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SA: Hello, and welcome to Master the MRCPCH. In this series, we tap into the expertise here at Great Ormond Street Hospital to give you an overview of a topic on the RCPCH exam curriculum. So whether you're revising for an exam or just brushing up on a need to know topic. Hopefully this podcast can give you the information that you need.
I'm Dr. Sarah Ahmed, a paediatric registrar and the current digital learning education fellow here at GOSH.
In today's episode, we're going to be talking with Dr. Alexis Bouvier, a consultant in general paediatrics at Great Ormond Street Hospital. We're going to be talking about neonatal jaundice, covering epidemiology, pathophysiology, investigation, and management.
Alexis, thank you so much for talking with us today.
AB: You're welcome. It's nice to be back. Feels like ages.
SA: So, thinking about jaundice, what would you like people to get out of listening to this podcast?
AB: So I want people to recognize or to appreciate that jaundice is very common in babies, to be able to understand when and how to investigate it, how to manage it, and possibly most importantly, when, how to reassure parents about it.
SA: Yeah, I think all of those things are really important and hopefully things that we can cover in the next 20 minutes or so. Because it does feel like neonatal jaundice is really common, something that most of us see on pretty much a very regular basis. Do we have a sense of how common it actually is?
AB: More common than not. So probably about 60 percent of your term babies and even more, 80 percent of your preterm, your under 37 weeks gestation at birth babies, will get some form of jaundice. Now, most of those will self resolve without needing any treatment. And I wouldn't be recommending any routine testing for jaundice unless you're worried about jaundice, except we generally might do a baseline bilirubin if they're being admitted to neonatal intensive care, just to see where you're starting from.
SA: We'll talk a little bit more about measuring jaundice in a little bit but before we get onto that, are there some babies that jaundice is more common than in others?
AB: Yes, so as mentioned for premature babies, essentially their livers aren't fully ready to tackle all the haemolysis that we'll get to. The low birth weight babies, sort of a similar kind of angle, breastfed babies, and that's often because of the essentially chemical composition of the breast milk that they're getting. And finally, those who have had either a ventouse or a Kiwi, sort of suction birth, or a forceps birth. And that's because that little bit of extra subcutaneous soft tissue trauma that happens can cause a little bit more haemolysis and bruising and breakdown of blood cells that then lead to jaundice. So it's probably the ones that we see most often.
SA: You mentioned the liver there and we should talk about this, but what actually does cause jaundice?
AB: So essentially baby's blood cells are going to break down by themselves as new ones are being created, and that's normal. However, in neonates the bilirubin that is released from the breakdown of the red cells, their liver isn't always as mature as we would like it to be, especially in the preterms and the low birth weight babies, and therefore isn't ready to tackle and process all of the bilirubin that can sometimes be released. Normally, that bilirubin would be processed, you'd get it into the urine, into the stool, and it would be less so in the blood. However, in babies, you get more of it sitting around unconjugated in the blood, your bilirubin level goes up, and it shows when you start to look like one of the Simpsons characters.
SA: Does the level of yellowness correlate to the level of jaundice in a baby?
AB: Not enough to base your judgment on it. There is probably anecdotal, sort of old wives’ tales of, if you've got it in the eyes it's worse than if it's in the skin. And, and there probably is something to that. However, I think the safest approach is if you've considered this baby maybe looks a bit jaundiced, if that thought has crossed your mind or inserted there by parents or by midwife or by any anybody else, check. It can be really tricky to judge how yellow a baby looks, especially when you consider different skin tones. So for example a pale white Caucasian baby might look very jaundiced, whereas it may only be visible in the sclera of the eyes in darker skinned babies, for example you Black or Afro-Caribbean populations. Then you’ve got to factor in whether you’re relying on artificial hospital lighting, if you’re trying to avoid waking people up in the middle of the night on your postnatal ward round etc. It's really best to get them in the bright daylight to get as true a picture of what you think their skin looks like. But essentially, if you've thought about it, check it. It's a fairly quick and easy one to do and it will save you a lot of trouble afterwards.
SA: Yeah, absolutely. And do you have a way of classifying neonatal jaundice?
AB: There are two main ways of classifying it. One is whether it is conjugated or unconjugated. And that comes back to what we were talking about with regards to the liver. So when the bilirubin goes through the liver, normally it would get conjugated and then pass off into the urine and pass off into the stool. However, in babies, most of it ends up being unconjugated, which is normal. So in that sense, that's a reassuring one, but that is the one that will give you jaundice, mainly. So to do that, you have to, instead of just requesting a total bilirubin, which is your standard result that you'll get if you don't request anything different, you'd have to request a split bilirubin, and it will give you the difference between the conjugated and the unconjugated.
