Pediatric Edit

Welcome back to behind the knife. And today we're going to do pediatric ab site and we have a long time favorite of behind the knife, making a special appearance to help lead us through the pediatric review. And it is the newest pediatric surgeon in the army. Dr. Woo. Doe woo. Welcome. Hey, Kevin.

Thanks. Thanks for having me, John. It's good to see you again. It's so nice to get the gang back together. really excited to kick this off. So let's just jump right in. Let's start with pediatric trauma. We know that trauma is the number one cause of death in Children. And john, why don't you start us off?

What's the best indicator of shock in pediatric patients? Yeah it's the best indicator is tachycardia. The one thing about kids that you have to know, and this works clinically as well, is that they look great until they don't. So they decompensate very quickly. But the first thing you're going to start to see is that heart rate creeping up.

Absolutely. They're able to compensate all the way up until the point that they don't. And so tachycardia is what you're watching for.

And so Kevin, do you want us to, do you want to take us through the tachycardia by age group general rules of thumb for what's considered normal range?

Yeah, absolutely. So for neonates, you consider it tachycardia if it's greater than 150 beats per minute. From ages 1 to 6, greater than 120 beats per minute. For ages 6 to 12, greater than 110 beats per minute. And then over 13, it's the same as an adult. Yeah, absolutely. So what about targets for fluid resuscitation?

Let's say you have a patient that comes in shock they're a pediatric patient. You're not going to bowl some 500 mls or a liter at a time. What are some numbers that we can go off of? Yeah. Where we use the, one of the test questions you're going to see, so you'll see it like how much our bolus number for crystallite, and that'll be 20 for blood.

It's 10 cc or milliliters a kilogram. And following the ATLS guidelines, they're gonna maybe ask, when do you give blood? I've seen test questions say you want to give it

after two fluid boluses and children. But I think it's so controversial now they're not going to ask that anymore. Your targets for suscitation is going to be your urine output is the best way.

And contrary to adults, you're going to, three milliliters per kilogram per hour in a neonate or infant and one milliliter per kilogram per hour in toddlers and a little bit older. Yeah, absolutely right. I wholeheartedly agree that it's now in the modern age with more balanced resuscitation strategies, you're probably not going to get a question that says.

Two boluses before you get to that first 10 cc per kilo of blood. But 10 cc per kilo is a good kind of metric to go off of Kevin, you want to tell the audience what do you expect the hematocrit to jump up by? If you give a 10 per kilo bolus of blood. Yeah. So rough rules of thumb for blood replacement is you have 10 cc's per kilogram of packed red blood cells will raise the hematocrit three to 4%.

And so one unit per 10 kilograms of platelets will raise the platelet count by

25, 000. And then 10 to 15 cc's per kilogram of FFP for the coagulopathy, and one unit per five kilograms of cryoprecipitate to replace the fibrinogen. Yeah, I think with pediatric patients, it's really good to know by weight.

And so the 10 cc's per kilo, a common rule for giving blood transfusions in pediatric patients, it's going to raise that hematocrit by roughly about three. All right, so let's jump into maintenance IV fluids. John, you want to tell us about the 4 2 1 rule? How are you going to calculate maintenance IV fluid rates for pediatric patients?

Yeah, so we have a nice chart in the chapter book as well, in the companion. But the 4 2 1 rule, so you want to give 4 an hour for the first 10 kilograms. Two cc's a kilogram an hour for the second 10 kilograms, and then one milliliter per kilogram an hour for the rest of the weight. So you can see the, you can see the chart in the book to help you with the calculations, but this is also a

commonly tested thing.

All right, Kevin, let's look at another common metric that comes up on exams. You're, resuscitating the patient, you're going through your ABCs, and on airway, how are you going to calculate the ET tube size in children? Yeah, so if you have a neonate, you only use uncuffed tubes, but as far as the size goes, generally it's the size of the pinky of the child is what you go with, or you can use the Broslo tape.

Great. I think that's a good rule of thumb, the size of the patient's own pinky, but a lot of times the test question won't you know, allow you to choose that. And they may have you calculate out what the size of the ET tube is. The Braslo tape is also a really good reference. You measure it against the size of the actual, the height of the actual infant.

Just to know for reference, the Braslo tape starts at roughly a three kilogram baby. And it's going to default to a 3. 5 uncuffed tube for that.

And so if you remember that and the other rule of thumb being the size of the ET tube is the age divided by four plus four. And then you take it down half the size for uncuffed tubes.

So that gets you to 3. 5. It's a, if it's a newborn baby Again, all these numbers are getting into the weeds. The way I remember it is if you're thinking about uncuffed tubes, the Braso tape defaults to 3. 5 uncuffed to start. Now, it is a little controversial whether you can or cannot use cuffed tubes in babies.

A lot of institutions in the modern era do use cuff tubes for babies. The only thing you need to know the whole like strategy of test taking here is cuff tubes can potentially if it's a size related issue can potentially cause a little bit more stress on the subglottic space. And we all know that the subglottic space is prone to develop subglottic stenosis in babies.

Okay, so let's go on to another commonly tested topic broad

differential here but let's tackle emesis. Emesis in neonates, infants and toddlers, adolescents, we're going to go through the range. John, we know that one of the most common differentiators you want to ask about up front is whether it's bilious or non bilious but looking at it by age, if you're thinking about neonates, what are some of the differential items that you're thinking about for emesis?

Yeah, these should be your go to thoughts when you see, emesis and you see the age on a test. So for neonates, for non surgical issues, you can consider infectious, allergic, or metabolic disorder. For surgical, it may be malrotation with midgut volvulus, GERD, intestinal atresia.

So common things being common, there are a lot of non surgical things, babies spit up for all sorts of reasons. And the key discriminator here is you really want, you have an onus to figure out which of these things are surgical and demand immediate

attention. And getting at that malarotation with mid butt ovulus being one of the most common tested surgical reasons.

And we all know that this is bilious emesis. Got to make you think about malrotation with midgut volvulus. Other forms of emesis just spitting up with a baby. It could be reflux That could be just you know baby with normal reflux Intestinal atresias are going to present in different ways But depending on if it's a complete atresia or like an incomplete web you can have varying degrees Complete atresia will definitely lead to emesis and then pyloric stenosis may be debatable if you're going to see that as much in the neonatal population, but once you get closer to three, four or five weeks old, that could be a common presentation as well, being non bilious emesis in pyloric stenosis Kevin, you want to take us into the infant and toddler range?

