Cyanotic congenital HEART disease? STEP-by-STEP work up

It is so great in those situations when somebody has put like a little card on the back of the baby's crib saying my face is bruised so then I can do the rest of the exam and comfort and the baby's okay. Hello, welcome to Tala Talks NICU. I'm Dr. Tala and on this channel we break down medical concepts and make them really easy for you to understand. So many of you have asked us to cover cardiac issues in the neonatal period so that is what we are going to start today. Before I continue I'm going to ask you to like this video and to subscribe to this channel if you're interested in neonatal content. Let's start with a case study. Let's say that you are called at 12 hours of life because there's a baby who's still in the room with his mommy, a full-term healthy baby that appears cyanotic. So you find out that the baby is now 12 hours old and was born by c-section. The mother is gravida 1 and it was a c-section because the baby was suspected to have macrosomia so suspected to be large. You also know that the mother was a type 1 diabetic and has had diabetes for five years. What do you do next? Okay, what you actually do is go right away drop whatever you're doing whether you're examining a baby or whether you are eating lunch obviously if a baby's sick then probably don't drop that but you should go and evaluate a baby that appears cyanotic immediately. While you're wandering over there you should be thinking about Cyanosis as you all know is when a patient or in this case a baby appears blue. For whatever reason because it's us judging it it should be a really subjective concept but for some reason we all seem to really agree on when a baby appears cyanotic and interestingly everybody views a baby as when that baby has about five grams per deciliter of deoxygenated hemoglobin. Let me break this down further what that means is when a baby has a high hematocrit or is polycythemic that baby will appear cyanotic at a much higher saturation level than if the baby is anemic. So let's give two examples of this. Let's say in the first baby the baby has a hematocrit of 60 which is a hemoglobin of about 20 remember it's kind of three to one so if you have a hemoglobin of 20 then say you are satting 75 percent if the saturation is 75 percent what's 75 percent of 20 or three quarters of 20 that means that baby has 15 grams which is 75 percent of 20 of oxygenated blood and has five grams of deoxygenated blood so that means that a baby with a hemoglobin of 20 satting 75 percent will appear cyanotic because they have their five grams of deoxygenated hemoglobin. Now let's talk about another baby with a hemoglobin of 10 which is kind of about a hematocrit of 30 so when that baby has a saturation of 50 percent that baby will have five grams of oxygenated hemoglobin which is 50 percent of 10 and five grams of deoxygenated hemoglobin so for a baby with a hemoglobin of 10 which is like we said about a hematocrit of 30 that baby would have to be satting 50 percent to look cyanotic so you can kind of get from this that the lower the hematocrit of a baby the lower the saturations need to be for a baby to appear cyanotic which is kind of really scary if you think about it the really anemic baby will take a lot more to appear cyanotic and obviously those are the babies that you're going to be most worried about because they're definitely not getting the oxygen that they need to their cells of their body. The other thing that I want to talk about now is acrocyanosis which is a completely normal thing in a baby and you've all seen it and that's when the baby's hands and feet especially kind of in the first couple of days after life but honestly it can continue for a few weeks they can appear really bluish almost purplish and that is completely normal most of the time because it just indicates that they've got kind of increased vasomotor tone in their extremities they might be a little bit cold but this is something that can happen very often until like their responses become a lot more robust and then a third big differential of cyanosis is just bruising and this is especially true with bruising of the face because honestly that's really where we're looking for the cyanosis the most kind of in the lips and the and the inner mouth area because then you can definitely differentiate it from the acrocyanosis which can be very normal in babies so if a baby's face is really bruised especially if they were delivered op or kind of like sunny side up then that can really look like cyanosis and i've walked into so many newborn babies rooms and kind of like gulped really worried that we've just been missing a cyanotic baby for the last few hours um and then i go on to find that the baby's face is just bruised it is so great in those situations when somebody has put like a little card on the back of the baby's crib saying my face is bruised so then i can do the rest of the exam and comfort and the baby's okay and while we're on cyanosis i'm just going to go through this as well because it's something that we talk about a lot in the unit and that's the concept of a differential cyanosis and that is where basically the upper extremity especially the pre-ductal area which as you all know is the right arm this is kind of the pre-ductal area is much higher saturation than the post-ductal area so normally we check that on the legs and as you probably all know that's the basis of the cchd exam that we do you would get a differential cyanosis any time the ductus is supplying blue blood to the lower extremities so for example it could happen in pphn when you have the high