The other way of separating it in neonatal jaundice is whether it's high enough to need to do anything about. And for that, we've got our threshold charts for phototherapy courtesy of the NICE guidelines and they're very easily available online, as well as on various apps, including Billiapp, which is one that I used to use when I was doing neonates.
SA: Yeah, absolutely. And thinking a little bit about how you're separating it, are there any red flags that you need to be aware of that might make you more concerned about a baby that presents with jaundice?
AB: Definitely. Jaundice under 24 hours of age at first presentation, i.e. if somebody's noticed it before the baby's one day old, is a problem until proven otherwise. You've got to be thinking about things like infection. One would hopefully already know whether the baby had any risk factors for sepsis, so being born premature, mother's waters having broken for ages, mum having had a, an infection within the first 24 hours, those kind of things. The other one that's a big red flag is if the baby's neurology is abnormal. So handling badly, floppy, jittery, stiff, abnormal posture, poor suck, anything that would make you think about an encephalopathy, including leading up to seizures. But obviously for babies having seizures, that's going to be worrying you regardless, but those would be the main red flags for neonatal jaundice.
SA: Yeah, definitely things for people to keep in mind when they're approaching these babies.
You spoke about the threshold chart, so we should talk a little bit about how you would measure levels of jaundice in a baby.
AB: Generally we use blood tests. You can measure it with transcutaneous bilirubinometers, or TCBs. Essentially, you press something against generally the forehead of the skin, it goes beep, and it gives you a number. Not everywhere has those, unfortunately for us, we have to keep heel pricking babies, and unfortunately for the babies and the parents. But depending on where you work, the community midwives or even the hospital midwives and postnatal wards may have them. It's important to remember that TCBs aren't reliable under 24 hours of age, if a baby is born at under 35 weeks, or if a baby has already had phototherapy. So if a baby's gone home, having had phototherapy, and the midwife comes by and tries to do a TCB, for example, you can't do that. Same if you're in a postnatal ward and somebody's thinking, Oh, they're jaundiced at 23 hours, you can't do a TCB.
Another thing to consider with the TCBs is they become less reliable results wise, the higher up values go. So if you've got a TCB saying 110, for example, it's probably in the a 100 to 120 range. If however, the TCB says 260, 270, 280, anything over 250, it's not as reliable. And the difference between what it's saying on the measurement and what the blood test result actually is, the true level, could be quite a bit, and that could make a difference as to whether your baby needs treatment or not. So, if you've got a TCB over 250, then they would need to come in to hospital to have a blood test or if already in hospital, you'd have to do a blood test as well as a TCB. But the main way we check is through what we would call a serum bilirubin or SBR is generally how we would refer to them. These can be heel pricks and generally are and depending on where you work, on NICUs or on postnatal wards, you can often do what's called a spun bilirubin. You put it in a machine, it lasts for about 5 minutes or so, and it separates out into the yellowy plasma section, which will give you the bilirubin reading, and then the redder haematocrit section, which will give you the PCV or haematocrit range for that as well. Or gold standard is you'd send it to the lab, especially if there was any concern that the spun bilirubin or TCBs weren't giving you what you expected or weren't giving you true results. The lab would be the best one to do. For example, you can sometimes get, if you might get a 10 percent difference between your gas machine bili, and that's one I didn't mention, you can also sometimes get a bilirubin on a gas, depending on your local machines, but if there's a big discrepancy, you go with the lab result, whether that's what you wanted it to be or not.
SA: Yeah, it's always a bit of a, a heart sink when the lab result does not match up with the gases that you've just spent the last however long doing.
So you've done your blood test, you've plotted it on the appropriate graph that corresponds to the right gestation and you've double checked that. How would you then go about managing jaundice?
AB: So you stole my thunder there with a bit about the appropriate aged Bilirubin chart, because it is really important and that is really key. The thresholds for phototherapy or exchange transfusion differ depending on the gestation of the child, especially in that first sort of three, four days. So it's really important to determine when your baby was born, including what time your baby was born, because as you plot it, along the bottom of the chart is time and days from birth. So when did you take your sample? Not when the result came back, especially if there's a delay in the lab, but when the sample was taken, this baby was X days, X hours old. This is where the number is. Does it fit on above the line for any particular treatment?
