Impact of hypocalcemia on mortality in pediatric trauma patients who require transfusion

BACKGROUND Admission hypocalcemia has been associated with poor outcomes in injured adults. The impact of hypocalcemia on mortality has not been widely studied in pediatric trauma. METHODS A pediatric trauma center database was queried retrospectively (2013–2022) for children younger than 18 years who received blood transfusion within 24 hours of injury and had ionized calcium (iCal) level on admission. Children who received massive transfusion (>40 mL/kg) prior to hospital arrival or calcium prior to laboratory testing were excluded. Hypocalcemia was defined by the laboratory lower limit (iCal <1.00). Main outcomes were in-hospital mortality and 24-hour blood product requirements. Logistic regression analysis was performed to adjust for Injury Severity Score (ISS), admission shock index, Glasgow Coma Scale (GCS) score, and weight-adjusted total transfusion volume. RESULTS In total, 331 children with median (IQR) age of 7 years (2–3 years) and median (IQR) ISS 25 (14–33) were included, 32 (10%) of whom were hypocalcemic on arrival to the hospital. The hypocalcemic cohort had higher ISS (median (IQR) 30(24–36) vs. 22 (13–30)) and lower admission GCS score (median (IQR) 3 (3–12) vs. 8 (3–15)). Age, sex, race, and mechanism were not significantly different between groups. On univariate analysis, hypocalcemia was associated with increased in-hospital (56% vs. 18%; p < 0.001) and 24-hour (28% vs. 5%; p < 0.001) mortality. Children who were hypocalcemic received a median (IQR) of 22 mL/kg (7–38) more in total weight-adjusted 24-hour blood product transfusion following admission compared to the normocalcemic cohort ( p = 0.005). After adjusting for ISS, shock index, GCS score, and total transfusion volume, hypocalcemia remained independently associated with increased 24-hour (odds ratio, 4.93; 95% confidence interval, 1.77–13.77; p = 0.002) and in-hospital mortality (odds ratio, 3.41; 95% confidence interval, 1.22–9.51; p = 0.019). CONCLUSION Hypocalcemia is independently associated with mortality and receipt of greater weight-adjusted volumes of blood product transfusion after injury in children. The benefit of timely calcium administration in pediatric trauma needs further exploration. LEVEL OF EVIDENCE Prognostic and Epidemiological; Level III.