Early Hypercalcemia Is Associated With Mortality in Critically Ill, Transfused Trauma Patients.

INTRODUCTION: The detrimental effects of calcium derangements are well recognized in trauma patients, especially in those requiring resuscitation. Although hypocalcemia has been associated with worse outcomes, hypercalcemia incidence and impact are unknown. We hypothesized that hypercalcemia is associated with higher mortality in trauma patients requiring blood transfusion. METHODS: Adult trauma patients who received blood products in the first 24 h at a level 1 trauma center from 2021 to 2022 and were evaluated. The institution's trauma registry and charts were reviewed to collect demographics, calcium levels, transfusion records, and outcomes. Youden indices were used to define extreme hypercalcemia. Multivariable logistic regression was performed to determine independent associations. RESULTS: Ninety-seven transfused trauma patients were included, 24 of whom received more than 4 units in 4 h. Free calcium of 7.99 had the highest Youden index for mortality and was used to define the lower limit of the extreme hypercalcemia cohort. The hypercalcemic and extreme hypercalcemia cohorts had comparable admission free calcium levels to the nonhypercalcemic cohort (4.6, 4.6, 4.7 mg/dL, P = 0.06). However, the hypercalcemic and extreme hypercalcemia cohorts had more calcium chloride administered (0, 1, 2 g, P = 0.001) and a higher number of units of blood transfused by 4 and 24 h (16 [5-93.5] versus 4 [2-8] units, P = 0.02). On univariable analysis, 30-d mortality was associated with extreme hypercalcemia, higher Injury Severity Score, and increased blood administration. On multivariable analysis, 30-d mortality remained associated with hypercalcemia (odds ratio, 17.5, confidence interval, 2.5-123.3; Wald P value 0.004) and platelets administered after 4 h (odds ratio, 2.3, confidence interval, 1.0-5.2; Wald P value 0.04). CONCLUSIONS: In this retrospective analysis of transfused trauma patients, extreme hypercalcemia was independently associated with 30-d mortality. Future studies should evaluate the physiologic impact of postinjury hypercalcemia.