[0:08]What's up, Ninja Nerds? In this video today, we're going to be talking about bowel obstruction. This is a part of our clinical medicine section. If you guys like it, it helps you, please support us and you can do that by hitting the like button, commenting down in the comment section and subscribing.
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[0:45]With mechanical bowel obstructions, there's literally something that's blocking the lumen, right? It's literally, it's just a big old barricade within the lumen that's preventing intraluminal contents, food, fluid, any kind of like intestinal contents.
[1:00]It's not being moved through the actual GIT, right? So this is the problem is that you're not having the proper movement of these contents.
[1:10]There's not really an issue with motility, so the actual smooth muscle here, this is actually intact.
[1:17]So motility is okay. The problem that is existing here is that you have a physical obstruction.
[1:23]So motility's fine, but there is actually some type of physical obstruction and that's really where the issue is, okay? So there's a physical obstruction, but there's no problem with motility.
[1:38]Motility is okay. So that's the big, big kind of things that I want you guys to understand with mechanical obstruction.
[1:45]Oftentimes if anything, the motility is actually increased because you have an obstruction here, you can't move things along. So what happens is the bowels are like, okay, I'll squeeze a lot harder to try to push this stuff along.
[1:54]And so that's usually what happens is motility actually increases in the early phases. Usually motility goes away in the late, late pages of uh, bowel obstruction at the point where they're actually out an ischemic bowel.
[2:05]But that's the big thing for mechanical obstructions. If we come over here now to functional obstructions, it's a little bit different.
[2:11]There's really no problem here where there's something in the actual lumen obstructing the intraluminal contents. So in this particular scenario, there really is no physical obstruction.
[2:24]That's not the issue whatsoever. So because there's no problem with a physical obstruction, what do you think is left?
[2:30]Motility. The motility is actually going to be the problem. So in these particular patients, they have no good GI motility.
[2:42]The muscle is actually going to be the issue here and if the muscle can't contract, it's supposed to induce what's called peristalsis.
[2:48]And so in this particular sense, this peristaltic wave that moves intraluminal contents down is not occurring.
[2:56]And so this is the same concept. You see how intraluminal contents are not moving, it's just in this, there's an obstruction, normal motility, here, no obstruction, and there's decreased motility.
[3:06]And we can actually use that here, there's decreased motility. So this is really kind of the big differences here and these different types of obstructions, right?
[3:19]Now, when you look at these also in another particular way, let's say I take a section because this is a section of the actual GIT, that's a section of the GIT.
[3:28]And I kind of make another little diagram. Another big thing here is that whenever you look at mechanical obstructions, they have this part here that's really kind of like crucial and helps you to identify the differences between them on radiographic images, is that right here.
[3:40]Let's say is the physical obstruction, so everything proximal to that is becoming distended. So all this is distended bowel.
[3:50]Everything up here, above the transition point. Everything below the transition point is decompressed.
[3:57]That's, I think, super, super helpful to think about when you're looking at these radiographically, right?
[4:03]Whereas here, do you notice any transition point? No. So there's no transition point. And I think that's what's super helpful.
[4:15]And this sense the bowel is actually distended throughout. So they have distended bowel loops throughout their small intestine or throughout their large intestine.
[4:24]And I think that's what's super helpful. Is that this is distended about only proximal to the obstruction, decompressed distal.
[4:30]This is distended throughout. So let's actually write that down, distended throughout.
[4:41]Okay. So I think we have somewhat of a decent idea here about some of the small differences between mechanical and functional obstruction, which is good because oftentimes they can present similarly.
[4:52]So often times these patients usually present with what's called Cavo findings. This is that classic finding that I want you guys to remember. And so what this means is is they often times will have cramping abdominal pain, abdominal distension, vomiting, and obstpation.
[5:10]That's really the big features that are super classic. So if a patient comes in, cramping abdominal pain, they have abdominal distension, vomiting, obstpation.
[5:19]Think, do they have a bowel obstruction? Is it mechanical, functional? Think about which one is blocking the contents, which one's a problem with motility.