So if you're, if it's hit your treatment line for phototherapy, then you should be starting your phototherapy within four hours. This baby has jaundice, the treatment is phototherapy, crack on with it. We shouldn't be seeing massive delays. If necessary, you bring one down from neonatal intensive care to A&E or find one, but we should be pushing to get that started ASAP.
If, however, the treatment line has not been hit then you sometimes use a little bit of discretion depending on how close it is to it. So if it's within 10, and generally that's called one box, one square. If it's within 10 of the treatment line, you'd often start and then check a little bit later and, and the baby might just not need very long on it. If however, it's well below, five, six, seven, eight boxes below, then your baby probably doesn't need it repeating, let alone needing any phototherapy starting. And similarly, if it's close to, but not quite on the exchange transfusion line, then you may start getting the exchange transfusion stuff ready whilst you're whacking them with multiple lights, hoping that you can then avoid the exchange transfusion.
SA: Before we talk about exchange transfusions, can you tell us a little bit about how phototherapy works?
AB: Yeah. So phototherapy works with a specific wavelength of light, of ultraviolet light that goes through the skin and breaks down the excess bilirubin that's floating around. And I mentioned specific wavelength. Because often you will hear from parents, from midwives, from health visitors, from the internet, from wherever, just put your baby in the sun and that will cure the jaundice. And yes, the sun does contain that specific wavelength that we want. However, it also contains all the other wavelengths that aren't particularly useful. And to get enough of the correct one, you basically have to sunburn your baby to a crisp, so it's not actually what we want to do. The only thing that can really be done at home to either reduce the chances of jaundice or manage mild jaundice, for example, is feeding baby. Underfed babies get dry, get crispy effectively, and are more likely to be jaundiced, which is why we see it so much more frequently in the exclusively breastfed babies, to the point where you'd often find the common combination of weight loss, jaundice and hyponatremia or high sodium with reduced wet nappies and poor hydration, et cetera, because the baby's just not getting enough milk.
SA: Yeah, that dreaded combination of the high sodium and the jaundice levels.
AB: Well, a dreaded combination, but feed the baby and everything tends to get better. Plus or minus a bit of phototherapy along the side. At this point, I think it's important to mention that some parents may be quite opposed to suggestions of even temporarily using bottles, either to give extra top up in underfed, exclusively breastfed babies, or to minimise time out from under the lights. It's not unheard of for this to be a bit of a tricky chat, in which case, don't hesitate to ask your senior for support. Sometimes we find that parents would rather a temporary NG tube than a bottle. At the end of the day, it's about how much gets in without impacting on phototherapy treatment time. So it's crucial to have a clear feeding plan in place. Essentially, how much milk, how often.
*trumpet noises*
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SA: So let's say that the jaundice is particularly high. You mentioned exchange transfusions, which happen quite rarely I feel now compared to in the past because we're so good at picking up jaundice and treating with phototherapy. But what is an exchange transfusion?
AB: An exchange transfusion is where the baby's got so much excess bilirubin floating about in their blood that you literally need to take blood out of them and give them unbilirubined blood back in to drastically reduce the bilirubin load. Your local neonatal intensive care, and this would have to be done in neonatal intensive care, both because of the monitoring that it requires, the central access that it requires, the time and staffing that it requires. Your local neonatal intensive care will have their policy of volumes and timings and monitoring and such like that. So, please go and look up your guideline and speak to your friendly neighbourhood neonatologist.
But generally what we do is what's called a double volume or double circulating volume exchange. So if you consider that a term baby might have 80mls per kilo of circulating blood volume, we're going to be exchanging twice of that, so 160mls per kilo to aim for a 50 percent reduction in their total bilirubin. It is going to be slow. We do, for example, at Great Ormond Street, it's five mls over five minutes, one ml per minute that you're doing. And often you're putting in through a pump at one ml per minute and taking out by hand at one ml a minute, which is tedious and prone to errors, which is why you often do this as a pair with one person doing it and one person documenting it. So you're constantly double checking to make sure that you're not going too fast, not going too slow, and that you're not losing track of how much you've taken and how much you've put in. Cause this might take up to about three hours in total for you to do this as. This is your morning done. This is you handing over the bleep and making sure you've eaten, sorted yourself out properly beforehand. And these babies would need a generally an umbilical venous catheter to insert the blood and then an umbilical arterial catheter or UAC to withdraw the blood.
