Evaluation of the Pediatric Abdomen-Who needs a CT for Blunt Abdominal...

Can I have control of the slides? See, or maybe just advance. Oh, yeah. So I'm gonna present uh two cases, and they're patients from the same vehicle and uh try to highlight what I think are salient points about um who needs abdominal imaging and uh who you might be able to safely avoid imaging in. So the first patient is a 6 year old male. He was a restrained backseat passenger in a motor vehicle collision. His, uh, car hit a tree head-on. Uh, there was no reported loss of consciousness. He was, uh, by report from EMS hemodynamically stable en route. In our, uh, trauma system, we have a tiered trauma activation. Uh, Level A is the, um, the highest level. These are the typically the unstable patients or the intubated patients, patients that have a need for emergent intervention, and then, uh, level B, uh, are typically, um, called that way, um, based on their mechanism of injury. So this patient was a level B activation on primary survey. His airway was patent. He had a respiratory rate of 27, Blood pressure was 111/81, heart rate 131. By Broslow, he was roughly 20 kg and had a GCS of 15. On the secondary survey, he had some mild midline cervical tenderness to palpation. He had uh some moderate abdominal tender tenderness to palpation over a, um, obvious seatbelt contusion. And then, uh, in general, the abdomen was soft, maybe slightly distended, but no obvious peritoneal signs. Next, This is uh a picture of his abdomen. You can see here highlighted, uh, the seatbelt contusion. The head is over here to the left, uh, of the screen, and here the umbilicus, uh, pretty standard, um, seatbelt contusion, uh, that we see, uh, periodically in the, uh, children, particularly if they're, um, not properly restrained. And let's see, next slide. Can we advance? Or maybe not. So that I'll just continue to talk while we're fixing the slides, but the second patient in the vehicle was an 11-year-old female. She was a restrained backseat passenger, same vehicle, car versus tree. She was found slumped under the driver's seat. Uh, she did have a reported loss of consciousness, also was hemodynamically stable en route. And presented again as a level B trauma activation. Primary survey, her airway was patent. Her respiratory rate was 28, Blood pressure 84/36, heart rate 118. 35 kg roughly and GCS of 15. She also had some mild, uh, midline C-spine tenderness to palpation. Uh, she had on, uh, examination of the oropharynx, several fractured incisors, a minor lip laceration. Her midface was stable, and a fairly normal abdominal examination. Uh, next slide. So, um, questions, uh, for co-surgeons or for the audience. Um, how would you have, uh, considered this patient in terms of, uh, activation level? Do you routinely order labs in the trauma bay when you're, uh, doing an assessment of this type of patient? Uh, are these patients, do you order plain films? And if so, what are they? Um, in your center, are they, the labs and imaging standardized by the activation level? Uh, or is it dependent on, um, whether the ED physician or the surgery resident or the adult trauma surgeon or the trauma surgeon happens to be at the bedside. And then finally, um, is this somebody that you would get a fasting? And if you do fast, who performs the fast and who interprets it? And does it really impact your management decision? Uh, so maybe we hear from the panelists and Rich if, um, there are questions or comments, uh, I want to hear them. Yeah, great. So, um, we do have a, uh, the first comment I had was just, uh, that yes, abdominal ultrasound. I don't know. I'm trying to get an answer whether that was for both and yes. They said the abdominal ultrasound for both and that came from, uh, Colombia actually. Um, so, um, Roberto, why don't, why don't you let us know what you, you know, from the adult standpoint, where, why don't you start and I'll kind of add in as well what I think. Certainly, um, now we're saying from an adult perspective, uh, seeing this child, yeah, that comes in, yes, so, I, I do think that it matters as to who sees the patient. Um, honestly, I think that, uh, for the most part, um, our, my, my partners and the trauma surgeons, if we get to the bedside where I think a lot more conscientious, uh, about being conservative with regards to CT scan. Um, and whereas I think we're trying to teach our ER emergency room colleagues, uh, to be a little bit more judicious and when the UCT scans. Uh, and so, I think if one of us gets to the bedside first, we're, we'll, we'll sort of triage and guide whether this kid