[5:30]If it is, I know that radiographically, I'll be able to identify this based upon the pathophysiology.
[5:36]But then, once I've done that, and I say, hey, I found the actual obstruction, what's the cause?
[5:41]And more than that, where is the obstruction? Is it only affecting the small bowel or the large bowel? Let's talk about that now.
[5:49]So if we move on to the next part here, let's say that we're only focusing on mechanical obstructions that affect the small and large bowel.
[5:56]For the small bowel, the most common cause by far is going to be the surgical adhesions that stick between the bowel and obstruct it, right?
[6:05]So I want you to remember adhesions as a super, super common cause, by far, the most common. And I think one of the telltale signs that'll help you guys to remember this one is that it's often usually due to abdominal surgery.
[6:20]So look in the history for multiple abdominal surgeries in their history, because this is going to be some of that scar tissue that's remaining there.
[6:31]A second one is going to be hernias. So let's say here is the inguinal canal or the femoral canal, and a piece of bowel herniates out through that, that space or that canal.
[6:41]Now you're pinching on the bowel, creating a transition point, just like here, it's pinching on the bowel, creating a transition point. This is hernias.
[6:50]Hernias, I think the big ones to remember are going to be ones that can easily be incarcerated and unfortunately strangulated. And this is going to be, you want to watch out for femoral ones.
[7:00]These are the scary ones and inguinal ones. And often times they'll complain of pain in those particular areas, and when you go to examine them, you may find that visible palpable mass.
[7:13]The third and final one, I would say, is not as high yield, because it's not super common, but you want to think about it in the pediatric population.
[7:20]And this one I would say is going to be intussusception, right? And in this scenario, you want to think about this in like young children and it's usually going to happen near the iliocecal junction.
[7:34]They have this thing called a Meckel's diverticulum, Meckel's diverticulum, and it creates this kind of like little leading point that causes the ilium to kind of get sucked in and telescoped into kind of like the inner part of the cecum.
[7:46]So you see how this is the inner, like the proximal bowels right here. Imagine here, I have my left hand as the proximal bowel, here's the distal bowel, it gets sucked into the actual inner segment of the distal bowel and it creates a little transition point, therefore, obstruction.
[8:00]So this is going to be in young children and usually they'll have something called a Meckel's diverticulum that this will kind of cause this lead point to lead into this kind of telescoping usually at the iliocecal junction.
[8:14]All right. For the large bowel, what's causing the transition point, the mechanical obstruction? It's usually pretty straightforward, it's some type of like tumor.
[8:23]Usually, it's intraluminal in the scenario of, uh, usually this is a neoplasia, or neoplasm. Um, and this is usually in the setting of something like colorectal cancer.
[8:33]Could it also be extrinsic compression from some type of intra-abdominal tumor besides from the GIT? Sure. Could be, but I'd say colorectal cancer would probably be the more common one.
[8:45]And then the last one, really interesting one here, is going to be a twisting of the bowel. And this is called a volvulus.
[8:55]Now, volvulus is really interesting and it's usually concurring two forms, uh, concurring in children, uh, usually in the midgut region, but that's what affect the small bowel.
[9:07]Sigmoid colon is usually going to be the distal part of the large intestine, and so that'll affect the large bowel. So you're going to see this more in adults.
[9:14]So seniors who have chronic constipation, the poop builds up in that sigmoid colon, cause it to become distended, and it literally twists on itself, creates this two kind of lead points and twists on itself and create the transition points.
[9:30]So this would be something you look for in chronic constipation, especially in the elderly. All right. So with all of this being said, we now have at least a differential that we can form whenever we say, oh, this patient has a small bowel obstruction.
[9:47]What's the causes? They have a chronic or they have a large bowel obstruction, what's the causes? With that being said, let's now take the next step here.
[9:54]Patient comes in, they have Cavo findings, you think that they get an x-ray, and you see some potential findings that would suggest more of a non-mechanical obstruction related bowel obstruction, so it's more functional and physiological.
[10:10]So then you're thinking, okay, if it's affecting the small bowel, there's a special disease for this one. And you see how there's no transition point.