pressure in the lungs kind of pushing that blue blood down the ductus which then goes ahead and gives blood to the legs or you could have it in for example an interrupted aortic arch where pre-ductally the left ventricle is giving blood to the right arm but post-ductally the blood is coming from the right side of the body which is blue blood so those are kind of like very classical situations where you could have differential cyanosis reverse differential cyanosis is much more rare or rarer which one's the word is rarer anyway much less common a reverse differential cyanosis and that is when you have a lower oxygen saturation in your pre-ductal so really the right arm versus in the legs so for example on your right arm you could have an oxygen saturation of like 72 and your legs have an oxygen saturation of 85 this is very typical for transposition of the great arteries i'm going to do a whole video on that later so i'm not going to go through why that happens now but if you see a significantly higher oxygen saturation in the legs than the arms then be thinking about a tga actually be thinking that there could be something wrong with the perfusion and the pulse oxys and whatever but if you're definitely certain that that's accurate then that's what you're worried about right so you're still walking to this patient's room and you're thinking about all these things of cyanosis the other thing that you should be thinking is what is the differential diagnosis of cyanosis what can cause cyanosis and this basically falls into three big categories the airway your breathing and then your circulation so let's go over kind of some of the important aspects of all of those right so a let's start with airway issues and obviously if you have any sort of obstruction to the oxygen getting into the lungs then you're going to have cyanosis so that could be anything like pierre robin sequence where you have like a really small chin it could be that you have something wrong with your larynx so you could have like a paralyzed vocal cord or really bad laryngeal malacia you could have something wrong with a trachea so like a tracheal stenosis or tracheal atresia or you could have something kind of pushing on the whole airway like a huge neck mass so obviously anything that kind of stops the oxygen getting into the lungs is going to cause cyanosis the second category is breathing so think of all the kind of classical diagnoses that we have rds meconium aspiration syndrome pph and anything that's obviously going to interrupt the oxygen getting into the blood from the lungs you know other structural abnormalities like a cdh or a cpam or eventration of the lungs are also going to end up with cyanosis also if a baby is hypoventilating so just not taking deep enough breaths then that could also cause cyanosis so if a baby has really bad a's and b's or has really bad hie and is just out of it and not breathing deeply or a baby has sepsis then those are obviously going to be associated with cyanosis as well and then the c part of the mnemonic for abc of cyanosis is circulation so either something is wrong with the blood so you have way too much blood in polycythemia normally hematocrit of kind of 65 70 75 where the blood itself can become really sticky and actually like just not carry the oxygen around the blood remember as well if you do have a really high hematocrit then it's not going to take a very low saturation to appear cyanotic so you can have cyanosis from polycythemia or anemia or met hemoglobinemia which can happen in the unit especially if a baby is on ino and then the big one why we're all kind of here is the circulation when you have cardiac abnormalities and these are kind of considered the cyanotic congenital heart diseases and we will go over all of those in the next video the two most common cyanotic congenital heart diseases are the tetralogy of fallot as well as tga and just realize for now that a baby will appear cyanotic from a congenital heart disease if the blood is not getting to the lungs so if the blood is not getting to the lungs and the lungs are unable to give it oxygen then obviously that baby is going to appear blue so that's one reason that a baby may appear cyanotic the other reason the baby may appear cyanotic is if the blue blood is mixing with the red blood so it kind of ends up with purpley blood or cyanotic blood so that is why a baby is going to appear cyanotic with a congenital heart disease right so you're wandering over to see this patient and just before you go in you see the lnd nurses who have been taking care of the postpartum nurses that have been taking care of this baby and as you're going in you ask about history and obviously you want to know any risk factors that may predispose this infant to having any sort of diseases or in this case let's go down the pathway of are there any risk factors to heart disease in a baby the truth is that most of the congenital heart diseases that happen in fetuses happen completely sporadically so just bad luck with how the heart is being formed so it isn't that cup of coffee that you had in the second trimester it's not that glass of wine that you had before you found out you're pregnant or the marathon that you ran it's just really bad luck with something happening as the heart was forming there are some risk factors and probably the strongest risk factor is having a previous congenital heart disease in a family member especially the mother or a sibling of the infant that you have in fact if a sibling has a congenital heart disease then your patient has a two to six percent chance of having a heart disease so honestly if i have a