Minimising changes in plasma calcium and magnesium concentrations during plasmapheresis

Admission hypocalcemia in pediatric major trauma patients-An uncommon phenomenon associated with an increased need for urgent blood transfusion

BACKGROUND

Hemorrhage is a leading cause of death among children. Recent data from adult trauma suggests that early, transfusion-unrelated, hypocalcemia is common and that it is associated with an increased need for blood transfusion, mortality, and coagulopathy. The objectives of this study are to evaluate the prevalence of admission hypocalcemia in severely injured children and its correlation with urgent blood transfusion.

STUDY DESIGN AND METHODS

This is a retrospective cohort study of all severely injured (Injury Severity Score [ISS] > 15) pediatric (<18 years) trauma patients admitted to Rambam Health Care Campus, Israel between 2012 and 2020. We excluded patients transferred from other facilities and those who received blood before determining calcium levels. Severe hypocalcemia was defined as ionized calcium (Ca⁺⁺ ) < 1.0 mmol/L and mild hypocalcemia as 1.0 mmol/L ≤ Ca⁺⁺  < 1.1 mmol/L. The primary outcome was urgent blood transfusion (transfusion in the emergency department [ED]).

RESULTS

Six hundred seventy-three severely injured children were admitted from the field. Ca⁺⁺ levels were determined before blood transfusion in 457 patients. Severe hypocalcemia was found in three patients (0.7%) and mild hypocalcemia in additional 21 patients (4.6%). Hypocalcemic patients required more urgent blood transfusion (29.2% vs. 6.5%, p < .001) and had higher ISS (29 [interquartile range, IQR: 22-35] vs. 25 [IQR: 19-34], p = .05). Multivariable logistic regression analysis identified Ca⁺⁺  < 1.1 mmol/L as an independent predictor of the need for blood transfusion, odds ratio 5.44 (95% confidence interval 1.44-20.58), p = .01.

DISCUSSION

Contrary to adults, admission hypocalcemia is uncommon in severely injured children. However, it may be associated with an increased risk of blood transfusion in the ED.

Transfusion-Related Hypocalcemia After Trauma

BACKGROUND

Hypocalcemia is cited as a complication of massive transfusion. However, this is not well studied as a primary outcome in trauma patients. Our primary outcome was to determine if transfusion of packed red blood cells (pRBC) was an independent predictor of severe hypocalcemia (ionized calcium ≤ 3.6 mg/dL).

METHODS

Retrospective, single-center study (01/2004-12/2014) including all trauma patients ≥ 18 yo presenting to the ED with an ionized calcium (iCa) level drawn. Variables extracted included demographics, interventions, outcomes, and iCa. Regression models identified independent risk factors for severe hypocalcemia (SH).

RESULTS

Seven thousand four hundred and thirty-one included subjects, 716 (9.8%) developed SH within 48 h of admission. Median age: 39 (Range: 18-102), systolic blood pressure: 131 (IQR: 114-150), median Glasgow Coma Scale (GCS): 15 (IQR: 10-15), Injury Severity Score (ISS): 14 (IQR: 9-24). SH patients were more likely to have depressed GCS (13 vs 15, p < 0.0001), hypotension (23.2% vs 5.1%, p < 0.0001) and tachycardia (57.0% vs 41.9%, p < 0.0001) compared to non-SH patients. They also had higher emergency operative rate (71.8% vs 29%, p < 0.0001) and higher blood administration prior to minimum iCa [pRBC: (8 vs 0, p < 0.0001), FFP: (4 vs 0, p < 0.0001), platelet: (1 vs 0, p < 0.0001)]. Multivariable analysis revealed penetrating mechanism (AOR: 1.706), increased ISS (AOR: 1.029), and higher pRBC (AOR: 1.343) or FFP administered (AOR: 1.097) were independent predictors of SH. SH was an independent predictor of mortality (AOR: 2.658). Regression analysis identified a significantly higher risk of SH at pRBC + FFP administration of 4 units (AOR: 18.706, AUC:. 897 (0.884-0.909).

CONCLUSION

Transfusion of pRBC is an independent predictor of SH and is associated with increased mortality. The predicted probability of SH increases as pRBC + FFP administration increases.