[10:19]It's literally the, the muscle of the bowel is paralyzed. And what we do here is we call this one, we call this a paralytic ileus.
[10:33]And a paralytic ileus is essentially when you have dilated loops of small bowel that are pretty consistently throughout the entire small bowel.
[10:46]Usually greater than like 3 centimeters. Usually that's kind of like our number that we'll say that it's greater than 3 centimeters for that dilation there. That would be suggestive of a paralytic ileus if there's no transition point with a decompressed distal bowel.
[11:00]So then you have to ask yourself the question, what the heck would cause my smooth muscle to become paralyzed and not contract? Well, there's a couple different things.
[11:10]And we use the P's mnemonic. We say it could be due to an infection of the peritoneum, like peritonitis, right?
[11:18]So, does if a patient have peritonitis, I still didn't spell it correctly. Here, let's fix this, peritonitis.
[11:36]Now, in this patient who has peritonitis, what happens is they get inflammation of the peritoneum. The peritoneum literally is going to cover the actual GI organs.
[11:43]And so if they get inflamed, sometimes it can actually cause that smooth muscle to not contract very well. So that could be one potential cause.
[11:51]Another one is it could be due to, are they having some type of post-abdominal surgery? You went around there, mucked around in the abdomen, those bowels are going to have a little bit of a tough time being able to get back to their normal contractile activity.
[12:03]So it could be postoperative. Sometimes this could be because of the surgery itself, or it could be because of the medications that were given. So some of the anesthetic medications, like the sedating medications, the paralytics, etcetera.
[12:17]It also could be because the potassium is low. The potassium is really important and it has a very significant effect on, you know, a lot of the contractile activity of the actual smooth muscle.
[12:28]And so if the potassium is early, they have what's called hypokalemia, that could also paralyze that smooth muscle temporarily. Lastly, and probably the most common one, I think chronically, is pain meds.
[12:39]And so patients who are taking opioids, whether this be in large doses acutely, or whether this be in large doses chronically. These medications definitely decrease the actual contractile activity of the smooth muscle.
[12:51]So if you think about these things, all they are going to do is, pretty straightforward, is they're going to act on the smooth muscle of the small bowel or the large bowel, and they are going to inhibit this actual muscle.
[13:03]And so you'll have a decrease in the motility, but you'll have no physical obstruction. If I have a decrease of motility, can I move things along the actual small bowel or the large bowel? No.
[13:16]And so you'll have distended bowels because they're going to stay in that area. Okay? Same thing exists in a patient who has dilated large bowel.
[13:28]All right. Usually, if it kind of dilates different parts here, so if you kind of dilate out the large bowel, like the the transverse colon or the ascending colon or the descending colon, then this is kind of different.
[13:43]So this is actually what we refer to as colonic pseudo-obstruction, colonic pseudo-obstruction. Sometimes they also give this the terminology Ogilvie's syndrome, okay? Ogilvie's syndrome.
[13:58]And basically what happens is that you have dilated loops of large bowel. Usually the telltale sign is that cecum is gargantous.
[14:09]Usually when the large bowel themselves are like greater than 6 centimeters. So if it's getting to the point where they these puppies like these parts are greater than 6 centimeters or the cecum is like greater than 9 centimeters, then man, this is getting pretty stinking bad and you want to watch out for that.
[14:28]So if the cecum is getting really big and the other parts of the large bowel getting really big, they're distended throughout, no decompressed distal bowel or transition point, it really suggests more about functional obstruction.
[14:40]Same thing though. Both of these in the small, large bowel, whether it's colonic pseudo-obstruction, paralytic ileus, are usually due to these particular causes, it's not a mechanical obstruction like in these scenarios here that we talked about.
[14:52]Now that we've talked about mechanical and functional bowel obstructions and how they'll present, let's now talk about the complications of these. All right guys, so now we're going to move on to the next part here, which is when a patient who has a bowel obstruction, they come in, right?
[15:04]They present with that cavo findings, the cramping abdominal pain, abdominal distension, vomiting, obstipation or constipation, right?
