula can provide blended oxygen. So it can give oxygen anywhere from 21% or room air all the way up to 100%. Although, as you all know, because it is an open system, even if you're dialing in 100%, the baby really isn't receiving 100% FiO2. And as we've talked about already, there are different graphs that you can look at which will actually calculate how much the actual FiO2 a baby is receiving dependent on the FiO2 the baby's on, the flow, the weight of the baby. So the high flow nasal cannula is a heated, humidified way of delivering oxygen non-invasively. The baby is not intubated. So it's a non-invasive form of respiratory support. The baby has prongs in and the prongs are relatively loose. So there's a leakage around the prongs, unlike with CPAP. In high flow nasal cannula, there's a leakage around the prongs so that it's more comfortable for the baby. And also so the carbon dioxide has a way to get out as well. The way that we deliver the flow in babies is with the unit of flow. So we give it in liters per minute. It's not like a pressure that we're setting like in CPAP because we don't really know what the pressures are going to be given. High flow nasal cannula definitely does give some amount of pressure, but it's less than CPAP. And that isn't really the goal of the high flow nasal cannula. Generally though, the higher the flow, the tighter the prongs, the smaller the baby, then the higher the amount of pressures that the high flow nasal cannula is going to deliver. Logically, it's still going to be less than CPAP. So if you're on five liters of high flow nasal cannula and you put the baby on CPAPR5, CPAPR5 is going to be giving more pressure or a better FRC to the baby than the five liters per minute of high flow nasal cannula. Question number eight. Which of the following can be used to diagnose a pneumothorax? A, transillumination of the chest. B, a chest x-ray. C, an ultrasound. Or D, all of the above. And the answer is D. Like I keep saying, if you see all of the above, most likely the answer is going to be all of the above or none of the above in medicine. So always lean towards that one if you ever see those as options. So a pneumothorax can be diagnosed in different ways. The classical way that we always think about diagnosing it immediately at bedside is transillumination. So you can get a light, whether it's a flashlight in a tiny little baby or the light that you use to kind of help you get the IVs or art lines or whatever in. If you put that off at the chest, then the side with the pneumothorax will like glow a lot more brightly than the other side. If the baby is crashing, then that is enough of a diagnosis for you to just go and needle that side of the chest. The classical way that we diagnose pneumothoraces is with a chest x-ray. And when you get a chest x-ray, it's going to appear, you know, the lung is going to be kind of collapsed, moved into one side, and you'll see an area of blackness with no lung markings where the air is on the side of the pneumothorax. Now, increasingly, ultrasounds are being used more at bedside to diagnose pneumothoraces. Obviously, this is quick. It doesn't involve radiation, but it's also very user dependent. Question number nine. A full-time neonate was just admitted to the NICU from couplet care because he keeps having severe cyanotic spells. In the unit, you notice that he turns pink when he was crying, but becomes cyanotic when feeding or when he's asleep. What is a likely diagnosis? A, TTN or transient tachypnea of the newborn. B, choanal atresia. C, tracheoesophageal fistula. Or D, laryngomalacia. And the answer is B, choanal atresia. And that basically is a bony blockage at the back of the nasal passages. Babies are obligate nasal breathers. So unless they're actually crying when their mouths are forced to be open, the rest of the time, they should be breathing through their noses. So if their noses are blocked entirely, the nasal passages are blocked, then babies are unable to breathe. If it's unilateral, it may take a really long time to actually be able to diagnose it. But if it's bilateral, then these babies may have to be intubated just to maintain their airway. And this really is the classic picture. When the baby is crying, the baby is pink. And the rest of the time, the baby is pretty much cyanotic. The way that we can diagnose this in the NICU is by threading a gavage tube down the nares and hopefully down into the back of the throat and down the esophagus. If you can't pass it through, then that's what we're really worried about. So choanal atresia. The diagnosis can be confirmed with endoscopy. So ENT can kind of go back and directly look through the nasal passages. Or often we'll use a CT scan as well. And this will need surgical correction to actually recreate those nasal passages so babies can breathe. Question number 10. Which of the following is not a potential sign of respiratory distress? A, grunting. B, subcostal retractions. C, cyanosis. Or D, acrosinosis. And the answer, I'm sure as you all know, is D, acrosinosis. Acrosinosis is when the peripheries or the hands and the feet appear slightly blue or purplish but the baby is centrally pink. So the lips will look nice and pink. The baby's face, the rest of the body will look pink but the extremities are kind of a bluish color. This is very normal in newborn babies. It's to do with the immature vascular tone and that can continue for several weeks. Infants can have many different signs of respiratory distress. Whether it's tachypnea, breathing more than 60 times a minute, grunting where they go, uh, uh, uh, which is when they're trying to kind of create their own peak or their own functional residual capacity. They can have flaring where their nostrils are kind of going in and out. They can have subcostal retractions where the skin gets sucked in under the ribs or above the sternum or whatever and you're actually seeing the baby working hard to breathe. These are all kind of more classical signs of respiratory distress. You can also have cyanosis if the baby really isn't getting enough oxygen in and that's