Thanks, everybody. I know it's officially past 5 o'clock, so you are welcome to go whenever. But this is kind of where the rubber meets the road. There's a lot to talk about. I'm going to do my best. And this is going to be recognition and management, because you can't treat it if you can't find it. And I think that's going to be important here. I'm the medical director for the cardiovascular ICU and the ECMO program. These are my disclosures. I'm a consultant for an ECMO company called Levonovo, but that's not going to be pertinent here. I'm not going to talk about pregnant people. That's a different talk for a different time. Telling me about postoperative bleeding is kind of like saying, tell me about Europe. There's a lot to talk about. I'm going to do my best. So the incidence of postoperative bleeding, it depends, is really the short answer. So what surgery are you talking about, what literature you're looking at, what years you're searching, regions, and your definition of postoperative bleeding, which is always fun, as we alluded to earlier, that societal guidelines can't always agree on lots of things. And so these are some selected searches just to kind of give you a general idea. And abdominal surgery is what you're looking at as far as the risk of postoperative bleeding. Neurosurgery has got lots of different definitions. The overarching one is sufficient bleeding to warrant reoperation. Cardiac surgery, so aortic procedures bleed the most. Isolated cabbages tend to bleed the least. This is a slide looking at the impact as far as hospital days and length of stay. So bleeding complications are in black. Non-bleeding patients are in gray. And as you can see, it's significantly increases your overall length of stay if you have a bleeding complication postoperatively. Same study. They switched the colors, which is always fun. So now the bleeding patients are in gray, and the non-bleeding patients are in black. This is different surgical procedures and the bleeding complications and the cost. And as you can see, it is significantly more expensive to have a bleeding episode if you are in the hospital. This is everybody's favorite slide, so I just decided to show it one more time. But I think mine's the most fun, so I think I got that one going for me. So there's two different types of bleeding, I would argue, when we're talking from a practical perspective. I would say that there's macrovascular bleeding and there's microvascular bleeding. And we think of microvascular bleeding, or at least I do at least, as medical bleeding. And macrovascular bleeding is surgical bleeding. That's a simulation. I didn't actually put a picture of somebody who had their leg chopped off. So pathophysiology of medical bleeding or non-surgical bleeding. So there's a lot of factors that happen from surgery and then after surgery and then in critical illness in general that predispose patients to bleed. And so things like hypocalcemia, acidemia, dilution of their blood, coagulation factor deficiencies, hypothermia, lots of different things. We don't have to go through all of them. And then there are preoperative risk factors. So is someone on a DOAC? Does somebody have an inherited or an acquired clotting factor deficiency? Did they go on ECMO? Did they go on bypass? So lots of different things that predispose people. Ideally you know about this before they go into surgery, but it turns out our patients don't always tell us the truth all the time. And so pathophysiology of shock. So this is the oxygen delivery equation. Cardiac output times your content of arterial oxygen. So if we break that down, this is what it looks like. And so we all remember that oxygen delivery is kind of like a train. The hemoglobin is the boxcars and your cardiac output is the engine itself. And this is really important because I'm going to tell you some things that Dr. Miller's not going to like that he talked about earlier. So everybody pay attention to his reaction to some of these things. And if I take away the boxcars, regardless of what the engine is doing, the delivery drops, right? And so that's a really important thing to remember. And again, pathophysiology of shock, when your oxygen delivery starts to drop, anaerobic metabolism ensues, acidemia, vasoplegia, hypotension, SERS, cellular and organ dysfunction and ultimate shutdown, and then death. This is another pathophysiology slide. So this kind of takes a look at the oxygen delivery versus consumption curves. You may have seen this in sepsis. It's similar in all types of shock, right? So in early stages of shock on the right side of the slide, your oxygen or your metabolic consumption is equal to your supply and your delivery. And that's fine, right? That's good. As we move down to the left, it's the later stages of shock. We get to the point where if our delivery starts to drop in this part of the curve, right, our metabolic demand is starting to exceed our metabolic supply. And that becomes an issue, as we talked about earlier. You start to get organ dysfunction and ultimately cellular death. Your oxygen consumption does drop in late stages of shock, right, because your tissues are dead. And so they're not consuming oxygen anymore. So back to our different types of bleeding. So microvascular bleeding, I think of this as diffuse oozing. It's not very scientific, but it's just the way I describe it. Exudative hemorrhage is also cited in the literature. Think of coagulation factor deficiencies. Think of thrombocytopenia. Don't forget about calcium, right? It's an important cofactor in the clotting cascade. That doesn't exist, right, Dr. Lang? Sorry, it's about factor IV. He's correcting me. Thank you, guys. Hyperfibrinolysis. Think ECMO. Think cardiopulmonary bypass. Think trauma, right? This is important. Acidemia, hypothermia, uremia, pre-existing diatheses. Again, ideally, you would have known about that prior to somebody going to the operating room. Macrovascular bleeding, right? So I think of this as the disruption of the integrity of a vascular structure or an organ. Think wound dehiscence, a nicked vessel intraoperatively. CPR. So remember, you know, in post-operative cardiac surgery patients, for example, if their sternum is pressed on, right, we now would do CALS instead of