[15:13]You're like, okay, is this more of a mechanical? Is it a functional? Again, you'll base that on some of the radiographic findings in their clinical history.
[15:21]And then if you're thinking, ah, you know, if it is a small versus a large bowel, how do I really differentiate that? Again, more of a radiographic type of thing that you'll kind of base it on.
[15:31]Um, now, when a patient who also has, again, a mechanical or, I'd say, functional bowel obstruction, they are at risk for some potential complications.
[15:42]And some of these that you should be aware of are the following. So the first one is hypovolemia. These patients can become could like pretty significantly volume depleted and it's kind of a multifactorial mechanism behind it.
[15:54]So pretty straightforward though, here we have a patient who we're going to say has a bowel obstruction, um, and there's the transition point, right? It's a mechanical type.
[16:03]But either way, things aren't moving along. If things aren't moving along, then the back pressure from all of this kind of obstruction point causing proximal distension, will cause some of the fluid to start backing up.
[16:17]And you'll have this retrograde expulsion, if you will, of intraluminal contents. So then what's going to be the effect here is the result is you'll have some retrograde expulsion.
[16:31]You know what that's a fancy word for it? That's a fancy word for vomiting. So these patients will have pretty significant vomiting.
[16:38]And when they have this intense vomiting, they're going to vomit up multiple contents. One of that is going to be lots of water, electrolytes.
[16:49]And so some of the things that they are going to lose is they're going to lose a ton of, there's going to be decreased in the amount of water and sodium loss.
[17:09]That right there in itself is going to contribute to hypovolemia. So this is one of the reasons why these patients will become hypovolemic.
[17:20]Now, when a patient has hypovolemia, what are some of the ways that these patients could look? Well, I think it's pretty straightforward is that if you have a lot of this loss of fluid, they may present with a decreased skin turgor.
[17:33]They may present with some tachycardia. They may present with some dry mucus membranes, right? They may even present with some hypotension.
[17:40]These are common features of hypovolemia. And I think that's one of the first things to be able to look for is, do they have any flat jugular veins?
[17:49]Um, do they have any decreased skin turgor? Do they have any dry mucous membranes? Do they have decreased urine output, tachycardia, hypotension? These are things to look for.
[18:00]The other mechanism that explains their hypovolemia, which is really interesting, is when you have this actual distension, what's happening here is, this wall distension, so this bowel distension, what it starts doing is it actually starts leading to compression, right?
[18:10]So you're going to have this bowel wall distension and what it's going to do is it's going to start compressing some of the structures in the actual bowel wall, like the veins and the lymphatics.
[18:29]And as a result, you'll develop a lot of bowel wall edema. So that's the other thing is that you're going to have bowel distension, which presents as, well, then lead to bowel wall edema.
[18:44]Because imagine here, whenever this bowel is becoming like significantly stretched because of all of this distension here, because of all this fluid and intraluminal contents, inside of this brown structure here, there's going to be lymphatics and veins, and they're being compressed.
[19:00]You can't drain things like fluid and blood out of the actual bowel wall, so it'll become edematous. If you have a super edematous, let's kind of like represent that here with kind of thickening up now, we're going to thicken up this puppy.
[19:20]This bowel wall is much more edematous and swollen. If it's much more edematous, what do you think's going to happen? It's going to make it really hard for fluid to be absorbed.
[19:29]So now the absorption and the movement of fluid from the bowel into the actual bloodstream is going to be inhibited. So this will be decreased fluid absorption as the result.
[19:40]So there'll be some decreased fluid absorption. The other concept is that if you have decreased fluid absorption, you're not bringing water and sodium and all these things into the bloodstream, what's going to happen to the volume within inside of your bloodstream? It's going to decrease.
[19:57]So these patients will develop hypovolemia because of that as well. You know what else, with all that bowel wall edema, you know what else happens is that it actually causes more fluid to be secreted into the actual from the bowel wall into the lumen.