So it doesn't happen nearly as often as it used to. That's correct. Because we're better at recognizing. We've got the ability to do quick serum bilirubin checks, spun bilis. We've got more access to phototherapy, whether that's bili blankets, where they effectively lie on a fancy sheet or standard overhead lights, think of it kind of like outdoor garden heating lamps. And again, whether that's single, double, triple, i.e. the total number or strength of lights and/or blankets that you're using at any one time. Sometimes even quadruple lights, if you're getting close to that exchange transfusion line.
SA: And things I would say is make sure that the lights are set up properly, make sure they're not miles away from the baby. And make sure that the baby's undressed as much as possible below the lights, because if you have a baby underneath the lights wearing a baby grow, the wavelength isn't going to hit the skin and it's not going to make a difference.
AB: Absolutely. Eye mask and nappy only, get cracking and minimize interruptions. The treatment is phototherapy. Every time you take the baby out for cuddles, you're not treating the baby and surprise, surprise, the bilirubin's not coming down. But around that, it's important to appreciate the difficulty for parents to not be able to have that regular contact with their baby. But for the good of the baby, sometimes it's best to give them bottles or sometimes even NG if parents just want to breastfeed so that they can stay under the lights and get treated as quickly as possible.
SA: A hundred percent. Um, so you've started a baby on phototherapy. How long do you leave them under there for? And when do you next check a bilirubin?
AB: So you would next check for bilirubin about four to six hours after starting. And ideally, you would start to see it coming down nicely. If the bilirubin was staying static, and definitely if bilirubin was still going up, you'd be thinking about escalating from, say, single to double, double to triple lights. And in fact, if it's going up by almost a box per hour, then you might be thinking about, actually, is there something else going on? Some ABO incompatibility, for example. Do we need to be considering an exchange transfusion? And that reminds me about one thing I forgot to mention earlier. If you're starting a baby on phototherapy, it's good practice to check their full blood count. To make sure that they haven't haemolysed so much that they're becoming borderline anaemic, and also to check their what we call group and DAT or group and DCT, depending on where you work, essentially how their blood group is compared to their mum's blood group and whether there's been any suggestion of an autoimmune interaction that might be triggering and causing this haemolysis.
Once you've got the baby on phototherapy and it's going in the right direction, you would check it say every six to 12 hours. Not excessively frequently, but at least once per shift.
Of note, don't be surprised if darker skinned babies take longer for their levels to drop, that's because their dark skin tone actually protects against UV radiation, including the specific wavelengths used in phototherapy.
Once it's come five boxes, so about 50 below, you can stop and then rebound check 8 to 12 hours later. And that's because once you've stopped the treatment, sometimes it goes back up. If it goes back up a little bit, that's okay. If it shoots back up really acutely, really high, really vertically then you may need to put them back onto phototherapy for a little bit longer.
SA: Yes, absolutely. So let's say a baby has been discharged, they've been at home for a week, a couple of weeks, and they come back in to A&E or the GP and they look a bit yellow. At what point would you be worried about those babies having jaundice?
AB: So first of all, it would depend on how old the baby was when they were born, what their gestation was. Because if you're born preterm, less than 37 weeks, we give you a little bit more time, a little bit of benefit of doubt, a little bit more leeway. And we give you until 21 days, at which point, if you're still jaundiced, we consider that prolonged, compared to 14 days or two weeks for term babies. And again, it's quite common and mostly benign. Almost 10 percent of breastfed babies will still be jaundiced visually to some degree at almost a month old, even though there's nothing else going on with them, but 14 days in term, 21 days in preterm would be our threshold for at least having looked at it.
SA: And is prolonged jaundice more likely to be conjugated than unconjugated?
AB: No. Most prolonged jaundice is still essentially physiological. It will be unconjugated and the more red flags there are the more likely it might be conjugated, but that's why we do a split bili as our core test. Basically, you check their total bilirubin level, including their conjugated and their unconjugated. And mainly you're looking for the conjugated aspect. If their conjugated is over 25 or generally over 10 percent of their total, that's potentially cause for concern, especially if that's associated with any signs or symptoms in the history and the examination, such as pale stool, often your white chalky stool and or dark urine. And that's essentially because, normally the liver should be transferring that processed bilirubin into the stool, giving it the dark pigmentation that we normally see, and out of the urine, therefore, keeping it relatively clear as long as the baby's well hydrated. But if you've got something like biliary atresia, which is probably your number one thing you're trying to rule out, in a prolonged jaundice screen, where you literally cannot pass that bilirubin through because you haven't got the biliary tree for whatever reason. It all sits in the liver, it all backs up into the blood, baby remains jaundiced, despite it having reached the liver and started to be conjugated. And instead it doesn't go into the stool, it goes into the blood and the excess passes across into the urine. You'd also be asking about things like family history, blood disorders, thalassemias, anaemias, previous jaundice requirements for phototherapy, considering things like G6PD. Depending on where you work, some places might automatically do a G6PD and a full blood count and sometimes a thyroid function to check for underactive thyroid. Although that's usually checked for on the guthrie test at day five anyway, the heel prick.