gets a C, this child gets a CT scan or not. Uh, but if we happen to show, you know, we're in the OR, we get tied up, and we don't get there for 30, 45 minutes, the CT scan is probably already gonna be done for us just because of the seatbelt sign. Um, and I'll tell you, I think one of the interesting things is, there is a seatbelt sign and there's a seatbelt sign. This, this, this is a perfect picture of a seatbelt sign, but frequently, and I think one of the challenging ones is when a, a child comes in and they have bilateral iliac crest seatbelt sign. I think that should be managed somewhat differently than a true seatbelt sign, which is clearly across the abdomen from a surgeon's perspective. I think that's a great point, Roberta, and hopefully we'll kind of get into a little more of that discussion because that's certainly a piece, even at a peed center that comes up with, with residents. Um, when do you, what's a seatbelt sign, a little abrasion over the iliac crest. That's probably not the same as that picture that, that Chris just showed us that I think raises all of our concern a little bit. Um, higher. So I think in our center, cause these would both probably be kind of mid-level activations, um, cause we do mostly based on physiology, so their physiology seemed pretty normal, um, in both of these kids. Um, we don't routinely get labs on, I mean, we get type and screen and a, and an ISA on, on everybody, but we don't routinely get, which I think you'll talk about a little more, kind of the traditional abdominal labs on everybody. Um, we generally just get a chest X-ray, um, as our routine. We don't, uh, we don't routinely get pelvic films, um. If I had to kind of, just at this point of the discussion, I'd say we'd probably CT the lap belt kid and we'd probably either simply observe or get some labs on the, the second child. Fast is a whole discussion that I think we'll get to, get into as we go forward a little more probably, but um I don't think I would fast either one of these kids right now. Roberto, do you selectively fast or do you fast everyone and does it depend on activation level? It uh depends on activation level and really in, in children, we tend not to fast, most children because I, I, I do think that uh the data does not support fasting of children, um, as well as it does uh for adults. And I think that has to do with the fact that in order to find a good amount of, in order to do a good fast and find blood, you need to have, they say, the literature says really that about 200 cc's of blood. Um, have to be in the abdomen. Now, we're not even talking about the retroperitoneum. The retroperitoneum is a whole another ballgame. That's very challenging in and of itself. Um, most fasts are not gonna be able to pick up, uh, a significant amount of retroperineal blood. Uh, so 200 cc's of blood, especially in a young kid, is a lot of blood. Uh, and they're typically not going to, uh, present, uh, in a stable situation if they have that much blood in their abdomen. So by and large we do not fast children, but in adults we do. We're pretty liberal with level one, so our level one activations or highest activations we do, uh, we use fast quite a bit. Great. So we'll kind of get more to that. There's one other comment from, uh, a couple. There are a couple of people that said we don't do fast for our pediatric patients, um, as well, um, but that sometimes it's done by the, the ED physicians regardless. But as the pediatric surgeons answering, say they don't, they don't do it. So why don't I let you move along, Chris, and we'll kind of talk more. Can we get the next slide, and I will say at our center, uh, all the patients get a fast, and that's largely because the, um, residents cover both adult and Pete's trauma. And so they're walking across uh to the PDD and basically, um, continuing the same practice that they've been uh trained to do. So the first case, the brother with the seatbelt contusion, hematocrit was 37, his AST was 49, the lipase was normal, uh, base deficit and lactate were not performed, and he had a normal chest X-ray. Uh, next slide was the sister. Uh, she had a hematocrit of 42, and AST of 222. A normal lipase and, uh, again, base deficit and lactate not performed. And on chest X-ray, she had some uh very small, uh, pulmonary contusions. Uh, so, uh, next slide, um, uh, so the kind of the follow-up questions, we've alluded this a little bit is who needs, uh, an abdominal, uh, CT. So it sounded like, uh, Roberto, you probably would have scanned the kid with the seatbelt contusion. Would you have scanned, uh, this little girl? With