[20:13]And so this is another thing is that you will actually also increase fluid secretion. And decreased fluid absorption, increased fluid secretion, which will lead to the formation of hypovolemia.
[20:53]In combination with water and sodium losses from vomiting. So look for that as a potential thing in these patients to be super dry.
[21:03]Decrease uh, skin turgor, dry mucous membranes, tachycardia, hypertension, flat jugular veins.
[21:10]The next concept here is when these patients vomit, they're not just vomiting up water and sodium. They're also going to be vomiting up other types of electrolytes.
[21:19]And one of these are going to be potassium. So there's going to be an increase in potassium loss.
[21:23]What is that called whenever you have low potassium? Hypokalemia. So these patients can also develop hypokalemia. All right.
[21:30]So we have hypokalemia because of the increased potassium loss. The other thing that they're going to lose is they're going to lose a lot of protons.
[21:39]In their stomach acid. So if you have especially if you have a small bowel obstruction, you're going to be vomiting up large amounts of hydrochloric acid. And so because of that, they'll lose lots of protons.
[21:50]So there'll be an increase in their proton loss. And that increase in proton loss will lead to what happens? If you're spitting out protons, you're going to have less of those protons present within the bloodstream.
[22:02]So less protons means the pH will go up, and it's a metabolic cause, not a respiratory cause. So this is called metabolic alkalosis.
[22:16]All right. So out of this, if a patient comes in, the things that you will be able to somewhat identify are going to be signs of hypovolemia, such as tachycardia, flat jugular veins, decreased skin turgor, dry mucous membranes, tachycardia, hypertension.
[22:31]You're not going to really see any features of these generally, unless they're super, super severe. These are more laboratory findings. This is more of a clinical finding.
[22:40]Okay? So look for that in these patients. Hypotension, tachycardia and dry kinds of physical exam findings. Once we've done that, the other big complication here that I think is really important is bowel ischemia.
[22:53]So whenever these patients have all of this obstruction here, again, there's going to be distension of the bowel wall. This distension of the bowel wall, one of the first things that actually starts happening is again, you compress the veins and the lymphatics first as you have increasing intraluminal pressure, right?
[23:13]So as there's higher intraluminal pressure, you're going to compress the veins. And then what else will you compress? You'll compress the lymphatics.
[23:22]The bowel wall becomes edematous. But as the intraluminal pressure really, really rises, so we continue to develop more and more ischemia of the bowel wall, there's more destruction of the bowel wall.
[24:00]And now these areas of ischemia are very weak and susceptible portions of the bowel wall. If you get the point, right, there's areas of necrotic tissue because of the prolonged ischemia.
[24:44]The complication that can arise from this is what's terrifying. Because naturally, let's actually use this. There is bacteria that are a part of our natural GI flora.
[25:00]And naturally, our GI wall is really good at preventing things from translocating. But if it's now damaged and it's lost its natural barrier function, what's going to happen? These bacteria can translocate across that ischemic area.
[25:12]And so if a patient experiences something called a bacterial translocation, this can cross the actual gut wall and get into the bloodstream.
[25:22]And if this gets into the bloodstream, what's going to happen? These patients can develop bacteremia and sepsis. So the thing that can potentially arise, is this can potentially increase the risk or stimulate the formation of the patient becoming septic.
[25:37]How does sepsis generally present? Well, generally, it can present in a couple different ways. One is they may have fever, they may have tachycardia, they may have an increased white blood cell count.
[25:48]And then eventually they can kind of go downhill and develop hypotension and features of shock, multi-organ system dysfunction. So I think this is one of the scary things about bowel wall ischemia.
[25:59]Another thing that's actually helpful and they can try to test you on this for the exam, is that whenever tissues are screaming because they're not getting oxygen, they kind of kick into anaerobic respiration.
[26:09]And they pop out this molecule that can kind of be somewhat indicative of ischemia. And so here, this tissue here, it's going to start pumping out, it's going to kind of kick into anaerobic respiration, and it'll pump out molecules called lactate.
[26:24]And so whenever you see a patient who has a bowel obstruction and then their lactate starts climbing, that is a really an ominous sign that they may start beginning to develop bowel wall ischemia, and they're a high risk of sepsis, so you have to watch out for that.
