HBOC-201: A Viable Alternative to Blood Transfusion
Use of hemoglobin-based oxygen carrier-201 avoided need for blood transfusion in nearly 60% of patients.
Despite strategies to conserve use of packed red blood cells (PRBCs), experts predict that availability will not meet the increasing demand by an aging population. Hemoglobin-based oxygen carrier-201 (HBOC-201) is a bovine–hemoglobin-based blood substitute that is approved in South Africa for clinical use. In a randomized, single-blind, controlled, multinational study, researchers (some of whom were affiliated with the manufacturer) assessed whether administration of HBOC-201 eliminates the need for PRBC transfusion in adult patients undergoing orthopedic surgery.
Overall, 688 patients (mean age, 61) with hemoglobin concentrations <10.5>7 mL/kg within 2 hours, oliguria, and significant weakness or dizziness. Patients in the HBOC group received a loading dose of 65 g of hemoglobin infused in 500 mL (a volume considered equivalent to 1 unit of PRBCs); additional doses were administered for up to 6 days to a maximum of 325 g (2500 mL), after which need for additional oxygen-carrying capacity was met by transfusion of PRBCs.
Overall, 59% of patients in the HBOC group did not require PRBC transfusion. The HBOC group had significantly higher rates of adverse events (e.g., elevated blood pressure) than the PRBC group (8.5 vs. 5.9 per patient) and serious adverse events (e.g., cardiac events and strokes; 0.34 vs. 0.25 per patient). Findings of a safety analysis led the authors to conclude that risk for adverse events from HBOC was greatest in patients who were older than 80, had volume overload, and were undertreated.
Comment: HBOC-201 does not require crossmatching and can be stored at room temperature for as long as 3 years. In this study, its use eliminated the need for transfusion of allogeneic PRBCs in 59% of patients. Its safety profile was inferior to that of PRBC transfusion, including a greater incidence of acute coronary syndromes and strokes, which the authors partially attributed to age older than 80, volume overload, and undertreatment. Overall, the authors suggest that patients younger than 80 with moderate clinical need for transfusion can be managed with up to 10 units of HBOC-201, thereby preserving the stockpile of PRBCs for other patients.
John A. Marx, MD, FAAEM, FACEP
Published in Journal Watch Emergency Medicine August 1, 2008
Citation(s): Jahr JS et al. HBOC-201 as an alternative to blood transfusion: Efficacy and safety evaluation in a multicenter phase III trial in elective orthopedic surgery. J Trauma 2008 Jun; 64:1484.