Yeah, so for the infants and non toddlers, as far as the non surgical ones, you want to think again,

infectious. Now you can start thinking about neurologic and psychologic causes of emesis, and then gastroparesis becomes an issue in this patient population. And then as far as surgical, I always think of the two year olds with the intussusception.

And so intussusception is one of them. And then once again, though, GERD can be present in this population. Yeah, absolutely. And, let's take it a little bit older, getting slightly older, maybe not all the way to adolescence, but getting into the older childhood range. What's one common condition now that we're thinking about for a surgical cause of emesis, John?

Yeah, looking at appendicitis for this patient population. Absolutely. And then you want to round us out with some non surgical ideologies of emesis in adolescents? Yeah, they're non specific, but a functional disorder, IBD and also a psychologic could also be causes. All right, good. Okay, let's rewind for a sec and go back

to a commonly tested scenario for neonates. So Kevin, let's say you had a premature infant who started feeds and then developed bloody stools after the feeding began.

That scenario makes you think about necrotizing enterocolitis. That all resolves. It was non operatively managed. And then several weeks down the line, they're starting to have emesis and feeding difficulty. What does that make you think of as far as diagnosis goes? Yeah, that definitely makes me concerned for some type of stricture.

Absolutely. Yeah. So we know that necrotizing enterocolitis commonly results in strictures post management. I would say the most common location for a stricture for neck is the colon but it can also happen in the small intestine. All right. John, you want us to take us into scenarios for non bilious emesis?

I know that pyloric stenosis comes up time and time again you want to take us through some common scenarios related to pyloric stenosis?

Yeah the buzzwords you're going to look at in the question stem for this are going to be projectile vomiting and then all of size mass in the upper abdomen.

thEy might have a patient that also has a metabolic disturbance. They're in just a reminder, but this is a hypochloremic hypokalemic metabolic alkalosis with paradoxical aciduria. Same type of scenario you would have with any patient has chronic vomiting or acute vomiting. The diagnosis for this is an ultrasound of the abdomen specifically look at the pylorus and it would be greater than four millimeters thick and over 14 millimeters long.

Yeah, absolutely. So very classic ab site test question, pyloric stenosis. So commonly tested that you really wanna memorize this metabolic disturbance, the hypochloremic hypokalemic metabolic alkalosis with paradoxic acid uea. As John said, the diagnosis, think about the word PI, as in

3.14.

Ps. Thicker than three millimeters in muscle thickness and longer than 14 millimeters in length that helps clinch the diagnosis. The diagnosis is made by ultrasound and it's a dynamic test. You're able to watch the infant swallow and see if any of the secretions or any of the milk makes it through the pyloric channel.

And so no passage through the pyloric channel is a good indicator that this baby has pyloric stenosis. So let's say Kevin, you've diagnosed pyloric stenosis. You take care of the medical emergency, which is the resuscitation. What fluids are you going to resuscitate with? Yeah, so generally you start with normal saline and then you go to dextrose containing fluids for your maintenance IV fluids before you go to the operating room.

Absolutely. So I think normal saline is a great answer choice if you're given this test scenario on the ab site because it's not going to introduce

any potassium before you know that the baby is making good urine. And you definitely don't want to be bolusing. large amounts of dextrose containing fluids up front because that can cause a significant osmotic shifts in a baby.

So normal saline is a great choice. Once the baby is peeing, then you can start to introduce some potassium. Okay, so let's say you're in the OR now, John, for this baby with pyloric stenosis, who's very well resuscitated. You go for your pylori myotomy. We've seen this question come up before. What are some independent markers Or signs in the operating room that you've had an adequate pylori myotomy.

Oh yeah, so you'd be looking for independent motion of the upper and lower leaflets when you did your division. And that they freely move and you can see the mucosal underneath. Great. So you want to make sure you have a good myotomy that goes all the way down.

You want to see the bulging of the mucosa. And as

John expertly stated, you really want to see that you have independent motion of the upper and lower myotomy edges. Is this like your favorite operation? This has to be so fun. This is a great operation as a surgical fix. And Kevin, to this point. How quickly can these babies go home?

You're, this baby comes in with an acute problem, you fix it. Are they ready to go home the next day? Maybe. Yeah. So in the common era, we have expedited pathways. And you may, this may come up, it actually comes up on pediatric surgical boards. You institute a a feeding program where you just feed them right away, maybe with some sugar water.

An ounce at a time escalate to two ounces of milk, and then they're ready for discharge. You counsel families that they will spit up to expect that but generally it's not gonna be that forceful kind of vomiting that they had before. Related to that. When you're making your myotomy,

which side of the myotomy is more likely if you do an incomplete myotomy to lead to an inadequate pylori myotomy gastric side or duodenal side?

I'm going to go with gastric side. So the most common complication. For the myotomy on the gastric side is an incomplete myotomy, leading to need for, a redo myotomy. What about on the duodenal side? Let's say you got carried away and took that a little bit too far, Kevin. What complication can you see there?

Yeah, it's not as robust there, so you can certainly have a perforation. Yeah. And, at least in pediatric surgical boards, if it's a small myotomy that causes a tiny duodenal perforation, you may be willing to over so that I would recommend that for the safety of your board examination it may be better to say the traditional old school teaching, which was you open.

or whatever it takes to get a good exposure, close the myotomy, and

then do a myotomy on either the contralateral or anti parallel side. Okay, so let's move on to another topic, very commonly tested tracheoesophageal fistula. In the question stem, most commonly you'll see a baby who may or may not have had polyhydramnios in utero and they're born and they are having trouble.

with handling of their secretions. Maybe they're coughing, maybe they're spitting up, maybe they're drooling. So some combination of that should clue you in on this. John, you want to take us through the types, the classification for TE fistulas? Yeah. So there's five different types and we'll go into the most common types afterwards.

But type A is isolated esophageal atresia. Type B is esophageal atresia with a proximal fistula. Type C is an esophageal atresia with a distal fistula. Type D is an

esophageal atresia with a double fistula, distal. And type E is an isolated fistula only, also known as the H type. And there's a very nice drawing within the companion to refer to.