baby in the unit and the mother tells me that the older sibling ended up needing surgery for a heart disease i will go ahead and get an echo on that baby other risk factors for congenital heart disease are if the mother was diabetic especially pre-gestational diabetes like we have in this case study she had diabetes for five years type 1 diabetes for five years also if the mother had viral infections rubella is the one they always ask about on exams if the mother took any medications the there's a huge association between the mother taking lithium and ebstein's anomaly that's the huge board question or if the mother ingested a lot a lot of alcohol during pregnancy and then about 15 to 20 percent of cardiac anomalies are associated with chromosomal anomalies so kind of the most common ones are trisomy 21 trisomy 13 and trisomy 18 okay so we've got this baby's history and we know that this mother was diabetic so we're kind of thinking okay a little bit higher chance of this baby having a congenital heart disease but diabetes is also associated with an increased risk of ttn as well as even rds so we're going into this room now to examine this baby so the first thing is obviously you do that kind of quick scan over the baby and just kind of look for any malformations or any physical exam findings that may be associated with a trisomy or obviously if the baby's got a huge neck mass or the baby appears downs then you're already going in one direction so just that initial huge scan during your physical exam obviously you got called to see if this baby was cyanotic so really as you're looking over the baby you're thinking is this baby really blue or not and hopefully somebody's kind of running around trying to get a pulse ox on this baby then you continue down with the respiratory exam does the baby have any increased work of breathing is the baby grunting are there subcostal retractions that would probably make you go more in the direction of a respiratory issue does the baby have tachypnea which means is the baby breathing rapidly and i just want to talk about that for a second as well so tachypnea especially quiet comfortable tachypnea kind of remember those key words is very common in babies with cyanotic congenital heart disease because what happens when you have heart disease it basically means that the cells in the body are not getting the oxygen that they need so what happens when cells don't get the oxygen they need these cells end up converting to anaerobic metabolism which as you all know results in an increased buildup of acid so these babies will end up with a metabolic acidosis so what does the body try to do to kind of equalize that acid it tries to create a respiratory alkalosis so how do you do that by breathing rapidly because by breathing rapidly you can blow out the carbon dioxide and having a low carbon dioxide in the body is basically what a respiratory alkalosis is so these are babies whose ph may not be like 7 or 6.9 because they've had a good response from the lungs and because there's probably nothing wrong with the lungs they're not going to be kind of breathing hard or really pushing themselves they're just breathing rapidly but with no real extra effort so that's why it's quiet comfortable tachypnea so if you see quiet comfortable tachypnea and cyanosis then you should really be going down the direction of this being a cardiac lesion whether it's clinically or whether it's on an exam then obviously you have to concentrate on the cardiac exam so you listen to the heart sounds you listen for murmurs a huge huge caveat here there are many congenital heart diseases that will not present within a murmur at all so like an interrupted aortic arch a hypoplastic left heart even a tga might not have a murmur depending on the size of the outflow obstruction and tof you might not have a murmur so just because you don't hear a murmur it doesn't mean that this isn't a congenital heart disease that was a really bad double negative so i'm going to rephrase that you can have a congenital heart disease even if there's no murmur in every single exam you should be checking for femoral pulses obviously if you have like an interrupted aortic arch or a hypoplastic left heart syndrome then those pulses are going to be a lot weaker so every exam on a neonate should involve feeling the femoral pulses they really can be very indicative of a lot of diseases so get used to feeling them and then obviously make sure that you're checking the perfusion make sure that there's good cat refill and this baby is not going into shock which along with cyanosis is just not good at all while you're in the room make sure that you do ask the mother how is the baby being feeding is the baby being really lethargic which is always really difficult to tell in the first couple of days of life because babies are either kind of cluster feeding or just sleeping the whole time so that might not add a lot to the history and it's very unlikely for a one to two day old to be sweating at this point it's possible that they have issues with sweating when they're kind of three four months old and they do have a congenital heart disease but right at this stage of life it's very unlikely for that to be happening then make sure that you finish the rest of the exam and hopefully by this time you will have a pulse ox reading so this will kind of confirm whether baby really does have cyanosis or not or whether the baby is desaturating or not because cyanosis is a clinical finding so you put the pulse ox on and you see for example that the baby is sat in 70 that means that you know this is the blueness is definitely correlating