Transfusing a lot of blood presents a lot of problems (not the least of which being that the patient needs a lot of blood to begin with!). Chief among those is likely the coagulopathy that results from a depletion of coagulation factors due to losing whole blood (PRBCs, plasma, and platelets) but only getting PRBCs back. Massive transfusion protocols (MTP) helps to address this by transfusing additional products in some sort of “proper” ratio (what that ratio IS is up for debate), but even if you transfuse PRBCs, FFP, and platelets in proper balance, you can still run into another life threatening complication. And I’m not talking about TACO (although that certainly is a problem). It’s one that may not be as readily recognized or remembered, but one that can wreak havoc with your resuscitation. Hypocalcemia.
Banked blood contains citrate as a preservative for storage. Citrate binds calcium and renders it inactive. Giving lots of banked blood can result in hypocalcemia. Hypocalcemia can cause all sorts of problems including hypotension (probably ALREADY a problem in someone requiring MTP) and seizures.
Pharmbythegram has a really nice post summarizing the role of calcium administration during MTP. Hopefully, you’ll now always remember to give calcium along with PRBCs, FFP, and platelets.
critical care notes 