The Need for Aggressive Correction of Hypocalcemia During Traumatic Massive Transfusion Protocol

Introduction Hypocalcemia is a common side effect of massive transfusion protocols (MTPs) after traumatic injury. The relationship between hypocalcemia severity and transfusion volume has been investigated, but the physiologic impact is not well understood. The aim of this study was to investigate calcium levels in MTP patients, hypothesizing that patients with hypocalcemia would experience an increased risk of mortality. Methods A retrospective review of trauma patients undergoing MTP (≥10 units of blood within 24 hours) from 2018 to 2023 was conducted at a single institution. Ionized calcium (iCal) levels were collected on admission and after MTP. Calcium was administered with every four units of red blood cell products. Patients were stratified by 6- and 24-hour mortality. Logistic regression analysis was performed to assess for risk factors associated with mortality. Results 153 patients underwent MTP with 39 (26%) patients dying within 6 hours and 52 (34%) within 24 hours. The median admission iCal was 0.97 mmol/L and 1.23 mmol/L after MTP. A median of 4 g of calcium was given during MTP. Patients who died within 6 hours had a lower median post-MTP iCal (0.84 vs 1.27 mmol/L, P < 0.001) and higher total grams calcium given (6 vs 4 g, P = 0.026). Higher post-MTP iCal was associated with decreased odds of mortality (OR 0.013) and remained significant in a multivariable model (Table 1) with similar results for 24-hour mortality (Table 2). Conclusion Hypocalcemia after MTP is associated with increased 6- and 24- hour mortality. Aggressive and early correction may reduce mortality in MTP patients.