In vitro effects of a novel hemoglobin-based oxygen carrier on routine chemistry, therapeutic drug, coagulation, hematology, and blood bank assays

Red blood cell (RBC) replacement solutions are being developed as alternatives to allogeneic RBC use in blood transfusions in the treatment of massive trauma, to achieve hemodynamic stability during elective surgery, and to increase oxygen-carrying capacity in anemia. Hemoglobin-based oxygen carrier (HBOC)-201 (Biopure Corp.) is a purified, sterile, isosmotic glutaraldehyde-polymerized bovine hemoglobin. Because this product is acellular, blood components containing this substance appear hemolyzed. This study reports on the interferences produced by the presence of HBOC-201 in a variety of clinical assays. This product was added in vitro at concentrations up to 60 g/L (6.0 g/dL) to normal human serum, plasma, or whole blood before testing for serum chemistries, coagulation profiles, and hematology and blood bank assays. In addition, a set of normal human sera containing HBOC-201 was supplemented with various therapeutic drugs and assayed for these agents. The results of these studies demonstrate that the presence of HBOC-201 in blood components does not result in significant analytical interference that would be of concern with many clinical assays at HBOC-201 concentrations encountered during routine clinical use of this RBC replacement solution in patients.

The effects of a blood-salvaging device on blood containing a hemoglobin-based oxygen carrier, HBOC-201

OBJECTIVES

Hemoglobin-based oxygen carriers will be used concurrently with intraoperative blood salvage. The effects of salvage and processing on blood containing one such solution (HBOC-201; Biopure Corp, Boston, MA) were studied.

DESIGN

Prospective, randomized.

SETTING

Laboratory.

INTERVENTIONS

Sixteen blood units from healthy volunteers had either HBOC (1,500 mg/dL; n = 10) or normal saline (equivalent volume; n = 6) added. All units were salvaged and processed using a blood salvage device. Samples were analyzed for the concentration and molecular weight distribution of plasma hemoglobin and red cell morphology presalvage (pre) and following processing and washing (post 1). Five of the HBOC units underwent a second 1,000 mL wash (post 2).

MEASUREMENTS AND MAIN RESULTS

Processing and washing decreased the concentration of plasma hemoglobin (mg/dL) in HBOC units (1311 +/- 265 pre to 27.8 +/- 19.6 post 1 to 6.5 +/- 2.19 post 2), but did not change the plasma hemoglobin concentration in saline units (2.05 +/- 1.27 pre v 3.18 +/- 0.79 post 1). Total plasma hemoglobin in HBOC units (6.56 +/- 2.19) was significantly greater than in saline units (3.18 +/- 0.79), even after the second wash (post 2). The concentration of unstable hemoglobin in the plasma phase was not different between groups. Red cell morphology was altered by the salvage process but was not different between groups.

CONCLUSIONS

Salvage and processing of blood containing HBOC yield concentrated red cells that are indistinguishable from those obtained from blood without HBOC. Residual HBOC remains but is unchanged from the HBOC initially administered.