Absolutely. Yeah, I would definitely refer to a photo here. I had the hardest time memorizing this. There are a number of mnemonics and tricks and tools out there. But honestly, I think if you go back to the principles of how this scheme was made in the first place Dr. Gross was a surgeon and this was a surgically devised classification scheme.

So if you were to classify this surgically, first, you'd have your normal anatomy, and then you'd have just the esophageal atresia. So that's your type A. Then you would have. The connection, the TE Fischler be proximal, and so that's your type B.

Next, you would have a distal TE Fischler, that's your type C. Then you do a double, which is your type D. And then your type E is your isolated

TE Fischler. Okay. Okay. A little bit about TE Fischler related questions that can test takers or test makers are more likely to... Ask on the boards here specifically related to EATFs, what are some associated syndromes or the other anomalies that you should be looking for as you work up this patient before you take them to the operating room?

Yeah. So I think the vectoral is the common syndromes that you look for. So you first look for vertebral anomalies by doing a sacral ultrasound. Then you look for anorectal abnormalities such as imperfect anus. And you do that with a rectal exam. And you look for cardiac with an echo and you obviously T.

E. fistulas is the T. And then renal use renal ultrasound and then limb anomalies. Absolutely, Kevin. I'd say if one of these was critical to have before you go to the operating room, it's going to be that cardiac echo. John, is there any particular vascular anomaly or

abnormality that you think is relevant to know before you take the patient to the operating room related to this echo?

I used to know this. I forget now. You have to remind me. So it's the aortic arch, the side of the aortic arch, and the reason it's relevant is typically these operations are done through a right sided thoracotomy. Whether it's transplural or extraplural, you're going to see both of those options.

VATS is even an option these days, but most commonly pediatric surgeons will approach this from the right side. And so if you have a right sided aortic arch, it's nice to know before you go into the operating room. Okay, we never actually talked about the most common types of tracheoesophageal fistula.

Which ones are the most common? Yeah, so I'd say the most common by far is going to be your type C. So that's going to be your proximal esophageal atresia with your distal TE fistula. When you see these patients come up on the exam scenario, you

may be given a chest x ray or a baby gram that includes chest and abdomen.

Kevin, you want to take a shot at this? Which of these anatomies is going to show you gas in the abdomen? Yeah. You're going to get that with your type H's and potentially your type D's and C's. Exactly. So any of the ones that has that distal fistula, where there's going to be that connection from the airway to the esophagus into the stomach, that's going to give you your gas in the abdomen.

By contrast, you have your, pure esophageal atresia, the type A's. Those, you might just get an x ray with a repulgal tube, the, basically the oroenteric or nasoenteric tube that's coiled up by the upper esophagus in a blind pouch, and then you'll see no gas in the abdomen. That clues you in that may be a type A or possibly even a type B, but more likely type A

esophageal atresia.

Okay. The reason that's relevant, I'd say clinically to know as a pediatric surgeon, you, the first discriminator is whether you see gas in the abdomen or not. The reason that's relevant is because if you have gas in the abdomen, the presence of the TE fistula makes it prone for the patient to have ongoing soilage of the lungs and reflux being acid exposure to the lungs.

If these babies end up needing to be intubated, that can cause a problem if the positive pressure ventilation selectively goes into that stomach preferentially, and then the baby has abdominal competition and has difficulty with ventilation. So there are scenarios where the baby can decompensate and those scenarios are more likely with the gas in the abdomen, the type C, the most common EAT fistula.

Okay, so that rounds out EATF. So let's now tackle a different topic, Kevin, let's go to the abdomen. So do you want to tell us a little bit about

inisception? How does that present? What are some buzzwords that you're looking for?

Yeah. And so this is the. The non infants that you think about the buzzwords or the current jelly stools or the target sign on imaging and they can potentially have bilious emissives if it's causing obstruction. And and it's also need to be more worried about this because you're concerned about a malignant lead point but in kids due to their hires patches and different things, they have a lot higher.

This is more common. And so that's for the ideologies and children. You'd think of the inflamed pyre patches with all the viral illnesses the kids have. And then you want to think about lymphoma and then Meckle's diverticulum as the ideologies for this. Yeah, that's perfect. So diagnosis is going to be made with that ultrasound looking for the target sign.

This is just a picture that you want to have imprinted in your mind. Very commonly shows up on the exam. If you see it. The next step is in the evaluation of the child is going to be to make sure they don't have any signs of peritonitis. So make sure your

question stem doesn't mention any of that.

And as long as they're stable, John, you're going to take them for what therapeutic maneuver. Yeah. So you want to look for air contrast enema on the question. Yeah, absolutely. This works so effectively that if this scenario has a patient. Have a recurrent interception following initial reduction.

That was successful. What's the answer choice next? Kevin air contrast enema. Yeah, exactly. So even if it recurs it could recur 15, 20 percent of the time. Even in that same ED stay, you're going to go for another repeat air contrast enema. So then John, when would you consider operating? Obviously if they have any concern for peritonitis, that would be your first step before any air contrast enema.

But if they failed the air contrast enema that would be one reason to do it. And obviously if there's a concern for perforation. Okay good. And two follow

on questions we've seen come up with in this section before. Kevin, let's say you have this patient in the ED, they undergo successful reduction, do you need to admit them to the hospital?

I have to admit, I'll be guessing, but I would like to admit them for overnight. Yeah, so I think traditionally the answer was, the safest answer was admit the patient, but more and more we know that with successful air contrast enema reduction. If the patient passes a P. O. challenge, the likelihood of an issue is exceedingly rare.

And so in the modern era, we typically discharge from the E. D. following a brief period of observation. And we have seen that come up on the exam. Let's say also related to interception, commonly tested. Where, which location is the most common location for an inisusception in a child?

I'm going to go with the ileocecal valve. Ileocolic

inisusception. That's by and far the most common. If you were to have a small bowel to small bowel inisusception, a lot of times you'll see that caught incidentally on a CT scan or imaging done for another reason. Most of the time those are inconsequential.

Okay, so moving on to the next topic, we talked a little bit about how inisception can potentially lead to bilious emesis, although, that's strictly because it's typically beyond the ampullae of otter, it's a distal process. But when you see the keyword bilious emesis, what does that really make you worry about, Kevin?