[26:42]Let's say that we go to the next step. Patient, you know, develops bowel wall ischemia. But then what happens is, the intraluminal pressure continues to rise and we come to this last scary particular issue here.
[26:53]So now, bowel wall ischemia, patient can develop sepsis, can develop increases in lactate. But what if the intraluminal pressure continues to rise?
[27:01]We continue to develop more and more ischemia of the bowel wall. There's more destruction of the bowel wall.
[27:12]And now these areas of ischemia are very weak and susceptible portions of the bowel wall. And if the pressure rises up enough, it may cause this portion to perforate.
[27:26]And if these do perforate, now you create an opportunity for everything that's in the actual bowel lumen to escape out into the peritoneum. What is this called? Perforation.
[27:41]So the next thing that can potentially arise here is these patients can develop what's called a perforation, a bowel wall perforation. Now, the scary thing about a bowel perforation is that you this can look a lot of different ways, right?
[28:22]So we said that bacteria could spread in the example above that it could translocate into the bloodstream. In this situation, it's going to translocate, but it's going to translocate into the peritoneum.
[28:35]Now, the things that are really helpful here is that peritonitis usually will present with findings of peritoneal finding. So, for example, you want to watch out for severe abdominal pain.
[28:44]You want to watch out for guarding. You want to watch out for rigidity. You want to watch out for rebound tenderness. So when you press into their abdomen, take your hand off, it causes intense pain.
[28:56]So when a patient has peritoneal findings and on top of that features of bacteria leaking in to the peritoneum and causing inflammation, like fever, and increased white blood cell count, this should lean more to the feature of a bowel perforation with peritonitis.
[29:40]The other thing is when you perforate a bowel, not only does bacteria leak out here, guess what else leaks? Air. There's going to be air naturally within our bowel.
[29:50]So now they're going to be bacteria that actually leak out. There's going to be air here. Let's actually be cool here, and we'll, we'll put some like, I don't know, some like circles here.
[30:02]This represents air. And this also will leak out. What is it called whenever air leaks out into the peritoneum? It's called a pneumoperitoneum.
[30:11]So another potential finding here that you want to watch out for, it's not just peritonitis because bacteria leaks out and causes inflammation and infection of the peritoneum, but watch out for air that leaks into the peritoneum. And this is called a pneumoperitoneum.
[30:28]The reason why I'm telling you this is when a patient comes in with a bowel obstruction, usually the the significant fear is these two, bowel ischemia, bowel perforation. Often times, you're training their abdominal exam to see if it gets worse.
[30:41]If it does, it could lead to ischemia. If their lactate climbs, it definitely suggests ischemia. Then watch out for risk of sepsis.
[30:47]If their abdominal exam becomes significantly worse with findings of peritonitis, you're concerned about bowel perforation. And one of the big things here is that sometimes what can really help to seal that diagnosis is that air leaked into the peritoneum, and it can be visible on actual radiographic images.
[31:04]And that's why this is important. Now let's move into the next step here, which is talking about how do we diagnose bowel obstruction?
[31:12]The next thing that we have to talk about here, after we've kind of gone through the bowel obstruction, is how to really diagnose it. How do I know if it's a small bowel obstruction? How do I know if it's a large bowel obstruction?
[31:20]How do I know if it's a paralytic ileus? How do I know if it's maybe even potentially a uh, a Gilvie syndrome or colonic pseudo obstruction? Well, first thing is again, you have to ask yourself the question because this is the most upmost importance here, is did they perforate?
[31:33]So did they come in originally with cramping abdominal pain, abdominal distension, vomiting, having out of bowel movement in a couple days and all of a sudden, they present with searing abdominal pain?
[31:43]They present with rigidity, guarding, rebound tenderness, reduced bowel sounds, fevers, leucocytosis, maybe they even a little hypotensive.