the elevated AST, uh, and pulmonary contusions, but otherwise fairly unremarkable physical exam. Yeah, I, I think we would, we would scan that child as well. And how about you, Rich? So I, I think based on the, the AST would make me probably scan that second child as well. I would have scanned the first child regardless based on that abdominal bruising. So the labs on the first child don't really change my opinion at all, um, but the labs on the second child, I think do influence, uh, my decision. All right. And so those are kind of my follow-up questions. Question 2 is hemodynamically stable patient with tenderness and a seatbelt contusion. I think we would all agree that that patient likely needs a scan. And then, uh, there's some data I'm gonna present um and follow up about screening labs with the idea, uh, that you may be able to avoid CT in some patients, uh, by ordering, uh, imaging. And then finally, we didn't present this patient. What if you have an intubated patient that had a serious MVC but has a normal physical exam and all their labs are normal, Does that patient need a CT scan? Roberto, you want to take that first. We do have some, most people. You know, we heard from a couple of people in the chat that said they'd CT both patients at this point, um, and then if the patient's intubated, they use they would abdominal CT. So Roberto, you want, what would you guys do? Yeah, you know, I, I think one of the things that frequently gets glossed over is mechanism of Injury. Uh, if you have a significant mechanism of injury, then, uh, I would be more liberal with scanning a child that, um, you know, uh, that, that presented is, and is intubated and they can't get, you can't get a reliable physical examination, um, if they have a significant mechanism of injury. If they had a mild injury and they may have aspirated. Um, and they may have a head injury, but not necessarily, you get no other measures of injury that they had a blow to the abdomen, they didn't get kick punched or, or anything of that sort, then I don't think you necessarily need a, an abdominal workup, but I would, I do think that's where abdominal, uh, labs. Come in. I think your AST, ALT, and lipase really come into play. And I would say that the lactate plate, lactate-based deficit also plays a major role in deciding whether a follow-up CT scan would be required down the road, uh, maybe not necessarily immediately, but within the, you know, next hour or when the labs come back. All right, so I agree. I mean, I, I think the, you know, I think the intubated patient is certainly the challenge. I think what you had in quotes on that prior slide is quote serious, I think, is part of that discussion, how worried am I based on the mechanism. I think it's important though. I don't know that everybody that's intubated from uh NBC or other reason absolutely needs a CT, but I think you need to weigh those pieces. Sure. All right, so we did scan the patient um with a seatbelt contusion and this is, there are two cuts, they're very similar cuts, but representative cuts. So, uh, I don't know, can you guys see me moving the mouse over the duodenum? Uh, there's some thickening here around the duodenum. The actual, uh, read was that there was some fluid in the lesser sac and that the radiology, uh, attending, uh, was concerned about a posterior gastric. Uh, wall, uh, perforation. There's fluid in both paracolic gutters, but not a large amount of, uh, free fluid. There was no free air and there was no contrast extravasation. Uh, so that, that, um, was the film on the boy, on the brother. And then, um, the sister had an abdominal CT scan. She's the one we scanned, uh, based on, uh, her elevated AST and the pulmonary contusions on the chest X-ray. She had a CT, uh, scan of the abdomen and it was normal. Uh, so I'll get to what we did in just a moment, but, um, if we can advance the slide, I'll present some of the data, uh, uh, that we've collected on, um, blunt, uh, abdominal trauma with the idea that we may be able to avoid CT and potentially 30 or 40% of the patients that present with a serious, uh, mechanism of, uh, injury. So can you go to the next one? Um, so, uh, Rich and I, uh, participated in a collaborative, uh, group. Uh, it involved 14 pediatric level one, trauma centers, and, uh, this was the focus of our study. Next slide. Uh, you know, as we discussed, um, CT scan is commonly used for the evaluation of children, um, despite the fact that, um, there's a pretty low incidence overall of intraabdominal injury. There's some cost associated with CT. And then, uh, the big concern is with uh the