Yeah, and so when you're talking about an infant Billy's thing in a malrotation. Yeah. So specifically, the entity that we want to rule out is malrotation with midgut fulvulus. We all know that in embryology, the bowel starts out outside of the abdominal cavity, it makes a turn, and then it comes

back in and fixates against the abdominal wall.

And if that paternalization and fixation doesn't occur properly, then that can make the the baby prone to have midgut volvulus. John, you want to tell us a little bit about what LADS bands are? Yeah, LADS bands were formed from that embryology as well and they're adhesions to the right retroperitoneum.

So this bit is a little bit nuanced, but I think it helps conceptualize what is going on. Kevin, is it, what specifically in mal rotation is the main problem that is that, that needs to be addressed? Do you think it's the lats bands, or do you think it's related to the mesentery? Yeah, if I remember right, it has something to do with the mesentery being very, the base of it being very narrow.

Yeah, absolutely. You may see variations of malrotation or intestinal rotational anomalies,

and some of them have broad mesenteries, and those tend not to twist. It's really the ones with the narrow mesentery that are the problem. And so the primary goal of the operation, the LAD procedure, is when you go in, you're gonna make sure that the mesentery is nice and broad.

And as you're looking at everything, you're gonna take down any lads, bands that are right of the duodenum. I think I got ahead of myself and jump to the operative management. John, let's say you're seeing this baby in the ed. They don't look terribly sick. They look stable. What exam or next step are you gonna choose?

in the evaluation to diagnosis. Yeah, like you said, if they're not sick and they don't have an acute abdomen you want to attain an like an emergent or urgent upper GI to rule out malrotation as it is the most common cause of pediatric bilious emesis is always the first place you want to start.

Absolutely. So upper GI series is

definitely the answer. You should know what you're looking for in the upper GI is that so once the contrast goes into the stomach. It makes a C sweep of the duodenum. The contrast then comes back up to the level of the pylorus, to the right side, or sorry, the patient's left of the spine.

And on a lateral view it is, there's no gap between the contrast and the spine itself. So basically it makes it all the way to the retroperitoneal attachment, which is the ligament of trites. So if you see all those things, and then the contrast goes beyond that into the small bowel freely, then you have a good contrast study that rules out at least malrotation with midgut ovulus.

Okay, if there's ever a question is there any harm to taking this patient to the operating room? I'd probably say no. Everything comes with risk, but this is one of those diagnoses where if the patient is sick

and, upper GI is an answer choice, but you really are worried about this baby potentially having a midgut volvulus taking to the operating room before a certain diagnosis is not a bad answer choice.

All right. Kevin, you want to talk about any other associated conditions that may you may see in the exam as being associated with malrotation? Yeah. So you have your congenital diaphragmatic hernia seen in 20 percent of these cases, and then you have your omphalocele and gastrocesis.

Absolutely. I think, it's worth knowing that. Gastroschisis, typically by nature, is going to be mal rotated or have issues with rotation. Typically, these patients, because once all the bowel goes back into their abdomen and it scars in place, they're not the types of patients that are at risk of developing the same degree of mid gut volvulus.

They almost get like that. Adhesion

formation that you intend to create with the lab procedure. So john, you want to take us through in a little bit more detail what the lab procedure entails. Yeah, like you, you previously mentioned. So you're going to do taking the operating room up in the abdomen.

You're going to resect the last bands and then perform a counterclockwise to torsion to place the small intestine on the rights. And the large intestine on the left, and then we always do an appendectomy just mainly to avoid any future diagnostic uncertainty. Yeah, absolutely. I think that's the traditional way the LAD procedure was taught.

The question about appendectomy being mandatory in the modern area with CT scans. I don't think your exam is going to go into the weeds of that. But traditionally, absolutely. You're going to open that abdomen, inspect the bowel. You're going to detourse everything. Again, make sure you're communicating with anesthesia as you do the detorsion.

You're going to inspect the mesentery,

make sure it's nice and broad. You're going to take down the lats bands and in doing so, you essentially cocorize the duodenum and you want to make sure the course of that duodenum is nice and straight, going all the way down into the small bowel, which is on the right.

And then the large vowel, which is on the left. oKay. Before we move on from bilious emesis, another entity that you may see Kevin, you want to take us through duodenal atresia, what are you going to see on the question stem there? Yeah, super high yield topic. So you're gonna, you're the buzzwords are the double bubble sign on x ray.

This is the number one cause of duodenal obstruction and neonates. And so you're again, you're going to potentially see the polyhydramnios because they're not able to swallow. And then, of course, you have the cardiac, renal and G. I. Anomalies and down syndrome in 20 percent of these patients.

Great. That double bubble is so classic. Just make sure you look at an image and imprint that in your mind.

Other things that can cause double bubbles annular pancreas can do it. Even a duodenal web can do it. So just know that these other things are there, but if you see it on the exam, you just got to worry about that duodenal atresia.

It's going to be a scenario where the baby has never been able to feed well because An atresia by definition is a complete break, so nothing is getting beyond it. If anything has gotten beyond it, you get that x ray and gas distally, it makes you wonder, is it something incomplete like a duodenal web or an annular pancreas?

Okay? Let's say you have this duodenal atresia. You have the patient who also has down syndrome, trisomy 21 John what is that the first test you're going to want before you take this patient to the operating room? Yeah. So like we talked about previously, you're going to want a cardiac echo.

Absolutely. So specifically do we need an atresia unlike any other atresia? is something that you absolutely need that echo

before you go into the OR. A lot of times they can have crazy things going on with cardiac pathophysiology. They can have, complete AV canals. They can have all sorts of defects and it ties together very neatly as far as associations go with Down syndrome.

Okay. So If we talked about duodenal atresia being this complete break here, if we look at other parts of the intestine what is one thing that's different about, jejunal or ileal atresias, Kevin, as far as their etiologies go, do they form because of the same way that duodenal atresias form?

Yeah, no, so other intestinal atresias are due to intrauterine vascular accidents, most commonly in the jejunum, and can be multiple, whereas duodenal atresia is caused by failure of recanalization. Perfect. Okay, let's jump a little bit further along the intestine here, moving into a commonly tested phrase that you may see.

