Transfusion of autologous, hydroxyethyl starch-cryopreserved red blood cells.

UNLABELLED

In this prospective, randomized study, we investigated the safety and efficacy of the transfusion of hydroxyethyl starch (HES) cryopreserved red blood cells (RBC) compared with the transfusion of liquid-stored RBC in patients undergoing major orthopedic or urologic surgery. Thirty-six patients donated autologous blood 35 +/- 6 days before elective surgery. Only the first of 3.5 +/- 1.3 donated units of RBC was randomly assigned to be stored in the liquid state at 4 degrees C in phosphate/adenine/guanosine/glucose/saline-Mannitol or frozen below -130 degrees C by means of liquid nitrogen after the addition of HES (molecular weight 200,000 Dalton, degree of substitution 0.5, final concentration 11.5% wt/wt) as a cryoprotectant. After induction of anesthesia, patients donated 900 mL of autologous blood before they received one unit of liquid-stored RBC in Group 1. In Group 2, one unit of cryopreserved autologous RBC was transfused after removal of the cryoprotectant HES. In Group 3, patients received one unit of cryopreserved RBC without any manipulation after thawing. Patients in Groups 1 and 2 received additional 500 mL of 10% HES. Hemodynamic variables, arterial blood gases, plasma hemoglobin, and arterial lactate concentrations were measured after the induction of anesthesia, after hemodilution, and at 10-min intervals after transfusion of the respective RBC concentrate over a period of 40 min. Skeletal muscle tissue oxygen tension was measured in the quadriceps muscle using an automatically stepwise-driven oxygen partial pressure electrode. We found no differences among groups concerning demographics, arterial blood gas values, and lactate concentrations and observed no adverse reactions after transfusion of the conventionally stored or cryopreserved RBC. Hemodynamic variables did not differ among groups, with the exception of an increased mean arterial blood pressure after the transfusion of cryopreserved unwashed RBC. In all groups, the skeletal muscle tissue oxygen tension remained constant after hemodilution and increased after transfusion of either washed or unwashed cryopreserved RBC. Although the free plasma hemoglobin concentration remained constant after the transfusion of liquid-stored RBC (26 +/- 8 mg/dL), the plasma hemoglobin concentration increased twofold after the transfusion of cryopreserved washed RBC (60 +/- 12 mg/dL) and threefold after transfusion of cryopreserved unwashed RBC (98 +/- 20 mg/dL). The authors conclude that transfusion of one unit of RBC after cryopreservation with HES is safe and well tolerated by patients. Intravascular volume replacement and skeletal muscle oxygenation characteristics by erythrocytes did not differ between liquid-stored and cryopreserved RBC.

IMPLICATIONS

This study examined whether a colloid should be used to store blood. Our data suggest that the transfusion of one unit of red blood cells after cryopreservation with hydroxyethyl starch is safe and well tolerated by patients. The effects of intravascular volume replacement and skeletal muscle oxygenation provided by red blood cells after liquid storage or cryopreservation were not different.