[31:50]I'm scared. I'm scared that they perved. I'm scared. So I needed to get an abdominal x-ray, look to see if I see air underneath the peritoneum. If I do, and they're hemodynamically unstable, signifying that they may be coming septic a little bit, then I need to take them right to the OR and I'll do an intraoperative diagnosis. I'll find the actual area where they perved and I'll treat it accordingly.
[32:09]If they do not have a pneumoperitoneum, and they're not hemodynamically unstable, and I see on the abdominal x-ray that they have dilated bowel loops.
[32:17]And I see a lot of air fluid levels indicating that there's probably a transition point, then I'm definitely scared that they have an bowel obstruction. And the most definitive way to diagnose a bowel obstruction is to get a CT of the abdomen and pelvis.
[32:28]When you do this, it'll really help you to identify if it's mechanical or if it's a functional obstruction.
[32:35]Often times an abdominal x-ray can do that, but CT abdomen and pelvis will give a little bit of a better idea. For example, do I see a transition point? Do I see an area where I see the obstruction?
[32:46]And I see the narrowing of the bowel wall with proximal distension and distal decompression. If I do not, that kind of suggests more of a functional bowel obstruction.
[32:55]Also, make sure that you're listening to their abdomen. When you auscultate, do you hear absent bowel sounds because absent bowel sounds indicate that they're probably more towards the functional obstruction side?
[33:05]Because usually in your structural obstructions, you start off with hyperactive, and then eventually you progress to almost hypoactive or absent bowel sounds.
[33:14]So again, absent bowel sounds with the absence of a true transition point suggests a functional obstruction. Then you just have to determine where is that point?
[33:22]Is it involving only really the small bowel, maybe a little bit of the colon, or is it only involving the large bowel? So if I see dilated colon, cecum is greater than 9 cm, the colon's greater than 6 cm and I see a obvious transition point.
[33:40]It's likely a large bowel obstruction. And again, that's usually going to be in the form of like colorectal cancer or some type of volvulus. So here you can see that there is an obvious dilation of the distal colon, parts of it here as well.
[33:55]And then it's kind of cutting off somewhere here. So I notice that there's definitely a transition point somewhere in this vicinity and I have distal decompression because I can't really see the bowel a little bit further down here.
[37:06]Again, here's another point here where you can see again, very large distension of the large bowel here, distension of the large bowel here, and at some point around this vicinity, there is some type of transition point with distal decompression. So if I go the other route, I have a patient that I now think has an ileus that'll really only be dilated small bowel, predominantly. So I'll look and I'll see that the small bowel is greater than 3 centimeters at multiple points.
[34:19]Maybe they have some colon involvement. Maybe they have some parts of their colon that are greater than 6 cm. Either way, if they have both, and I see no mechanical transition point, I see absent bowel sounds on their on auscultation, I think it's probably a paralytic ileus.
[34:35]And here you can see that they have multiple areas of dilated small bowel loops, and they even have a little bit of dilated large colon here too. But there's no transition point with air fluid levels.
[34:44]That really more likely suggests that they have an ileus. And again, here's a CT scan that would identify an ileus here.
[34:52]You have small dilated small bowel loops and maybe even some dilated large bowel loops. But again, no mechanical transition point.
[37:51]How do we treat these? For mechanical bowel obstructions, you have to then kind of, again, alleviate the area of where the obstruction is occurring.
[37:58]And sometimes that may require surgery. However, if we don't require surgery, it's nice to kind of supportively take care of these patients. So often times that's a lot of supportive care.
[38:09]So first thing that we're going to do is try to decompress the bowel. And this is going to be done, again, non-surgically. So how do we do this?
[38:17]Often times in patients who have small bowel obstructions, they have a lot of fluid and food and fluid and air that are built up in their small bowels, and it's causing a lot of distension, a lot of vomiting, a lot of nausea, a lot of abdominal pain.
[38:26]Often times, it's best to put an NG tube in, and suction out a lot of those contents. And that'll alleviate a lot of the vomiting, a lot of the abdominal distension, and a lot of the abdominal pain.