This baby was born. They had no prenatal diagnosis, but now it's been 24, 48 hours. And they still haven't passed meconium. John, what does this make you worry about? Yeah, hopefully they give you the meconium in the question stem, but I would be concerned about meconium alias in this patient. Exactly. So they may not say the word meconium, but they may say this baby is distended or maybe not.

And they haven't passed any stool. You examine their their bottom and you confirm that there's no anorectal malformation. So it makes you wonder, is this meconium alias? Okay. So there is an association with cystic fibrosis. You should know about that and that may clue you in on what can be a potentially diagnostic and therapeutic maneuver.

Kevin, what would that be? Yes. That's your gastrographin enema or your in acetylcysteine enema. Most commonly these days we're erring on the side of gastrographin enemas. Again, both therapeutic and

diagnostic. But the NAC is another consideration. So let's say you do this. You do this for a couple iterations in a row.

The patient is still having difficulty. You get another contrast enema, and this time you see an inverse rectosigmoid ratio.

So in that situation, I'd be concerned about Hirschsprung's disease. Yeah. The question stem may not play exactly out like this. But you have to worry about Hirschsprung's disease. If you have a contrast enema that shows that there. rectum is smaller than the sigmoid. So typically when you see a normal contrast enema, the rectum is more capacious, sigmoid looks smaller, but if you have a functional obstruction going on, it's going to reverse.

So your rectum is going to look smaller and your sigmoid is going to look bigger, proximal to it. If you see that pattern on a contrast enema, It's got to make you worry about

Hirschsprung. Hirschsprung is a very common cause of colonic obstruction in infants. It can also be delayed in diagnosis. So you may have a chronic constipation patient come in and it's just got to be on your differential that this may be something that's worth working up.

There are two scenarios related to that you can see. One is like a fairly stable, not sick child, but is having ongoing issues. And then there's the really sick child that's coming in with lethargy and fevers and looking septic. So let's talk about the first iteration where the, you're worried about Hirschsprung's being on the differential, patient's not too sick.

John, what are some first steps that you're going to take to help manage and diagnose this patient? Yeah, so you want to do rectal biopsies and these are typically done under like a suction rectal biopsy. And that will show absent ganglion cells in the myenteric plexus. And that's going back to embryology again, like a lot of things in pediatrics is due to forget failure of these to progress in the

CAUDAD direction.

Perfect. And Kevin, let's say It's the second scenario where the patient is septic. You got an x ray and it shows diffuse bowel dilation and the baby looks ill. What are the moves that you're going to do initially to help, manage and resuscitate this child? Yeah, so if they're septic and they're sick, I'm going to start with IV antibiotics rectal irrigations and then consider an emergent colectomy. Yeah, you know you may not need to jump straight to that collect me I totally agree, but you're absolutely right so the mainstay of therapy for Hirschsprung's associated enterocolitis And this is still in today's day and age a life threatening Entity patients still in the, late 2000s, 2020 patients have died from this.

So you really want to get ahead of it with rectal irrigations using saline and IV antibiotics and really make sure that they're well resuscitated. Okay, so let's move on to another scenario. John,

so we talked a little bit about inisception being a cause of bloody stools. There are some other etiologies in the pediatric population that are different.

than adults. When you see the word bloody stools in the question stem, what's another ideology that you should worry about if it's a premature infant? Yeah, I'd be thinking of necrotizing enterocolitis in this kid. Good. sPecifically it happens after the first feed. You're going to have a preemie after the first feed develops abdominal distension and signs of sepsis.

Kevin, you want to talk about features on that x ray? What will the x ray show you? Yeah. So the classic thing you're looking for is the pneumatosis. This alone is not an indication for surgery, but also you're looking for free air and then some. Poor prognostic signs are things such as portal venous gas, and many times you're going to do serial lateral decubitus films to monitor perforation.

Good, good.

The lateral films are specifically helpful for the perforation and the free air. Okay when you get labs on these patients, John, is there one particular lab value that stands out specifically in the pediatric and neonatal population? If you see maybe that this number is very low, it's got to make you worry that the patient is getting sicker.

Yeah, so thrombocytopenia is a good indication things are going poorly. Absolutely. A little bit different than adults. You really got to look out for that thrombocytopenia in the neonates. Okay. We've started treating this baby, let's say with resuscitation, NPO status, broad spectrum antibiotics.

You're going to do a nasogastric or gastric decompression. Kevin, what are the indications to operate? Do you operate on all babies that develop pneumatosis? No. So the only absolute indication is if they have pneumoperitoneum. But then of course, if they develop peritonitis or they have clinical deterioration, you'd want to operate on these patients.

Yeah, and this is

getting a little bit deeper into the weeds, but does occasionally show up. Is there a size of a baby at which you may worry that the risk of laparotomy may be a little bit greater and so you might consider doing a drain placement? So yeah, in neonates that are less than one kilogram you have to be concerned about. The harm of a laparotomy, right? Absolutely. So I think just, generally speaking, it's a good cutoff to be aware of that if they're very small, less than one kilogram you may consider placing a drain primarily the nuances of that are a little bit in the weeds, but I think for the app site, that's a good number to remember.

Okay. So another common board scenario that you'll see John, you have a two year old that comes in with. painless GI bleeding. What does that make you worry about? Yeah, I'd be worried about Meckle's diverticulum and that's a small bowel diverticulum due to a persistent

amphalomezenteric duct.

Good good. Most commonly, as we said before, painless lower GI bleeding. And these toddlers can come in with very low hemoglobin levels. And Make sure you're resuscitating them as you work them up. Kevin classically we talk about the rule of twos, you want to walk us through those?

Yeah, so generally it'll be about two inches long, it'll be two centimeters in diameter, they'll be less than two years old, there's a two to one male to female predominance, it'll be within two feet from the ileocecal valve it's in two percent of the population but only 2 percent are symptomatic. And there can be two types of tissue within it, both pancreatic and gastric.

Very good. So related to that ectopic tissue here John, what is the mainstay of diagnosing Meckle's diverticulum? Yeah, you talk about Meckle scan is a good, is the mainstay for diagnosis, but it only pick up if the diverticulum has gastric mucosa within.

I think knowing that physiology is helpful.

