Massive Transfusion Increases Serum Magnesium Concentration

Abstract

(1) Background: The massive transfusion of packed red blood cells (RBCs) is a lifesaving procedure, but it is associated with complications, e.g., dysmagnesemia. Since magnesium is an intracellular ion, the transfused RBCs can significantly influence the magnesium concentration in the recipient's blood. (2) Methods: A retrospective study was performed among 49 patients hospitalized in the Central Clinical Hospital of the Medical University of Warsaw who received a massive blood transfusion (≥4 units/h). Data on laboratory results and patient history were collected from the hospital database. The intracellular RBCs magnesium concentration was measured in 231 samples using the colorimetric method. (3) Results: There were statistically significant changes in the mean serum magnesium concentration preoperatively and 24 h postoperatively (0.87 ± 0.13 vs. 1.03 ± 0.14, p < 0.00001) and 48 h postoperatively (0.87 ± 0.13 vs. 1.06 ± 0.15, p < 0.00001). Patients who died had significantly higher serum magnesium concentrations (p < 0.05). The median intracellular magnesium concentration in RBCs was 0.91 (0.55-1.8) mmol/L, which is below the reference values of 1.65-2.65 mmol/L. (4) Conclusions: Transfused RBCs significantly increased the serum magnesium concentration 24 h and 48 h postoperatively. It could be a result of mild hemolysis, as the median intracellular magnesium concentration in RBCs was below the reference values.

Keywords: RBC; hypomagnesemia; magnesium; transfusion.

Figure 1

(A) The difference in the total serum magnesium concentration between preoperative and 24 h postoperative values (p < 0.00001). (B) The difference in the total serum magnesium concentration between preoperative and 48 h postoperative values (p < 0.00001).

Figure 2

Differences in the hypermagnesemia incidence before the massive transfusion and 24 h and 48 h postoperatively.

Figure 3

(A) Mean serum magnesium concentration depending on the outcome 24 h and 48 h postoperatively (p < 0.05). (B) The difference in hypermagnesemia prevalence between patients who died and survived 24 h postoperatively (p < 0.05). (C) The difference in hypermagnesemia prevalence between patients who died and survived 48 h postoperatively (p < 0.05).