All right, well, I'm first going to go over just a review of the guidelines that we published this past year. But I'd like to first just give a shout out to Rob. I mean, he's more than just the moderator. He's really the heavy lifter for this whole thing, this whole project. Tons of emails, doing all the work for the grant that supported this. So thank you to Rob, and thanks for calling me to let me talk. I have no disclosures. So here's my objectives. I'm going to first review the epidemiology and a little bit of physiology of life-threatening traumatic hemorrhage. I'm going to discuss the conference that we did and then identify key findings, not including TXA whole blood, which Phil will be talking about and Jen will be talking about research priorities. So we first had to define it, right? So what is hemorrhagic shock? Well, I'll let you read this definition here. So in addition to being a form of hypovolemic shock, we wanted to get across this concept of blood failure. So you see that point of inadequate oxygen delivery, hypertension and tachycardia, and then the inadequacy of cellular hyperperfusion to include the things that we typically see in shock. So kids are a little different than adults when it comes to hemorrhagic shock, right? Adults typically show hypotension earlier, and this has implications when we think about resuscitation. So you may have heard the adult concept of permissive hypotension. Well, you know, that may be a different—we may have to look at that different in children. So children have a profound ability to, you know, release catecholamines and maintain their blood pressure until about 30 percent of blood loss, and then they start showing hypotension. Hemorrhage is—in terms of causes of death, this figure illustrates just that children die from hemorrhage early. So typically within the first six hours is when you see most kids dying. It is a challenge, though, to study transfusion and massive transfusion in kids. So when you take all comers of trauma activations, only 3 percent of them are going to get blood. Of those, in terms of a massive transfusion defined around 40 mLs per kilo, only half percent. This compares to about—when you're looking at adults, about 8 percent of adults will get a blood product, and 3 percent of them will get a massive transfusion. So this makes studying massive transfusion in kids very difficult, right? It's hard to do a single-center study when you only have a tiny sliver of kids needing a massive transfusion. So there is a need for multi-center studies. And again, when you're thinking about all the recommendations that we're making, these recommendations are only applying to a small fraction of kids, right? You shouldn't be applying these recommendations to every trauma activation. So again, think back to that definition of life-threatening hemorrhage that I talked about in the beginning. So first, to set up the grounds of what does massive transfusion look at in kids. So Phil and this head of this study, the prospective study in children looking at massive transfusion. So this is not just trauma, but looking at massive transfusion activations in over 20 centers. Causes of bleeding were about 46 percent. Massive transfusions were for trauma, 34 percent, and the OR population in 20 percent were your medical bleeds. For the trauma population here, which we're focusing on, the average age was about 10. They're pretty severely injured as you can see by their ISS score. And majority of those were blunt injuries. So what they find, well, you know, this is a high, you know, sick population, right? So mortality of 17 percent at six hours, you know, and over 30 percent at the 28-day mark. So why are we studying this? Well, I mean, look at these statistics. So it's the most common preventable cause of pediatric death. Unfortunately, firearm-related injuries surpass now MVC injuries in 2020. You see the mortality data there. Note that hypotension and transfusion upon arrival has 60 percent mortality. And that probably, you know, if you think back to that first graph, you know, these are kids at Verde over probably 30 percent blood loss. If they're coagulopathic or have shock, they have three times the risk of death. If they're coagulopathic and have shock, they have four times the risk of death. So there's a need to do research. We need better recognition of hemorrhagic shock. We need to think about the pre-hospital point because death can occur quickly. We need to think about how we can improve our resuscitation strategies and think about hemostatic adjuncts. Finally, in this bit of physiology, so recent work, you know, primarily by Barbara Gaines and Christine Leeper out of Pittsburgh, as well as Brian Cotton's group in Houston and Dr. Moore's work, you know, this is kind of similar to sepsis, right? I mean, we have different phenotypes of what happens after trauma. So it's a dynamic and, you know, heterogeneous process. So even in the same kid, you may see a change in their fibrinolytic profile over time. So these three distinct phenotypes have been identified, at least in terms of fibrinolysis. So about a quarter of them are hyperfibrinolytic, as measured by their percent lysis at 30 minutes of above 3 percent. And those are patients who have potentially the highest mortality. So about 30 percent have just physiologic fibrinolysis. And then this newer entity called fibrinolytic shutdown has probably the