Every once in a while there are questions about what can be used to enhance the sensitivity of this scan. And once you remember the gastric mucosa, it may help you remember H2 blockers can be used to increase the sensitivity. H2 blockers specifically and glucagon can as well. Okay. So Kevin, let's say you've diagnosed a Meckles.

You're going to take this patient to the operating room after they're resuscitated. You go in there and that it's a narrow based Meckles diverticulum. There's no ulceration on the, on the anti mesenteric side. What's going to be your operation? Yeah, so if it's just the Meckles without any other issues, I'll do a resection of the diverticulum.

If it's more than that, I would consider a segmental resection if it involves the base. Yeah, very good. I think that's a great way of thinking about it. So diverticulectomy is still an appropriate operation, but if there's

anything on the stem that makes you worry about the integrity of the bowel on the opposite side of it, then you can do a limited small bowel resection.

Okay, John, let's jump into some abdominal wall defects. Do you want to take us through some of the differences of a gastroschisis versus an emphylocele? Yeah, sure. Yeah, like you mentioned, the two you want to think about are gastroschisis and emphylocele. So the etiologies is walking down through these, and it's once again, nice chart in our companion for gastroschisis, the etiology is not well understood may do be due to a failure development of the ventral body wall during embryogenesis and for emphylocele.

It's due to failure and embryonic development. gAstroschisis will not have an overlying or overlying sac. Amphalocele will have a sac and it may contain other organs. Gastroschisis is located to the right of the midline and amphalocele is in the Direct midline.

Gastroschisis has some associations to include intestinal atresia, which is the most common, and malrotation.

anD emphylocele is associated with Beckwith Wiedemann syndrome and trisomies 13, 18, and 21. The diagnosis for gastroschisis and emphylocele are the same with an obstetric ultrasound. You usually see these in the prenatal period. The treatment for gastroschisis initially is to wrap whatever is exterior to the abdomen with a moist wrap, resuscitate the patient, start them on TPN, and keep them in PO.

Once you're ready for definitive closure, you can replace the bowel and then perform a primary closure. Or do a scholastic mesh silo to walk things back into the abdomen. For emale, it's about the same but you may need a patch if it's giant and there's a large defect present. And finally the prognosis. Is better for gastroschisis is better than in fallacy. Absolutely. So thanks for taking us through that. I think it's. Really

nice to look at this chart. About the key differences there can be varying degrees of presentation. You can have, small defects, you can have large defects, you can have giant and fallacies that contain liver.

So the spectrum is far and wide. I don't expect you to be tested on the weeds of this in the exam. But I think this chart gives you a broad overview of the most common scenarios that you may see come up related to gastroschisis and emphyseal. Okay. Related to the midline umbilical defects.

Let's talk about umbilical hernias. Kevin in a pediatric umbilical hernia, when are you going to recommend repair? Yeah, this always drives me crazy having kids come in with pretty big hernias and we have to say wait till they're in kindergarten. So generally when they're five years old is when you consider closing these hernias.

tHere are a number of factors that maybe predispose this umbilical hernia to be less likely to close or more likely to close. Sometimes you

see risk factors like a proboscoid umbilical hernia where the skin. Is Purdue protuberant like an elephant trunk by and large, you're going to recommend repair if it still hasn't closed by about kindergarten age.

Okay, what about inguinal hernias? John, the ideology we know about the persistent processes vaginalis. What's different about treating inguinal hernias in kids compared to adults?

The treatment for kids in comparison adult is elective high ligation of the sack. Sometimes I've seen scenarios come up on the ab sites is where you have a kid with an incarcerated hernia come in and you reduce it in the E. R. And what do you do next? Typically you want to get these patients to the or within 72 hours.

Yeah, I think that's a great safe way to think about it. So high ligation of the sac is going to take care of that patent processes vaginalis. Unlike in adult hernia repair, typically you're not

going to need any sort of mesh repair with these kids because they're by definition. pure indirect inguinal hernias.

Now the scenario that John mentioned is very commonly tested, the incarcerated inguinal hernia. So typically if it's reducible If it was a very challenging reduction, and you were worried that the bowel could be threatened at any stage of it, it's better to make sure that inguinal hernia is repaired before that patient discharges.

If it was, a fairly reducible hernia, you do have time on your hands and you can, extend that period of time. You're not obligated to 72 hours, but I would read into the question a little bit to I'll let it guide you as far as how much leeway you have as far as the repair goes.

There is a, another commonly tested scenario regarding incarcerations. That's a little bit different. Kevin, what about when you see a baby that comes in, it's a girl and they had

ovary in the inguinal hernia that was seen on ultrasound. You evaluate it and you're able to reduce it. Is there anything different about the ovary that changes your management? Yeah, so in a female with ovarian in the inguinal canal, you should fix it within two weeks. Yeah, I think that's a really safe way to approach it.

Make sure it's reducible. Parents don't need to obsess about reducing it all the time, but within a reasonable time frame, like two weeks, you want to try to get these repaired. Okay. One thing that you should just be aware of is. If you have a female with an inguinal hernia, so a baby girl with an inguinal hernia it may be a reason to evaluate the gonadal structures because there is a rare scenario where you have androgen insensitivity syndrome.

And so if you have a female with an inguinal hernia, that can be an association. So if you have a

female inguinal hernia, just in the back of your mind, know that this one obscure Disorder of sexual differentiation, DSD, called Androgen Incentivity Syndrome, does exist. Okay, Kevin, let's talk about hydroseals.

So how are hydroseals classified? Yeah, so you have your communicating and you have your non communicating. So the non communicating usually resolved by one year, whereas the communicating can wax and wane. And these are similar to a hernia, but the sac does not extend into the internal ring. Very good.

Okay. Anything about surgery for hydroseals that you think we should know? Yeah, so surgery at one years old, if they have not resolved or if it's communicating in, in that situation, you resect the hydroseal and ligate the process vaginalis. Okay, good. So same sort of operation actually. All right. What about

cryptorchidism?

So let's say you have undescended testicles. What association should we be aware of? Yes, you have to be worried about the risk of testicular cancer even after they've had an orchiopexy, particularly a seminoma and a chromosomal disorder if undescended bilaterally. Okay. Let's dive into abdominal masses. Very commonly tested. A lot of times the presentation is going to be a two or a three year old who is taking for a bath and grandma notices that there's a an abdominal mass baby is asymptomatic. KeVin, as you get the history on this. Child, what are some of the other features that you're going to ask about?

