Initial Ionized Calcium Derangements on ED Arrival After Major Trauma

In a prospective, multicenter trauma cohort, investigators reported that arrival ionized calcium derangements were frequently present at emergency department presentation after major injury and that mortality varied across calcium strata in a U-shaped pattern. Ionized calcium was measured immediately upon arrival to the ED. By grouping patients by arrival calcium category, the investigators compared presentation characteristics, resuscitation exposures, and short-interval mortality. The report focuses on how a single ED-arrival biomarker aligned with early outcome gradients in major trauma.

The cohort enrolled patients meeting the highest level of trauma activation criteria across three American College of Surgeons–verified level I trauma centers from 2022 to 2024; 1,270 participants had an arrival ionized calcium (iCa) value available and were included. iCa (rather than total serum calcium) was obtained immediately upon ED arrival, and a study-wide 4.4–5.2 mg/dL reference range was used to define hypocalcemia, eucalcemia, and hypercalcemia. Using that categorization, 22% of patients were hypocalcemic on arrival, 73% were eucalcemic, and 5% were hypercalcemic. The authors reported that trauma laboratory order sets were modified to include iCa and that testing reflected the equipment available at each institution. These definitions and standardized groupings supported cross-sectional comparisons at presentation and through early outcomes.

Early mortality was reported as stratified by arrival iCa categories, with a U-shaped distribution across groups. For 24-hour mortality, deaths occurred in 11.9% of patients with hypocalcemia, 4.3% with eucalcemia, and 22.8% with hypercalcemia. Mortality was also presented at other time points (including earlier and later follow-up), with differences described as remaining higher in both derangement groups than in the eucalcemic group. Across these analyses, mortality separation was framed as an association between the initial iCa strata and subsequent survival outcomes.

Resuscitation exposures in the first 24 hours were summarized by arrival calcium category. Any blood product administration within 24 hours was more frequent among patients with hypocalcemia and hypercalcemia than among those with eucalcemia (64.1% and 66.7% vs 31.5%, respectively). Beyond this binary comparison, the investigators reported greater 24-hour blood product consumption in both hypocalcemia and hypercalcemia compared with eucalcemia, while noting similar consumption when comparing hypocalcemia with hypercalcemia. In this cohort, transfusion exposure was presented as another parameter that tracked with the arrival iCa categories.

Supplemental reporting described prearrival contrasts that paralleled the in-hospital comparisons. Patients categorized as hypercalcemic were more likely than hypocalcemic patients to have received prehospital calcium (14.0% vs 1.4%), and the incidence of hypocalcemia was described as higher among those who received prehospital blood or intravenous fluids. In the discussion, the authors emphasized the observational nature of the findings and noted that prospective interventional trials would be needed to clarify the implications of empiric calcium administration during resuscitation. They positioned the results as descriptive associations intended to motivate additional study rather than evidence for causation.

Key Takeaways:

• Arrival ionized calcium abnormalities were common in this multicenter major trauma cohort, with hypocalcemia occurring more often than hypercalcemia.
• Early mortality showed a U-shaped pattern across arrival calcium categories, with higher mortality reported in both derangement groups than in the eucalcemic group.
• Calcium derangements on arrival were reported alongside higher early transfusion exposure, and the authors noted that prospective interventional trials are needed to clarify the implications of empiric calcium treatment.