traditional ACLS. But in some places, we do ACLS. They get chest compressions. If your sternum dehisces, you can actually lacerate the right atrium. You can lacerate the great vessels, right? Big deal, obviously. And then, of course, you can also And so other things. So splenic ruptures, right? So if you do CPR in the wrong place, you can actually fracture the spleen. You can fracture the liver. And this causes major bleeding. Again, macrovascular versus microvascular. This will be a theme in this because it's really important. You can't treat it if you don't know what to treat. I think of within the surgical field, right? So macrovascular bleeding, you should be thinking about in the operative field, meaning where the surgery took place versus microvascular bleeding, we tend to think of outside of the surgical field. Macrovascular bleeding, so if something's surgically bleeding, we need to get back in there and fix it. And I think of medical management for microvascular bleeding, right? All of these agents that we can give, these prothrombotic agents, nothing's going to stop the bleeding if somebody's lacerated an artery, for example, right? You need to surgically repair that. And this is where the relationship between the surgeon and the intensivist is so important, right? Because we have to closely, all the scrub fans out there, I know, hopefully. So this is really, really important, right? Because we have to keep these communication lines open. We have to talk about these things. The surgeon has to tell you what they saw while they were in surgery. And then you have to be able to talk to the surgeon about what you're seeing on the medical side. So subsets of surgeries. So I think of macrovascular bleeding as being able to take place in all surgical patients, right? Microvascular can as well. But microvascular bleeding, you particularly want to think about your trauma patients and you want to think about your cardiac surgery patients. That's not to say that other surgical patients can't have microvascular bleeding. But cardiopulmonary bypass and trauma wreaks havoc on the coagulation cascade, right? You deplete your fibrinogen, you have platelet consumption. There's lots of changes that happen that predispose folks to this microvascular bleeding phenomenon. When to call the surgeon. So again, I've not met a surgeon that wants to be called late on their postoperative patient that's bleeding. And so again, really important to keep that relationship with your surgeon so that you can talk to them. Just like a TSA in the airport, if you see something, say something. That doesn't necessarily mean that patient's going back to the operating room, but at least you've done your due diligence of recognizing the issue. So some definitions of postoperative bleeding. So this is cardiac surgery. The universal definition of perioperative bleeding and the European cabbage grading scale. So these are two different grading scales that tell you the severity of bleeding. They're great. They're really good for research purposes. I find them a little bit impractical when you're standing at the bedside because the way that they quantify how severe your bleeding is by how much you've already bled. And so that's kind of like devising your war strategy based on how many people died in the battle just now. And so I find it to be not helpful sort of immediately, but they are good for telling you who's going to die. So they have mortality prognostication, right? If you bleed more, you tend to die more. That's kind of keeping it simple here. And then in trauma, so trauma is a little bit more practical. So the TASH or the trauma associated severe hemorrhage score, this was based on a study of 17,000 patients with severe blunt force trauma. This was a European study. These markers are nice because many of them, with the exception of a couple of lab values, can be assessed in real time at the bedside, including your point of care ultrasound, right? And then this is nice because when they're patients that had a score greater than 16, 90% of them required a massive transfusion protocol because of the severity of their blood loss. All right, so let's talk about management. So this is the title of this overarching talk. It's horrifically simple, which is wonderful and scary at the same time. All bleeding stops eventually. So I thought I would leave you with a management strategy that is horrifically simple as well. So step one, recognize the patient's bleeding. Step two, find the bleeding. And step three, stop the bleeding. And that's not quite the end of the talk because I would imagine that if I did, that would be most people's reaction. And so for the recognizing of the bleeding, you look at a couple of things, right? So we tend to look at our lab values. Something has changed in the vitals. The patient clinically looks different. They are deteriorating in some way, shape, or form. Remember, this is postoperative bleeding. And so you may or may not see anything, right? We'll talk about more of that later. But in the cardiothoracic surgery population, you watch your chest tube outputs. Watch their oxygenation. These patients, especially cardiac and thoracic surgery, they get hemothoraces, right? So you'll see their oxygenation drop if they're pooling blood in their thoracic cavity. Abdominal patients, watch their abdominal drains, their JP output. Watch for their urine output. I would say that's a good marker of perfusion in general as long as they have good renal function to begin with. But abdominal compartment syndrome can cause compression of the ureters. And so you drop your urine output. Neurosurgical patients, you watch your neurologic exam, their intracranial drains, right? Watch their ICPs. And then all of these patients, if you are actively bleeding, you should see changes in hemodynamics at some point, although the body is really good at compensating for this, right? With increased cardiac output, mobilization of interstitial fluid, so forth and so on to try to reconstitute the intravascular space. And so you don't always see this right away. And then most societal guidelines will say that postoperatively, a hemoglobin of greater than 3 grams per deciliter drop is cause for concern. You should suspect that they have postoperative