Purpose: To determine free hemoglobin concentration in patients who received massive blood transfusion during emergency surgery for trauma with consideration of the storage of the transfused blood.

Methods: Fifteen patients undergoing emergency surgery for multiple trauma and who received blood transfusion of more than 5,000 mL were studied. Transfusion of the stored whole blood in citrate-phosphate glucose solution using a micropore filter was started before surgery. Serum concentrations of hemoglobin (total: THb and free:fHb) and total haptoglobin (THp) were measured until 5,000 mL of blood had been transfused. Serum free haptoglobin (fHp) concentration was calculated. The correlation between the changes in hemoglobin or haptoglobin concentrations and total storage days of the transfused blood was analyzed by a simple regression analysis.

Results: Free hemoglobin was detected after 2,000 mL transfusion. The THp and fHp decreased after 1,000 mL transfusion. Total storage time (days) of transfused blood had correlated with the changes of THp (P<0.0001) and fHp (P=0.0027) but not with the changes of THb (P=0.984) and fHb (P=0.834).

Conclusion: After blood transfusion during surgery for trauma, serum haptoglobin concentration decreased with transfusion of ≥1,000 mL of whole blood with mean storage time of 12.2 dy. Free hemoglobin was detected after 2,000 mL transfusion when THp decreased to 1,000 mg·L⁻¹. Serum haptoglobin concentrations correlated negatively with storage time (days) of transfused blood.