when the baby starts to look blue because they have a low oxygen saturation level. Obviously, lots of things can cause cyanosis but so can respiratory, bad respiratory distress. A, it is a high frequency ventilator. B, it always runs in tandem with a conventional ventilator. C, the jet pip, the peak inspiratory pressure is the main determinant of oxygenation. And D, conventional breaths should be avoided with an air leak. And the answer is, can't remember the number, C, the jet pip, the peak inspiratory pressure mostly determines the ventilation. So going up on the pip will improve getting rid of your carbon dioxide. The jet pip, which actually we set on the conventional ventilator because you always have to have a conventional ventilator working alongside with a jet because it's the conventional ventilator that provides the pip, that is mostly going to affect the oxygenation because the pip, as you all know, is a very big determinant of the mean airway pressure and it's the mean airway pressure which affects oxygenation the most. Obviously, the jet is a high frequency ventilator and yes, if you have an air leak, you definitely want to avoid the side breaths or the intermittent breaths given by the conventional ventilator because those breaths when they're given by the conventional ventilator are actually exposing the alveoli to a lot more pressures than what the jet is actually delivering with its regular pip because the regular pip given by the jet is really dampened down by the time that it reaches the alveoli. So only give side breaths when you're trying to recruit alveoli and do it for as briefly as possible. Do not use side breaths if you have an air leak. Question number 12, which of the following is true about high flow nasal cannulas? A, it provides a CPAP pressure similar to the flow rate. So if you are getting four liters per minute, then it will give a peep of four centimeters of water. B, you can dial in oxygen at 21 to 100%. C, air is heated to 25 degrees or 77 degrees Fahrenheit. And D, it causes more nasal trauma than babies that are on CPAP. And we've already been over this, the answer is B. You can determine whatever level of oxygen that you want to give between 21 to 100%. Again, whatever you're dialing in is not what the baby is receiving. And like we said, there are graphs to determine exactly how much oxygen the baby is actually getting. The air is heated to the baby's body temperature, not to 24 to 25 degrees. It's heated up to like 34 to 37 degrees Celsius. And obviously because the prongs that the babies use for the nasal cannula are not as tight, by definition, we want them to be much looser, then these prongs generally cause a lot less nasal trauma than the CPAP ones do. Also, generally, babies on high flow nasal cannula are less likely to get pneumothoraces as well. As we've already talked about though, however much flow the baby is getting, the amount of pressure that that's delivering is definitely less than that number. So if the baby's on six liters per minute of flow, the baby's getting less peak than that, maybe three, four. That also really depends, like we keep saying, on how tight the prongs are, what the flow is, how big the baby is. Number 13. The following are good signs that an infant is successfully intubated, except A, the CO2 monitor, the PD cap changes color. B, the heart rate increases. C, breath sounds are heard in the left upper quadrant of the abdomen. Or D, the observation of the endotracheal tube passing through the cords. And the answer is C. Usually the stomach is located in the left upper quadrant of the abdomen. So if you can hear breath sounds or you can hear air gushing through when you are kind of, you know, giving positive pressure ventilation, then the ET tube has a high risk of being into the esophagus and we should remove it. If the baby's properly intubated into the trachea, then we should be hearing bilateral breath sounds. As we always say, the most reliable indicator of an intubated baby, at least in the delivery room, at least if the heart rate is low, is seeing the heart rate come up. And that's often one of the first things that can happen. So the heart rate increasing, watching the ET tube go through the cords, having a PD cap turn from purple to yellow and also seeing mist in the cords or kind of like the vapor from the lungs. These are all very good signs that the baby is intubated. Question number 14. A colleague in the NICU describes the following x-ray tube. Well expanded lungs, perihelis streaking in a sunburst pattern and fluid in the right fissure. What disease process does this sound like? A, TTN or transient tachypnea of the newborn. B, RDS or respiratory distress syndrome. C, meconium aspiration syndrome or MAS or D, pulmonary interstitial emphysema or PIE. And I know you know the answer for this. The answer is A or transient tachypnea of the newborn. As you all know, the pathophysiology of transient tachypnea of the newborn is that the baby hasn't got rid of its fetal lung fluid in time. Normally about a third of that starts going away before the baby is actually delivered. A third of it as the baby's being delivered and then a third of it after the baby cries a lot after delivery. So if any one of those things goes wrong, the baby's not crying or the baby never had labor. It was just a repeat C-section or it was a C-section and so there wasn't any kind of stress associated with the delivery, then these babies are at increased risk of TTN. And what we classically see on the x-ray are these findings of just kind of increased fluid everywhere. So those are all classic markers for TTN. And that's it. I hope that was helpful for you. There are like thousands of these questions that we could do and I really tried to kind of pick and choose. I realized I didn't really go over the oscillators or conventional vents that much. So we can do a part two of that. If you reached this far, then please like this video. And if you are interested in neonatal education, then please subscribe to the channel. I hope you're all doing really well and enjoying your jobs. Bye.