A review of transfusion- and trauma-induced hypocalcemia: Is it time to change the lethal triad to the lethal diamond?

The understanding of trauma management and damage control resuscitation is constantly changing as new research becomes available. While poor outcomes in hemorrhagic shock have traditionally been attributed to the "lethal triad" of hypothermia, coagulopathy, and acidosis, research has suggested that hypocalcemia may also play an integrated part in this interaction. Studies have shown a prevalence of hypocalcemia in trauma patients, as well as greater mortality associated with severe hypocalcemia in trauma. Given that whole blood is becoming the fluid of choice in resuscitation and that the citrate used to preserve blood products can worsen existing hypocalcemia, prompt management of hypocalcemia becomes even more of a concern. For these reasons, the authors of this paper suggest hypocalcemia in trauma patients may be of greater importance than originally believed and propose creating the "lethal diamond" of trauma comprised of hypocalcemia, acidosis, coagulopathy, and hypothermia. It is hoped that this increased focus on hypocalcemia in trauma can lead to research regarding early administration of calcium with the hopes of improving trauma patient outcomes.Level of Evidence: Therapeutic/care management Level IV. Study Type: Review article.