risk of radiation-induced, uh, malignancy. Uh, so next, So, um, several studies in the past have suggested that things like plane films and labs performed in the trauma bay might be useful to stratify children that, that might have an intraabdominal injury. Our goal was to avoid abdominal CT in the low-risk population. And what we did is we collected data prospectively for a year in the trauma bay. We looked at the mechanism of injury, the patient's vital signs, uh, pertinent history and physical examination. Their, uh, labs, urinalysis, chest and pelvis X-ray, and their fast exam. Um, in our study, in previous studies, uh, the data is limited by the retrospective or single institutional, uh, nature. Uh, so, uh, we set forward to do this, uh, as a, a collaborative group in a prospective fashion. In addition, as Roberto uh may, uh, discuss, um, you know, as we move forward, there are a couple of adult papers that looked at PACT and they suggest that PACT, at least in the adult population, may be more cost-effective and miss, uh, fewer injuries, um, and so, it seems to be this is pretty common in adult trauma centers. Next slide. So, um, one study that was recently performed was by a group, uh, called PCARN. This is a group of, uh, emergency physicians. It involved 20 institutions, and they did a prospective multi-institutional study, and their primary outcome was intraabdominal injury requiring an acute intervention, which they defined as urgent surgery, angiography, or transfusion. These are the patients in their mind that they really cared about, the ones, uh, that needed an urgent intervention. And because they had concern that uh labs and imaging weren't standardized across the centers, they really only looked at history and physical exam elements. And the good thing about the pecan rule is it's great uh for predicting um patients that don't need urgent surgery, angio, or transfusion, but this is only about 2 or 3% of the patients that we see. And the concern is that the pecar rule misses a lot of clinically relevant injuries, primarily solid organ injuries, which we might admit or do serial exams or labs on, uh, or at least consider activity restriction. So we set forth to look at a rule that might, uh, capture all the, um, intraabdominal injury. Next slide. So again, the purpose of our study was to derive a clinically prediction rule and use all the, the data in the trauma bay uh available to see who we could potentially avoid a CTN. Next slide. So again, 14 uh institutions, this was only involved patients with blunt trauma. We focused just on patients that arrived within 6 hours of injury, so these weren't delayed presentations. We excluded patients that had a CT scan prior to arrival or a patient that had an isolated head injury or an uh mechanism of injury focal to the extremity. Next slide. Oh, sorry, back one. So again, collected data, did univariate and multivariate analysis, uh, used a Gi splitting technique. To account for uh missing variables and excluded any variable that wasn't collected at least 70% of the time. Next slide. Uh, so over a year, we collected data on 2,188 patients. The median age, uh sorry, the mean age was around 8 years of, uh, age. As you can see from the pie chart, these were all patients that had pretty significant injury, motor vehicle collisions, pedestrian or bicyclist struck by an automobile, an ATV, fall from a height, uh, greater than 10 ft, uh, or bicycle collision. Within the population, about 12% had an injury and 3% had an injury requiring an acute intervention. You can see the numbers, the breakdown for surgery, transfusion, angiography, and death. So death from intraabdominal injury was pretty rare in our population, and overall, 45% of the patients underwent a CT scan and very impressively, amongst the 14 centers, the range of CT scan use ranged from 4% to 96% in a similarly injured population. And, uh, in addition, 75% of the patients were admitted. So these are patients that have a lot of uh coexisting injuries, primarily orthopedic and, uh, and head injuries. So it's a pretty injured population, but most of the injuries aren't intraabdominal requiring intervention. Next slide. So what we came up with um by recursive partitioning was a rule, and this is a chart that ranks the variables that were most um predictive of an intraabdominal injury. Uh, the five variables that had the greatest predictive value were an AST greater than 200. An an abnormal abdominal physical examination, an abnormal chest X-ray, a patient complaining of abdominal pain, and abnormal pancreatic enzymes. And what we identified was that