bleeding. So find the bleeding. We kind of talked about all these tests ad nauseum. I don't need to talk about them some more. But we do look at our labs to try to figure out if there is where the issue may be and if there is product repletion that needs to be done. There are some physical exam findings that we should keep an eye out for for other disease processes like DIC. And then in macrovascular bleeding, so when in doubt, examine the patient, right? That's always a good idea. So if somebody is having things like retroperitoneal bleeding, a wound dehiscence, for example, so is there surgical wound bleeding? Sometimes we have to image them, right? They're not always stable enough to go down for imaging. But intracranial bleeding, obviously very important. Non-contrasted CTs can tell you some good things. And then your angiography can be helpful as well if you're concerned about bleeding vessels. OK. So again, this is a little bit on the rudimentary side. But macrovascular bleeding, so again, if you can see the bleeding, try to hold some pressure. Topical agents, there are numerous of them. There's a large number of them. We're not going to talk about any of them. Surgical re-exploration and interventional radiology can be good options for you. And then microvascular bleeding, correct the issues that we've kind of already discussed, right? Procoagulants, so we've talked a little bit about these as reversal agents. I'm not going to spend a lot of time on these. They are expensive, and they have a lot of side effects when you are giving them for reasons outside of what they're intended to do. So TXA and amylcopriac acid, they can be helpful in postoperative cardiac surgery patients as well as trauma patients. There is literature because of hyperfibrinolysis to help prevent, to inhibit fibrinolysis. But the rest of your PCC, your prothrombin complex concentrates, you sort of give them very much at your own risk. The only time I've ever used these is in the setting of life-threatening medical bleeding, right? So there's not some operative issue that needs to be dealt with. I'm not saying that they were good options, but at the time, you're trying to save the patient that's sitting in front of you. Again, they are riddled with complications, so buyer beware. All right, Dr. Miller's going to love this one, so everybody watch the expressions. And so I'm going to tell you that I would agree that we need to be cautious with our blood product utilization. And I would also agree that in the euvolemic anemic patient, they do not necessarily need blood. And so I would caution everybody that there are times and contexts in which to give blood products. However, when someone is actively bleeding, and they are losing large volumes of whole blood, and they are losing boxcars, and you are losing oxygen delivery, sometimes you need to give them back what they lost. And I know that that's an oversimplification, but the things to remember is that we need to deliver oxygen to the tissue we need to restore some circulating volume, which again, you can do with your crystalloid products. However, things to remember with crystalloid products is that they have no oxygen delivering capacity. And so you can restore circulating volume, but now you are relying purely on your cardiac output. And so there is literature and high altitude mountaineers, right, that their oxygen levels can drop down to saturations of 30, 40%. But their lactate levels are normal. And the reason their lactate levels are normal is because their hemoglobin is 15. That's their blood. That's not someone else's blood. And it's important that we all recognize that. But the idea being that if somebody is actively bleeding, we need to restore oxygen delivery while we're trying to figure out why. There's also a concept of dilutional coagulopathy, where giving large volumes of crystalloid can cause issues with your clotting cascade. All right, so massive transfusion protocols. Again, we're not going to talk about this in depth. They exist. Your institution has one. The structure on the left is a level one transfuser. It can give large volumes of blood at large speeds. It can also warm the product. Remember, so hypothermia is a major reason why people continue to bleed. And so we don't want to give people cold blood if we're giving lots of it. So these are from the British Journal of Anesthesia. So this is non-cardiac surgical patients. These are perioperative bleeding recommendations. We use them in the ICU for people who are actively bleeding. But just sort of keep some of these things in mind. They are goal-directed, which is another important statement to mention. We're not just randomly giving product. When it comes to transfusion thresholds, so I think the hemorrhagic shock population trauma literature is really good. And they've really done great work there. The cardiac surgery literature, I think, is also quite good from the non-hemorrhagic side. And so the TRAX trials and the TRICS trials, not the TRIC, not T-R-I-C-C, but T-R-I-C-S, transfusion and cardiac surgery, looked at liberal versus conservative strategies. There was no difference in mortality. Conservative strategies being hematocrits of 24 to 25, liberal being hematocrits to 28 and 30. There was obviously increased blood product utilization and greater cost, as well as increased blood product transfusion-related adverse events in the liberal transfusion group. So just some take-home points. So again, macrovascular bleeding, you need to rule that out early. You need to treat hemorrhagic shock early and aggressive with goal-directed therapy. Don't just blindly give product. Early discussions with the surgeons. Use your point-of-care ultrasound so that you don't have to transport patients. All post-operative patients are at risk for both of these. That should probably be a cross here. But your trauma and cardiac surgery patients, you should think of microvascular bleeding earlier, I would say. Think of bleeding within the surgical bed versus bleeding outside of the surgical bed. Don't forget to use your physical exams. And then communicate, communicate, communicate. That's it. Thanks.

postoperative bleeding

microvascular bleeding

cardiovascular ICU

massive transfusion protocols

coagulation cascade