The "Diamond of Death" in Trauma - Hypocalcemia
Highlights
- The Role of Calcium in Trauma
Key takeaways:
(* Calcium is important in trauma because it helps to contract smooth muscle and communicate with the heart., * Calcium can also be important in the coagulation cascade, which is a set of processes that help to prevent blood from clotting.)
Transcript:
Speaker 1
But what they did was basically look through what's on PubMed, what's on Google Scholar about hypocalsemia, trauma, and hemorrhage. And they kind of go over and discuss like, what is calcium? What does it do in the body? And we know that it helps contract smooth muscle, it helps contract the cardiac myocytes and communicate like, Hey, there's an actual potential here, go ahead and give that cardiac squeeze. But there are also some parts that like I just kind of didn't remember from from from sort of the basic sciences, which is like the role in the coagulation cascade. So like, why why would it be so important in trauma? And one of the first things is calcium and trauma has nothing to do really with the calcium at all, but has to do with some of the other stuff that's going on. So in trauma patients who are the six, six ones, they're typically the ones who are bleeding. And in bleeding patients, we give them blood. And typically what we start with are packed red blood cells, and packed red blood cells are stored with an anticoagulant called citrate and citrate is metabolized by the liver. And oftentimes it's not a big deal because your liver can metabolize three grams of citrate every five, 10 minutes. And so one, one unit of packed red blood cells has 1.66 grams. (Time 0:03:25)
- The Role of Hypokalemia in the Diamond of Death
Key takeaways:
(* Citrate can accumulate in the blood of trauma patients, leading to iatrogenic hypokalemia., * Hypokalemia can play a role in coagulopathy at all points in the process of bleeding., * Calcium is important for platelet function and adhesion, and is critical for patients with hypokalemia.)
Transcript:
Speaker 1
And so the citrate accumulates and what happens when the citrate accumulates in the patient's blood is it binds to that free calcium in the blood. And so this is a problem because then you have a trauma patient who's bleeding, you're giving them something and you're causing an iatrogenic hypokalcemia, potentially based on that. So this is one of the issues of transfusing blood products is because they are stored with that and that anticoagulant citrate binds calcium in the patient's blood and can can cause them more hypokalcemia. Now let's talk about that diamond of death and the role that hypokalcemia can play at all of those points. So the first of all is one that I kind of didn't fully remember, which is the role that calcium plays in coagulopathy. So coagulopathy, we know that already baseline not great in bleeding patients for a variety of reasons. Maybe they're anticoagulant, they got something else and they need every bit of help they can forming those proper clots. Well calcium is critical for platelet function and adhesion. So in order for the platelet store, they are supposed to work and then adhere to the places where you want clots to be, you need calcium and if you have a patient who's hypokalcemia, well that's not good because then their platelets aren't going to be working quite as appropriately. (Time 0:05:08)
- The Role of Hypokalemia in the Diamond of Death
Key takeaways:
(* Hypokalemia can cause coagulopathy, which can lead to more bleeding., * Calcium is important for platelet function and adhesion, and hypokalemia can make these processes less effective.)
Transcript:
Speaker 1
So this is one of the issues of transfusing blood products is because they are stored with that and that anticoagulant citrate binds calcium in the patient's blood and can can cause them more hypokalcemia. Now let's talk about that diamond of death and the role that hypokalcemia can play at all of those points. So the first of all is one that I kind of didn't fully remember, which is the role that calcium plays in coagulopathy. So coagulopathy, we know that already baseline not great in bleeding patients for a variety of reasons. Maybe they're anticoagulant, they got something else and they need every bit of help they can forming those proper clots. Well calcium is critical for platelet function and adhesion. So in order for the platelet store, they are supposed to work and then adhere to the places where you want clots to be, you need calcium and if you have a patient who's hypokalcemia, well that's not good because then their platelets aren't going to be working quite as appropriately. Also it matters for some of the intrinsic factors because calcium is a binding point on those coagulation factors. These are the like the intrinsic function of factors 2, 7, 9, 10 and protein C and S in that coagulation cascade, which we may have forgotten. But basically you need enough calcium in order for your blood to clot the appropriate way. (Time 0:05:25)
- The Effect of Transfusion on Serum Calcium Levels in Trauma Patients
Key takeaways:
(* A lot of trauma patients are already hypokalemic before receiving blood, and their calcium levels don't seem to matter., * Prehospital transfusion studies have found that a decent number of patients are hypokalemic even before getting blood.)
Transcript:
Speaker 1
Is it just in those patients that were inducing hypokalcemia actrogenically on like the ones that are getting units of blood and multiple units of blood and have impaired hepatic function? This isn't totally the case. There have been some retrospective studies done. One was by Webster at all. And this is a retrospective study where they basically looked at trauma patients between 2013 and 2014 who got a unit of blood and they looked at unice calcium levels before they got the blood and then after the blood. And what they found is that there was a difference in pre-transfusion and post-transfusion calcium levels. So basically patients did become more hypokalcemic after transfusion. However, a lot of the patients, 55% or so, were already hypokalcemic on arrival. And then that jumped up to 89% were hypokalcemic after receiving any amount of blood. So this is pretty common in trauma patients who were transfusing. This has sort of been replicated in other studies that have gone back and looked. There are some pre-hospital transfusion studies that looked at similar things and found very similar results is that a decent number of patients are hypokalcemic even before getting blood. And the question is like, do we actually care about their calcium level? What are the patient-centered outcomes? (Time 0:08:24)