Finally, urinary tract infection, or UTI, is a common cause of prolonged jaundice that we shouldn't be missing, especially since we'd have a low threshold for treating infections under three months old with IV antibiotics, as well as arranging imaging, etc.
So, essentially, you do a split bili, you look at the weight, you consider the feeding, you talk about and look at the nappies and you send off a clean catch urine culture. Those are the core bits of a prolonged jaundice review.
SA: And every hospital will have their own pathway for dealing with prolonged jaundice, usually that involves bringing them back to a clinic somewhere at some point.
Let's wrap up with some quickfire questions. So firstly, are there any exam questions that could pop up about jaundice?
AB: Yes, I think the two big ones that I might expect to see would be a presentation of prolonged jaundice with abnormal nappies. So your pale stool, your dark urine, for example. And then you'd have to be considering biliary atresia and know to request an urgent ultrasound and know why you're doing it because you want to get there within the first 4 to 6 weeks to be able to do the surgery otherwise you start to lose the benefits and you start to veer uncomfortably in the mortality morbidity direction. But effectively, that's a standard prolonged jaundice approach, but knowing why you're doing it and recognizing the red flags.
Another one would be possible genetic causes or familial causes of jaundice, things like G6PD, hereditary spherocytosis, where essentially the walls and the formation of the red cells aren't as good as we would like them to be, and therefore they're more at risk of haemolysis, or haemolytic disease of a newborn, where you've got such a degree of either ABO or rhesus incompatibility between baby's blood and mom's blood. Mom's antibodies effectively attack baby's blood, massive haemolysis, anaemia, and nasty jaundice. Those would probably be the main ones I would expect to see. There are some syndromes that can be associated with jaundice, including conjugated jaundice things like Alagille Syndrome, that you might see more in your genetics chapters or genetics based questions, but probably prolonged jaundice and biliary atresia or some of the common hereditary familial stuff like G6PD and hereditary spherocytosis.
SA: So second question, and I'll make sure everything is linked in the description box below, but are there any resources that you would recommend?
AB: Yes, the NICE guidelines on jaundice are some of the nicest and clearest, no pun intended, that we have. It's for under 28 days. So that whole sort of first month neonatal period. Your local hospital guideline is what I would direct anybody to as to how you test, how you manage phototherapy, whether it's a blanket, whether it's lights, et cetera, your exchange transfusion processes. And then if you are working regularly with neonates, whether that's on NICU or on A&E, then having an app like Biliapp, for example, so that you can input the numbers, the time of birth, the time of result, the level of result, the gestation, and then it will chart it for you and be able to plot whether they do or do not need phototherapy. Practicing being able to do it on the papers on the paper forms is a good skill to have.
SA: Yes. And you can download the paper forms really easily and print them out. And there's always a stash of them somewhere on the neonatal unit or in A&E.
And so finally, what are your three takeaway learning points?
AB: So I'm going to be a little bit cheeky as usual, because I struggled to fit in three. It's common, especially in the breastfed and preterm babies. If you think about it, test it. Don't just go by how yellow or not they look, especially with the darker skin babies. If they need phototherapy, start it early and do it properly. So don't wrap them up in clothes, don't let them spend ages out for cuddles, et cetera. Keep them under the light, get the treatment done and then get them home faster. And finally remember the different thresholds for prolonged jaundice screening in term versus preterm. So that you don't worry too early for the preterm ones and you don't leave it too late for the term ones for that simple split bili plus or minus other tests.
SA: Yes, all very important takeaway learning points. Alexis, thank you so much for a really comprehensive overview of something that we see alarmingly regularly whilst practicing paediatrics. So thank you.
AB: You're welcome.
SA: Thank you for listening to this episode of Master the MRCPCH. We would love to get your feedback on the podcast and any ideas you may have for future episodes. You can find link to the feedback page in the episode description, or email us at
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