Yeah, I hate talking about these things with the young kids at home. Definitely makes you nervous, but so you want to know if they have any history of hypertension, diarrhea, or raccoon eyes from,

potentially orbital metastasis, or if they have an unsteady gait. And, John if we hear about any of these features, what type of abdominal mass are we getting more and more worried about?

Yeah, I'd be concerned about a neuroblastoma.

Yeah. So I think you guys are absolutely right. The unsteady gate in particular is referring to obstaclonous myoclonus ataxia syndrome very classically associated with a neuroblastoma. Kevin, you want to tell us about some other features related to neuroblastomas? Yeah, so these generally originate from the adrenals, but can be anywhere along the sympathetic chain.

These patients will be generally young, less than two years old, and the best prognosis in these patients, if it's caught early, less than one years old, and they rarely metastasize. And To diagnoses, you're going to get catecholamines, metanephrines, VMA, HVA, and an abdominal x ray looking for stipulated

calcifications.

And then you're going to look for a CT scan showing renal displacement. Whereas a Wilms, you'll actually see it replaces the parenchyma of the kidney. And I think that makes sense, right? Because all these associations with adrenal tumors or neural crest tumors The same sort of biomarkers are there.

It's typically arising near the adrenal gland. And if you have that, it's going to displace the kidney, as opposed to Wilms, which arises from the kidney itself. Okay, there are a couple markers in particular, John, that we might see in the question stem. What markers might you look for that tend to worse prognosis for neuroblastoma?

Yeah, the one I remember specifically coming up before is the neuron neuron specific anomalies. But I also want to look for LDH, HVA. The diploid tumor or MYCN amplification. Yeah, the MYCN or NMYC.

I've seen it written both ways, but the MYCN amplification that in particular is very commonly tested.

Okay. What about treatment, Kevin? Yeah, so resection and you can try neoadjuvant doxorubicin if it's unrespectable. Yeah, I think broadly speaking we shouldn't get too far in the weeds for a general surgical ab site. I think this is a good way to think about neuroblastoma. Okay John, how about for Wilm's tumor?

Yeah, these patients present, they're asymptomatic hematuria, they may have hypertension. 10 percent of Wilm's tumors are bilateral, and the average age for presentation is 3 years old. These metastasize to the bone and lung if that's the case, they may require radiation going forward. We can diagnose these with an abdominal CT, and like I mentioned before, you're going to see replacement of the renal parenchyma.

These are associated with the Wager

syndrome. Actually, I don't know if it's a syndrome specifically, but it's the Wager association. So W A G E R. So you have Wilms, aniridia. GU malformation and mental retardation. thE treatment for these is nephrectomy without rupturing. And that if it does rupture, that will upstage the tumor.

And you want to do post chemotherapy with actinomycin and vincristine. Great. I think for whelms, it's specifically important to know this association with upstaging by rupturing the tumor or violation of the tumor. And so this is a type of tumor where if you have a classic. Finding on CT scan, you would not proceed with biopsy.

So if you see biopsy like core needle biopsy as an answer choice and it's clearly Wilms tumor, that's the wrong answer because it obligates a higher type of treatment modality. And the patient may

otherwise have been amenable to a resection alone or resection with a minimized kind of protocol for chemotherapy.

And so it's very important to know that for Wilms. Additionally, for Wilms, more and more, this is coming up on exams, is the importance of lymph node sampling. So if there are two different answer choices, one of which that offers resection plus lymph node sampling, that is the answer that you're going to go for.

Okay. The other thing, John, you had mentioned that bilateral, 10 percent are bilateral. This is very unique to Wilms tumor. If you see a picture or an association on the exam with bilateral kidney tumors, the diagnosis there is Wilms tumor. All right, so that takes us to hepatobiliary.

Kevin, you want to talk about cold local cysts? How are they classified? Yeah, so you have five types. Most common is type one, the fusiform, and let's just talk about the rest of them

also. Once again, we have a nice image to help you visualize this. This actually is testable. Oh, boy. Wouldn't put this in here if it wasn't cause it's, not very common that we see in our own practices in general surgery.

But so one is the fusiform dilation of the biliary duct. Number two is the diverticulum, the solitary diverticulum. Number three is the choledococele, which means it's the dilation within the ampulla right at the duodenum. Type 4a is the intra and extra hepatic. Dilations. And then type 5 is the multiple intrahepatic, also known as Corolli's disease. Yeah, absolutely. So with all these, I think it's nice to know exactly where the location of the lesion is, because based on that, you're going to be able to determine what sorts of treatment modalities listed here on the companion are going to be most helpful.

Let's talk briefly about one pathophysiologic etiology of

choledoplosis. This does come up periodically on the exam. Thank you. So it's thought to be related to a anomalous or long pancreatic o biliary duct junction. And John, what in particular does that predispose the biliary tree to, if you have that long anomalous pancreatic o biliary duct junction?

Yeah. That can lead to reflux of pancreatic enzymes and utero and can lead to this. And the rationale behind treating cold local cysts is that it is thought to be or pretend a risk of future malignant transformation. Okay. So let's move on to another hepatobiliary condition. Kevin, you want to tell us about biliary atresia?

Yeah, this is a terrible condition where the biliary ducts never develop. So it's the most common indication for pediatric liver transplant. And generally these patients will present with neonatal jaundice. And the treatment of these is a liver biopsy that'll

show the periportal fibrosis, a bile plug and then you can use ultrasound and cholangiography also to make the diagnosis.

Yeah, I think that's a good way of thinking about it. I think slightly more nuanced is that more and more we're understanding that it may be a progressive inflammatory kind of progression that leads to these biliary ducts becoming obliterated. And as Kevin said, persistent neonatal jaundice.

If you see direct hyperbilirubinemia in your question stem, you got to worry about it because getting that diagnosis and treating biliary atresia before the age of three months, ideally even two months is going to be critically important for the success of the procedure to treat it. John, what is that procedure called?

Yeah. One of my favorite names to say, it's the CASI procedure, which is hepaticoportoidrogenostomy is the first step you want to do for

these. Yeah and we're taught the Kasai procedure has the rule of thirds, a third of patients improve right away, a third progress to transplant, and a third, die in short order.

