Aggressive calcium chloride dosing reduces early mortality in trauma patients receiving whole blood resuscitation.

BACKGROUND

Hypocalcemia has been recognized as a contributor to trauma-related mortality, yet optimal dosing of calcium during massive transfusion remains undefined. The literature suggests that ≥1 g of calcium per 2 to 4 units of blood may correct hypocalcemia, but its effect on survival is unclear. This study evaluated the association between varying calcium:low-titer O whole blood (LTOWB) ratios and 24-hour mortality to define clinically meaningful supplementation targets.

METHODS

We performed a retrospective single-center cohort study of all trauma patients receiving LTOWB and calcium, prehospital, or within 4 hours of arrival (2020-2023). Demographics, mechanism of injury, Injury Severity Score (ISS), transfusion volume, and calcium administration were collected. Calcium supplementation was defined as a continuous variable (grams/unit), mutually exclusive ranges, and threshold doses of ≥1 g per 2, 3, or 4 units of LTOWB. The primary outcome was 24-hour mortality. Multivariable logistic regression adjusted for confounders and calcium supplementation strategy.

RESULTS

Of 542 LTOWB recipients, 99 undergoing CPR were excluded; 164 received no calcium, and 273 had complete datasets for analysis. Median age was 36 (25-50) years, 72% were male, median ISS was 19 [10-28], and 55% sustained blunt trauma. Median arrival ionized calcium was 1.02 (0.79-1.14) mEq/L. Twenty-four-hour mortality was 13.6% (n=37). On multivariable analysis, ≥1 g calcium chloride per 2 units of LTOWB independently reduced the odds of 24-hour mortality by 84% [odds ratio, 0.164 (0.034-0.796), p =0.025]. Calcium chloride at this threshold neared significance for reduction in mortality ( p =0.06, adjusted OR=0.221 (0.045-1.077)] when restricting the analysis to patients receiving ≥2 units of LTOWB, while gluconate had no significant associations in this cohort with greater need for LTOWB resuscitation.

CONCLUSIONS

In trauma patients receiving LTOWB, calcium chloride administered at ≥1 g per 2 units showed a consistent association with improved early survival. A ≥1:2 calcium chloride-to-LTOWB dosing protocol may be an effective and clinically relevant target for trauma resuscitation. Prospective validation is warranted. ( J Trauma Acute Care Surg. 2026;101: 57-64. Copyright © 2026 Wolters Kluwer Health, Inc. All rights reserved.).

LEVEL OF EVIDENCE: Retrospective cohort study; Level III.