with what you're seeing on the pulse ox like we said earlier you should also do a pre and a post-ductal sat because that might kind of sway you in one direction especially and i'm going to repeat this if you see a lower pre-ductal sat than a post-ductal sat then you are all worried about tga in fact doing a pre and post-ductal sat is the basis of the cchd screening that we do really in all babies at 24 hours of life and the point of the cchd screening is to pick up those babies that we haven't realized are cyanotic or may have a congenital heart disease that we haven't necessarily picked up on so at 24 hours of life in all babies we'll put on a pre and post-ductal pulse ox if the baby saturations are less than 95 percent in both extremities or there's a difference of more than three percent between the upper and the lower extremities then this is considered to be a screen so depending on just how bad it is and how low the sats is either you have to repeat the screen or just go ahead and get the ultrasound of the heart anyway so this should be done on all babies but especially in babies that you think are cyanotic or may have a congenital heart disease right so at this point you've figured out that this baby is indeed cyanotic the baby has comfortable tachypnea but otherwise looks very well you take the baby back to the NICU and at this point you try to figure out what you should be doing next in reality as you all know you're probably kind of doing all of these at the same time but I'm going to kind of go in an order so one of the first things that we would want to do is a blood gas preferably with a lactic acid so what may you expect to see on a blood gas especially kind of an arterial one is what you want to see is because you do want to figure out what the PaO2 is on probably room air but what you may also see is a metabolic acidosis so maybe a bicarb of 12 and a base deficit of like minus 9 or whatever but you might see a compensatory respiratory alkalosis so this might be a baby that we have a gas of 7.2 30 and then minus 9 so you've got the respiratory alkalosis trying to compensate for that metabolic acidosis the other thing that you can do especially if you can't get an echo pretty quickly is something called the hyperoxia test and that's when we put the babies in 100% oxygen for 10 minutes and then remeasure their PaO2 which if you remember is the amount of oxygen that's dissolved in blood so if a baby has a normally functioning heart then the PaO2 should probably be above about 200 generally if that PaO2 is less than 100 then you're a lot more worried about that being a congenital heart disease and the reason for that is really logical if you have bright red blood and you just give more and more oxygen you're never going to get that PaO2 really elevated if there's still a stream of blue blood mixing with it so even if your PaO2 is like 600 with a bright red blood you've still got that blue blood mixing in with it that's going to lower that PaO2 significantly so that's why the hyperoxia test is a good kind of screening test to see if this really could be a congenital heart defect another test that you could do is a chest x-ray so there's a lot of talk about like what the hearts look like on x-rays and I'll run through those just because you probably need them for your boards but honestly they're really not that helpful and I feel like so many times we have the heart diagnosis and then we look like at the x-ray and we're like oh that does look shaped so you're definitely not making your diagnosis based on an x-ray x-rays I think for me are really important for two reasons when you have a baby like this the first one is you want to make sure the baby doesn't have a respiratory disease that you're missing maybe there is a huge cdh or a c-pam or horrible rds or meconium aspiration syndrome which would all kind of be unlikely with the baby not having increased work of breathing with retractions and grunting and everything but obviously common things being common you want to make sure that you're not missing just a respiratory disease the second reason I find x-rays really helpful is to look at the amount of blood flow there is in the lungs so if you get an x-ray and the lungs look really really black like you can't even see like the little vessels then you would expect at that point that there's very little blood flow going to the lungs and the opposite is true as well if you can feel like you could literally draw out all the vessels with thick white markings of the lungs then you would suspect that there's a lot of extra blood going to the lungs this is helpful in kind of the direction of the congenital heart disease that you have and we'll be talking about this in the next video but some of the congenital heart diseases end up with not enough blood going to the lungs and some of them end up with way too much blood going to the lungs so it's helpful in that respect as a caveat though I want you to realize if a baby has pphn where there's really high pressure in the lungs those lungs can also appear really black because all that blood is being shunted away from the lungs down the ductus to the body so really black lungs can be pphn or a type of congenital heart disease where not enough blood is going to the lungs okay so let's just cover these anyway just so that you know them so the x-ray associations with the different cardiac diseases the tga kind of looks like an egg on a string tetralogy of fallot can look kind of boot shaped the tapvr can look like a snowman and this actually kind of really does look like that you've got a really prominent right atrium because all that blood