Empiric Calcium in Massive Transfusion

Advancements in the area of transfusion and blood product administration have occurred with the use of viscoelastic assays and whole blood. However, as we resuscitate trauma patients with blood products, hypocalcemia is an inadvertent side-effect. Citrate within stored blood binds calcium, causing patients to have hypocalcemia. In addition, outside of transfusion related hypocalcemia there is an independent trauma/inflammation related mechanism for hypocalcemia in the trauma patient. Furthermore, Calcium is a critical component of the coagulation cascade, and therefore a highly important component of hemostatic resuscitation. Hall et al found that patients receiving 13 or more units of PRBCs had a much higher prevalence of severe hypocalcemia and at least one ionized calcium \<1.0mmol/L. Kronstedt el al reported an association between hypocalcemia and mortality in trauma patients receiving massive transfusion. Despite evidence that hypocalcemia occurs with transfusion, and evidence that hypocalcemia in patients with hemorrhagic shock may be associated with increased mortality, there are no randomized controlled trials evaluating the administration of calcium in trauma resuscitation. Currently, the Joint Trauma System revised guidelines for damage control resuscitation from 2019 recommend administering 1g of calcium after the first unit of blood transfusion, and an additional 1g after no more than 4 units of blood administration. However, these recommendations are based on small cohort studies or retrospective studies. The purpose of this study is to evaluate the efficacy of early empiric intravenous calcium administration on transfusion requirements, vasopressor use and mortality in hemorrhaging trauma patients with initiation of a massive transfusion. All trauma patients in which massive transfusion is initiated within 6 hours of arrival will be enrolled. Two study arms will be created, one will receive 2g IV calcium with the initial transfusion and the other will only receive calcium supplementation based on routine ionized calcium levels and/or physician discretion. All critical trauma activations will get a baseline ionized calcium as part of their initial labs.