Low iCa levels at admission were associated with increased mortality as well as an increased need for both multiple transfusions and massive transfusion. In fact, multivariable logistic regression analysis identified low iCa levels as an independent predictor of multiple transfusions. Admission iCa levels may facilitate the rapid identification of patients requiring massive transfusion, allowing for earlier preparation and administration of appropriate blood products.

Low iCa is associated with prehospital hypotension regardless of age, ISS, or sampling time and is a better predictor of mortality than base deficit. Since acidosis reduces calcium binding to serum protein and actually increases iCa, the association between base deficit and iCa in this study requires further investigation.