is flowing in so you see kind of the head and the body of the snowman and then the one that you really can diagnose on an x-ray is an ebstein's so normally the heart takes up kind of less than 50 percent of the lung and the whole thoracic volume but in ebstein's it's basically all heart so you have this huge globular heart that's pretty much taking over all of the lungs and that really is one of the few times where you can get the x-ray and be like okay we've got an ebstein's here then you could also get an ekg it's not necessarily going to be that helpful in diagnosing anything um but depending on kind of whether it's more of a right or left sided lesion you might see kind of axis deviation and stuff and then you should probably also be getting labs making sure that this baby isn't septic checking for anemia and polycythemia as well then if you are suspecting kind of a right-sided lesion or like a tetralogy of fallot or something then um you should also be checking a calcium making sure that the calcium isn't low and this baby doesn't have the george syndrome then obviously ultimately how do you make the diagnosis with a trans thoracic echo with an echo we never do trans esophageal echoes really in the unit so with an echo which is an ultrasound of the heart so um hopefully a cardiologist will be able to read this as soon as possible but that ultimately is what is going to make your diagnosis let's say that it takes ages to get your echo but you've had like atpa o2 on the hyperoxia test you've got acidosis metabolic alkalosis um the baby's perfusion has kind of slightly decreased then if in doubt you are going to assume that this is a congenital heart disease so while you're waiting for an echo make sure that you are also supporting this baby so obviously first thing make sure that you're supporting the baby with whatever it needs from an oxygen ventilation standpoint so whether they need to be intubated the vast majority of them don't be don't need to be intubated but whether they need like a little bit of oxygen or anything else remember that if this is a mixing lesion so there's genuinely blue blood joining the red blood then it's useless giving that much oxygen it doesn't matter how much you give because it's the baby's never going to look very pink and in those situations you accept an oxygen of kind of 75 80 so just remember that if you are assuming this is a congenital heart disease and the baby is satting 80 if you put that baby on an fio2 of 100 it's going to make no difference so stop even trying stop exposing the baby to that much oxygen just allow the baby to be satting kind of high 70s low 80s if you really think it's cardiac then because you're worried that the gut is also not getting the perfusion that it needs and the oxygen that it needs make the baby npo and just put the baby on id fluids always if you can with a little bit of protein and then again if you really do suspect a cardiac defect then just go ahead and start prostaglandins or pge2 and normally we would start that in which should be mixed in kind of d5 or d10w at a dose of between 0.02 and 0.05 micrograms per kilogram per minute as you all know prostaglandins are used to keep the ductus patent so remember that pge patent ductus so you want to keep the ductus patent in a whole bunch of cardiac diseases because either it's a shortcut to get the blood into the body the systemic circulation because there's a track outflow tract obstruction where the blood can't get there or for whatever reason you need the blood to get into the lungs because something's blocking the blood from going into the lungs so keeping that ductus open most of the time can be life-saving extremely extremely rarely it could make the situation worse but that's not what you're thinking about when you have a very sick baby like this just go ahead and if you think you need it just go ahead and start the prostaglandins there are side effects of prostaglandins it can give babies a fever and it can kind of make them really flushed and it can also increase or make the baby have apnea so they just have episodes where they just stop breathing sometimes that apnea will respond to giving caffeine so even if it's a full-term baby the baby's been started on prostaglandins and starts having apneic events just try try a loading dose of caffeine sometimes that will help or if it doesn't really help then you probably need some sort of mechanical ventilation to breathe for the baby because you're not going to stop the prostaglandins if that's what you think the baby needs and then obviously especially if you're giving prostaglandins make sure that you secure IV access so preferably you want a UVC and a UAC in this baby so you can kind of follow labs and make sure that you have a very solid way of being able to give medicines to this baby right so finally hopefully you get the echo done and you'll get that final diagnosis at that point you discuss with cardiology you've probably been discussing all of this with cardiology all along whether the baby can stay in your unit or whether the baby needs to be transported out to somewhere where they can do cardiac surgery sooner or later this baby in this clinical vignette ended up having a TGA and so this baby did need transferring out to get cardiac surgery within the next few days well that was part one of kind of the introduction of the cardiac diseases I really do hope that you learned something I love the entire field of cardiology so I'm really enjoying talking about all these diseases in the meantime can you remember to like this video and to subscribe and I just want to thank you all again for being here