in 34% of the patients, uh, there was a, a very low-risk population that had a 0.6% risk of intraabdominal injury and 0% risk of an injury requiring intervention. So this would suggest Uh, that you do have a population, uh, that even in patients with significant mechanism of injury, with a screening history, physical exam, and some basic labs and imaging, you could safely avoid CT. Uh, overall, our prediction rule had a negative predictive value of 99.4% for intraabdominal injury and 100% uh for an injury requiring an intervention. Uh, again, Uh, a low-risk population, uh, was suggested. Looking at, um, the abnormal variables, so this is, uh, a table showing, um, the risk of injury and injury requiring intervention based on the number of abnormal variables. So if you had just one variable that was abnormal, you still had a fairly low risk of injury, 4.5%, uh, or injury requiring an intervention. And, uh, as the number of, uh, positive variables increased, as you might expect, the, uh, risk of an injury or injury requiring intervention increased, uh, pretty significantly. Chris, can I ask a question on that? Yeah. Did, is, was there any difference or did you look at any difference as to which of the, you know, which was the one factor, you know, or was that the average range across? Any one of the, the variables. That's, so that's a really great point. Um, so that, that's the average range for one positive variable, but when you look at the odds ratios for the variables, and just to make the charts easier to read, they're not, uh, in there in, in minute writing, but, um, we did calculate an odds ratio for each variable, and interestingly, the abnormal physical examination, like the patient I've presented with the seatbelt sign. is the variable with the highest odds ratio for an injury requiring an intervention. The elevated AST, the AST greater than 200, is the variable with the greatest risk of an injury that did not receive an acute intervention. And so this is why, uh, we feel like a prediction rule that includes labs is helpful, uh, in identifying those patients, primarily liver injuries, but there were some spleen, kidney, uh, and kidney injuries and some Uh, other injuries like a duodenal hematomas and, and those sort of things that didn't require surgery that were identified, the rule was more sensitive for all injury including the labs. Uh, so this is, um, a chart with the same five rules, and this is in the order that, uh, you as the practitioner, uh, identify abnormal findings. And, and we thought this actually was the most practical way to look at the rule, uh, was to sequentially, um, go through this. Does the patient have a complaint of abdominal pain? Uh, yes, um, you know, these are your individual risks, uh, for injury and injury requiring intervention. And then here, it should really say no or cannot assess. So we didn't a priority exclude patients that were intubated. Or at a GCS less than 14, that was another difference between our prediction model and the PCCAR model. And it goes uh uh forward uh as you typically find the information, the trauma bay. We often get a chest X-ray pretty rapidly, and then sometimes it takes anywhere from 20 minutes to an hour to get your labs back. And it could be even longer depending on uh your center, but I think you can see from this, um, that even if you're waiting on labs, uh, your risk of, um, an injury is still pretty low. Uh, and then, uh, eventually, you get to that very low-risk population where we can say, hey, these patients really don't need a CT and they probably could go home if they don't have, uh, any other, um, injury, and that's this very low-risk population. But it kinda, uh, I think warrants consideration. Of, uh, just waiting to decide on the CT for the labs to come back if there's no compelling reason, uh, to get a CT and if you kind of pull these populations, you really have a 55% population or more than half of the patients that come in that have a less than 5% risk of an injury. And a less than 0.3% risk of an injury requiring an acute intervention. So, I'm commonly asked, is there time to wait on the labs to come back? And I think the answer is in the absence of the first three variables, there's plenty of time to wait and decide unless there's a compelling reason. So in conclusion, you know, we found that uh previous prediction rules were limited by the retrospective or single institution nature or the fact that they didn't include labs. Uh, our goal as, as the surgeons is to diagnose all the injuries, not just those requiring intervention because we commonly admit these patients