higher prevalence and also higher mortality than the physiologic fibrinolysis. So this has implications when you think about potentially using antifibrinolytics, right? So if you're just looking at a kid, you know, you really have no idea where they are unless you're measuring it. So we met back in April of 2022 in Alabama there at Rob's invitation. We had—here's our committee members. So we had, you know, several of us from the pediatric critical care arena. We had Rob and a bunch of other surgeons. Since, I think, Rob was organizing, mostly, I think, surgeons outnumbered us. We did have some blood bankers, people from the lab, as well as ER physicians and anesthesia involved. So I will put this QR code up again at the end if you don't catch it now. But we used pretty much just the standard guideline process. You know, it's been described as—we've had tons of other guideline presentations here. So I won't belabor this. And then we use the typical wording that you'll see in some of the other guidelines that have been presented here as well. So moving to prehospital, we suggest against a permissive hypotension strategy and suggest resuscitation goals that optimize end organ perfusion and O2 delivery. So just as we, you know, resuscitate any type of shock, right, it's also reasonable to utilize prehospital transfusion of blood products. So this is a study on the next slide based on product availability and judgments. And in children with exsanguinating extremity hemorrhage, we recommend the use of commercially available tourniquets by individuals with training. And a shout out to the Stop the Bleed program that many of you are familiar with. So this recent study came out this past year by, again, Barbara Gaines and Christine Leeper. They did a propensity match trial of patients who received prehospital transfusion versus those who had ER transfusion. And they found a reduction in mortality for those who were transfused prehospital. In terms of resuscitation, we recommended to prioritize the utilization of blood products over crystalloid for resuscitation. And that's based off of a number of trials that have showed increased harm with increased crystalloids. We also suggested to target high plasma to RBC ratios to minimize plasma deficits. So you may have heard of ratios, but in terms of the concept of deficits, that's basically subtracting, you know, RBCs minus the amount of plasma that you're giving. So this matters more, especially in your smaller children. The more RBCs that you're giving, you know, relative to plasma, you're going to increase your plasma deficit. So it matters in terms of the volume that you're giving a child. So, you know, think about the increased risk of coagulopathy, you know, the greater that deficit is. Similarly, to also target high platelet to RBC ratios to minimize the platelet deficit that you're giving a child in resuscitation. And again, this is only applying to that life-threatening traumatic hemorrhage, so not all comers with trauma. And then also the use of whole blood is to be considered, and Phil will talk about that more in a minute. So in this study from the PLITE study of 712 children at 24 trauma centers, average age in this group was seven. In the initial resuscitation, getting at least one or more crystalloid boluses led to transfusion in over half of patients. And as you suspect, increased crystalloid boluses was associated with increased time in the hospital, increased blood products, and increased time on a ventilator. In terms of the optimal transfusion ratios in pediatric trauma, this study by Butler looking at the pediatric TQIP database of over 120,000 patients, 580 of them had received a massive transfusion as defined by 40 mLs per kilo of blood products. And it was a sick population, almost 20% mortality. Those who had a higher FFP to RBC ratio at 424 hours had a decreased risk of mortality at the 24-hour mark. There was no significant association in this study with platelet to RBC ratios and mortality. And there was a higher risk of DVTs in patients with a greater than 2 to 1 of FFP to RBC ratio. So if you're overdoing it and giving more than double the amount of plasma to RBCs, we did see an indication of harm in this study. Again, whole blood and TXA we'll hear about in a minute. In terms of viscoelastic monitoring in traumatically injured children with hemorrhagic shock, adjunctive viscoelastic monitoring, when available, is suggested. Again, this language is based off of really the paucity of literature that is out there for studying using TAG in children and resuscitation. So a few conclusions here. From the prehospital standpoint, avoid permissive hypotension. Consider prehospital transfusion of blood products if needed, and then employ tourniquets if you have them, especially for extenuating extremity hemorrhage. Prioritize the use of blood products over crystalloids. Target high plasma to RBC and higher platelet to RBC ratios, and consider the use of whole blood. Also to consider use of TXA, and if available, use viscoelastic monitoring to assess resuscitation goals. So on the left, you'll see the link to the guidelines that we published. And on the right is a good just summary of damage control resuscitation put out by several of the people you see here. And I'll pass this on to Phil.

pediatric traumatic hemorrhage

multi-center studies

blood products

resuscitation strategies

prehospital care