I think, in the modern era the outcomes are actually a little bit better than this, it's not quite like this but I think one way you can think about it is that a third of them are going to clear their bilirubins and develop colored stools right away. And then a third are going to. Go on to clear initially, but then probably need a liver transplant in the, coming months to years and then, the last third of them As, as good as it can get, typically is in like the teenage to twenties year old range before they're going to need a liver transplant.

I don't think it's ever really the case that a Kasai procedure is going to take that patient to, lifelong success. But at least it's going to get them a lot of time before they go on for a transplant.

Okay. So Kevin, let's talk about thoracic. So what are the four types of?

Congenital lung lesions. Yeah, so you have your pulmonary sequestrations, you have your congenital cystic adenoid malformations, you have your congenital lobar emphysemas, and you have your bronchogen, and you have your bronchogenic cysts. So I specifically asked it this way because This is actually changing and it's still so confusing.

So we used to call many of these C CAMs, Congenital Cystic Adenoid Malformations. The language has changed a little bit to C PAM Congenital Pulmonary Airway Malformation. So you're gonna see C PAM probably on your exam. C PAMs and pulmonary sequestrations exist on a spectrum. The main differentiating factor is that the pulmonary sequestration is going to

have that feeding vessel, whereas the CPAM does not necessarily.

So let's talk a little bit more about pulmonary sequestration. John, can you help define this a little bit more for us? Yeah, so this is lung tissue that doesn't communicate with the tracheobonchial tree and it has independent blood supply from the aorta. tHe venous drainage can be systemic or extralobar or pulmonary intralobar.

The presentation. of pulmonary sequestration is infection or an abnormal chest x ray. The treatment is that you want to ligate the arterial supply, which once again it can be directly from the aorta and you want to perform a lobectomy. Perfect. So by contrast, Kevin, let's say you have, let's say it was a lower lobe, right lower lobe lesion.

And there's no feeding vessel. Make sure you think it's a CPAM. What's the treatment for that?

Yeah, in that situation, it's just lobectomy. Yeah, exactly, right? So it's nice to have a CTA. So a lot of times in the question stem, you'll be given an x ray with what looks like a lesion, typically in the lower lobes.

One of the right lower lobe and it's gonna ask what the next step is, CTA, figure out if there's a feeding vessel, and then you can go for lobectomy with or without ligation of the feeding vessel. Okay. By contrast, let's say you have a scenario where this is a baby or a young infant that comes in with respiratory distress, they get an x ray, and it looks like there is It's a lot of aeration, like overinflation almost of one side.

It's going to make it seem like the answer is a chest tube, or a chest tube is going to be one of the answer choices, but we know that's the wrong answer choice. Kevin, what's this scenario? Yes, this is your

congenital lobar emphysema. So it can be frightening because when you look at the x ray you want to look at it closely because it can confuse you into thinking this may be a tension pneumothorax presentation and this has led to enough confusion that in real EDs people have put in chest tubes and Basically led to dramatic air leaks because they've punctured overinflated emphysematous congenital lobar emphysema.

So by contrast, that is not what you want to do. You want to take the patient to the operating room and do a lobectomy. And this lung is really not functioning all that well. It's taking up space. You take that dysfunctional lobe out, let the remaining lobes expand and the patients generally tend to do better.

Okay. Moving on to the last category, John, a little bit of more detail about bronchogenic cysts. Yeah, so these are extra pulmonary cysts of bronchial

tissue and cartilage. The most common presentation for this would be a mediastinal cystic mass. And the treatment is resection. Okay, very good. Real briefly, we may not get a lot of questions on congenital diaphragmatic hernias, but we do occasionally see a little bit about the classification of these.

Kevin, can you tell us about the two different types of diaphragmatic hernias? So you have your Bach, Deek, and mor gagny. So the Bach Deek is the most common and it's found posteriorly. The Mor Gagny is rarer and

it's in the anterior portion of the chest. Perfect.

So for congenital diaphragmatic hernia most of these patients these days are being diagnosed prenatally. And so we have a lot of information going into the operation. We're not going to need to go deep into the weeds about that, but really just know that there's an association with pulmonary hypertension.

A lot of

times because of that, Thank you. These babies, as soon as they're delivered, may end up needing to go on ECMO. a Hundred percent of them are gonna go on mechanical ventilation initially to sort out what needs to happen, but ECMO may need to be a modality that's used to stabilize them.

Okay let's move on to the neck. Kevin, you want to tell us about the brachial cleft cysts? Take us through from the angle of the mandible all the way down. Yeah. So at the angle of the mandible, you have your first brachial cleft cyst. The second brachial cleft cyst is the upper mid neck anterior to the sternocleidomastoid right where the carotid body is.

And then your third and fourth brachial cleft cyst are in the lower neck anterior to the sternocleidomastoid. And then you expect to see your thyroglossal ductus in the midline. Good. Yeah, I think that's a really good way to think about it. Start at the angle and just march your way down one through four.

All right. John, how about for

a little bit more about thyroglossal duct cysts? What are the things that you should do when you're working up a patient with a thyroglossal duct cyst? Yeah, so just a reminder, we talked about it briefly. So these are midline cysts versus the brachial cleft cysts, which are lateral they will often go through the hyoid bone they're formed from an abnormal descent to the thyroid gland and may be the patient's only thyroid tissue.

So you want to make sure you do a thyroid ultrasound While working these things up perfect thyroid ultrasound. Okay. So Kevin, we've gotten that ultrasound. We're taking this patient to the operating room. Tell me about the procedure. Do you just take out the cyst? Do you have to take out anything else?

Yeah. So the procedure is typically called a cyst trunk procedure, and this is going to include the excision of the cyst itself, the tract and the hyoid bone to the base of the tongue. Very good. Yeah. Very important to take out that hyoid bone to reduce the risk of recurrence.

Okay.

Back in the day we used to see this term cystic hygroma come up a lot. It's still in a lot of test. Taking strategy sort of textbooks. So it's in ours as well, but it's worth noting that the terminology is changing here. So cystic hygromas nowadays you can think of it as lymphatic malformations.

Classically you see the picture of the child with the bi