do serial labs and exams, uh, and, and often provide, um, information to the, the families and the kids about activity restriction. But overall, we do feel that it's pretty safe to avoid CT and the very low-risk population. Um, in terms of how the patients present, we found 97% had a normal blood pressure for age on arrival. So it's a pretty small population even with these mechanism of injury that require an acute intervention. So it's a pretty large group that you can consider avoiding CTN. And as I said, um, there's pretty significant variability between centers, so that would suggest that we can probably do this better. Um, and these are pediatric trauma centers. So if we look at adult trauma centers, we might see an even higher rate of CT. Sounds like Roberto is pretty, um, frugal, uh, in that, uh, but I would say, um, we get plenty of referrals that have been paying CT, so, That's not necessarily the mantra everywhere and there's plenty of patients that don't get seen at a trauma center at all. And I think the providers are just trying to figure out who needs to be transferred and uh who doesn't. And then finally, uh, all of these prediction rules require external validation, and uh we've done that in a, in a separate data set and found that the negative predictive, uh, negative predictive value is really high. So I feel like the next step, and hopefully Roberto will will get us to this is what are the limitations in implementing a protocol like this, uh, in an adult trauma center, at a combined trauma center, and a non-trauma center where we might, uh, make a more global impact on, on TT utility. So I'll just stop there and I think that's all I have. Uh, 11 question for you, Chris. Did you, one thing that is, uh, regularly done, I think with adults and we do with a lot of our, our kids as well is getting, uh, a pelvic X-ray. Um, and I, I, I think that that is, you know, the radiation dose is so low. Um, if it's negative, I think there's some, there can be some comfort in that there's not a significant injury. Now, if you've got a significant injury where you have a pelvic fracture or even a superior or inferior ramus fracture, I'm probably gonna be more likely to do a CT scan on that child regardless of what labs look like. Um. Did, did you incorporate that into your model? Did you look at that? And if you, if you did not, then why was that not part of the, the algorithm that you looked at? Just getting a plain, a plain film X-ray of the pelvis. Yes, that's a great question. So I didn't list all the variables that we, we looked at, but we did look at, um, whether a patient had a plain film for a suspected femur fracture, and we looked at whether a patient had a plain film. Uh, uh, of the pelvis. Um, and, uh, as it turned out, the pelvic, um, plain film didn't really add anything to the predict to the prediction model. The negative predictive value was 99.4%. So, uh, on multivariate analysis, it just, uh, kind of fell off, um, the algorithm. Uh, pelvic, uh, X-ray is one of those things. I think there's a lot of variability among centers. So, I think uh one of the challenges is that we didn't order a pelvis plain film on, on all of the patients, but in the end, I don't think it would have added anything to the model. I would say though, that's one of, one of those examples where if on a physical examination, you know, the patient has an unstable pelvis, so they have a tender pelvis. I, I certainly think you're gonna get a pelvic plane film in that case, and that may Uh, as you said, um, prompt you to get a CT, I think that, that's totally reasonable. And a patient that doesn't have any, uh, tenderness to palpation or an unstable pelvis, I don't think a pelvic plane film adds anything to the model. So, in, in our center, we would only get one, if we were concerned, uh, about, uh, a pelvic injury, um, you know, it's one of those questionable cases on On physical exam, you know, you might make the argument you don't need one if you're gonna scan them anyway, and I think, um, at least I see that with my adult colleagues that they've almost stopped doing pelvic plane film altogether because it doesn't, uh, affect their management. It's one more film to get, and they only get it on the back end if Ortho is asking for, uh, you know, inlet and outlet films or something like that because there's a, a fracture on, on CT and they want plain film imaging. So, Chris, that's, that's great. I mean, I think some of the comments are that people are either going to change their practice based on that or at least possibly change their practice based on, based on that