[38:37]It's also best to avoid anything going down the oral cavity until they've started to resolve that obstruction because if not, you're just going to cause again, more air, food, and fluid to build up, cause more abdominal pain, more distension, and more vomiting.
[38:50]So keep them NPO, decompress their bowel by suctioning out some of the contents when you put the NG tube in, and then replace the fluids that they're not taking in from eating and drinking with IV fluids until they've resolved.
[39:04]In partial obstructions, especially ones that are due to a lot of edema, you can give them a medication called Gastrografin. Gastrografin may be something that you take in, and what happens is it moves through the actual bowels.
[39:17]It can generate a little bit more of an osmotic gradient and it can pull fluid out of the bowel wall. So you know the bowel walls get super edematous as you compress the veins and as you compress the lymphatic vessels.
[39:26]And so the bowel walls can get really edematous. If I pull some of the water from that edematous bowel, I may be able to reduce the extent of the obstruction.
[39:35]And so sometimes in partial obstructions, or Gastrografin can actually make its way through, it can pull some of the water in that vicinity. If it's a complete obstruction, it's not going to help and actually could make it worse.
[39:46]So again, Gastrografin a little bit more beneficial for those partial obstructions. The next one is what if the patient does have bowel ischemia?
[39:56]In other words, I see that they have an intense elevation in their lactate. Maybe they're developing some concerning signs of sepsis, or they perved.
[40:03]In these particular situations, often times, you're going to have to take these patients to do some type of surgical intervention. So one is you open them up or you do a laparoscopic study.
[40:34]And you go in and you find the area of where the obstruction is, and then you kind of remove that obstructed material. Maybe it's clearing off the adhesions, maybe it's freeing up the hernia from the actual defect in the abdominal or pelvic wall.
[40:48]Maybe it's kind of taking a intussusception and trying to improve that or pull that untilescope that that area. Um, if it's a colorectal mass, often times that may resolve, uh, that may require some type of like surgical resection.
[40:59]If it's a volvulus, sometimes you can actually do an endoscopic procedure where you go in and you actually detorse that area. So it is important to remember that surgical interventions may be required or endoscopic interventions, especially if they have a volvulus, you can go into the particular vicinity of where the volvulus is and help to detorse that area.
[41:20]Now, in patients who have functional bowel obstructions, this is not something that you have to require any type of procedure unless they do perforate or they develop bowel ischemia.
[41:29]Often times it's the same thing. You decompress their bowel, you give them IV fluids while they're not eating or drinking. You maintain them not eating and drinking anything until their bowel is actually healed.
[41:38]And then if they have a lot of vomiting, nausea, abdominal pain, distension, put an NG tube in, suction out some of that material and that'll help to relieve the abdominal pain, the distension, the nausea and the vomiting.
[41:48]The other thing that may help, especially in patients who have a lot of um Ogilvie syndrome, they have a lot of air and food and fluids that are kind of like sitting particularly in their large bowel.
[41:57]You can put a rectal tube in and it'll decompress that distal bowel and that may be somewhat helpful, but more particularly in Ogilvie syndrome. It's important to remember that bowel motility is the problem.
[42:07]In these, it's obstruction, and you have to fix the obstruction. In this, it's motility. So improve their motility.
[42:14]Often times you can do laxatives, this may help a little bit. And then sometimes in patients who don't respond to things like Senna or things to um, like polyethylene glycol or maybe lactulose.
[42:24]Then you can go to the route of Neostigmine, which is more of a, uh, it kind of it helps to particularly increase the acetylcholine in the synapse of the smooth muscle and increased contraction of the smooth muscle. So it'll help to move things along, but this is usually this is more of your last line medical therapy.
[42:39]In patients who have severe bowel ischemia due to the ileus or Ogilvie, or they perve.
[42:45]In this particular scenario, you actually do have to do a surgical procedure where you go in and actually close off the area of perforation, maybe resect out the actual disease segment of the bowel, and that's really important to remember when you would do this one. All right, my friends, that's bowel obstruction.
[42:58]I hope it made sense. I hope that you guys really did enjoy it and like it. And uh, as always, thank you, love you, and until next time.