data, so that's a start. So, we've, we're trying to look at actually implementing this. I mean, we're lucky to be part of the study, but now we're trying to say, OK, how do we, how do we use this? And some of the questions that I've gotten um from our residents or nurse practitioners, people that might be in the position to, to use this algorithm are, well, We have a lot of kids that when they first walk through the door, they complain of abdominal pain. Um, uh, you know, you then calm them down and that, that pain goes away. We also have kids that have some abdominal bruising and, and like we started to talk about earlier, well, what's, what's a seatbelt sign and, and You know, how do you use that? So what are your thoughts on, on that, um, as far as how to break that part out? Yeah, so that, those are, are both really good questions and Um, so, to be really clear, we're not looking for reasons to scan more patients, right? And so, uh, that, that's one of the challenges with the prediction rule is if someone, uh, doesn't read, uh, the, the whole paper or just looks at, you know, a snapshot of the algorithm and sees a complaint of abdominal pain, um, you know, we have a positive variable, we're gonna scan them. That, that's not the, the concept, and I would actually say, If you look at um those 5 variable charts and you, you get down the algorithm and you just take out complaint of abdominal pain, uh, that was one of the, the least predictive of the 5 factors. So if I had a patient that had 4 negative variables and a complaint of abdominal pain, I'd probably come back and re-exam, examine them, uh, later. And, uh, I think it would be safe to kind of wait to image that patient if you had no other. Uh, compelling reason, and I, and I agree, we often have patients that come in, they're kids, they're scared, uh, they may have distracting injuries, and, uh, so it can be a little, the history can be a little bit, um, uh, challenging. Uh, so I don't think, uh, complaint of abdominal pain alone should mandate a CT. That's, that's not the message. Uh, and I, and I agree it can be tough. And the follow-up question to that, remind me again, uh, what was the second thing? Yeah, so kind of what bruising. Oh, the bruising, yeah, bruising, yeah, so, um, if you really dig down in the manuscript, we kind of list what is an abdominal, uh, an abnormal abdominal examination, and when we say, uh, bruising, we're really talking about like handlebar contusions from a bicycle or an abdominal seatbelt contusion. Um, abrasion is listed, and that is, that is the challenging thing. And again, uh, I would say just as you said, not all physical exam findings are equal. Um, so it is the, it is the seatbelt contusion or the, uh, uh, handlebar contusion. The patient with peritoneal signs, those are the ones that, you know, definitely, I would say need an abdominal CT. If you just have a little bruising over the, you know, the iliac wing, or uh maybe there's a small abrasion uh near the costal margin, you know, those are ones that, uh, I, I, I would say those don't mandate a CT either, so there's still some need, uh, for judgment. And, um, you know, 75% of these patients get admitted. Uh, so if, if you have a patient that has um a femur fracture or, you know, a humerus or um they have um uh concussion or, you know, um Kind of a mild um TBI and you're gonna admit them anyway. It's a captive audience for you to do serial uh abdominal examinations on. So, you know, you don't have to scan those patients that have those abrasions because many of them are getting admitted uh to the hospital anyway. And I certainly think as I, as I stated, the patient that just has one positive finding, if they have a pretty reliable, uh, family and the only complaint is mild abdominal pain. These are ones that, you know, at some point in time, we might say, well, let's, let's let them go home and, uh, you know, if they live nearby and they seem reliable, we could, uh, you know, ask them to come back if it seems like something has progressed. Great. Um, so right now, I'm just kind of seeing if there's some questions. We have one request for the actual article, so we'll get that, um, you know, we'll get the reference out there. The, um, I think we'll move on. The other important fact that I think you alluded to, and I just want to make sure it's emphasized for our participants before we move on to Roberto. One yes answer doesn't mean you have to get a CT. You still have to use some clinical judgment. It's more importantly, everything's no, you don't need that CT, correct? Exactly. All right, so we'll move on to