When blood is not an option: factors affecting survival after the use of a hemoglobin-based oxygen carrier in 54 patients with life-threatening anemia.

BACKGROUND: In consenting Jehovah's Witness patients and others for whom blood is contraindicated or not available, hemoglobin-based oxygen carrier (HBOC)-201 may enable survival in acutely anemic patients while underlying conditions are treated.

METHODS: Survival factors were identified in a multicenter, unblinded series of severely anemic "compassionate use" patients receiving available standard treatment plus consultant-supported HBOC-201 administration by novice users. Predictors of outcome were sought and compared between survivors and nonsurvivors. A compound variable, hemoglobin-duration deficit product was used to describe the interactive clinical effects of severity and duration of anemia. Mortality,correlations between patient characteristics, and survival to hospital discharge were determined from patient records.

RESULTS: Fifty-four patients (median age 50 years) with life-threatening anemia (median hemoglobin concentration at time of request = 4 g/dL) received 60 to 300 g HBOC-201.Twenty-three patients (41.8%) were discharged. Intraoperative blood loss (45%), malignancy(18%), and acute hemolysis (13%) were the prevailing reasons for anemia. Time from onset of anemia (< or = 8 g/dL) to HBOC-201 infusion was shorter for survivors than nonsurvivors (3.2 vs 4.4 days, P = 0.027). Mean hemoglobin levels before HBOC-201 infusion in survivors and nonsurvivors were 4.5 and 3.8 g/dL, respectively (P = 0.120). No serious adverse event was attributed to HBOC-201. The hemoglobin-duration deficit product separated survivors from nonsurvivors. Cancer and renal disease were associated with nonsurvival.

CONCLUSION: Earlier, compared with later, administration by inexperienced users of HBOC-201 to patients with anemia was associated with improved chances of survival of acutely bleeding and hemolyzing patients. Survival was more likely if the duration and magnitude of low hemoglobin was minimized before treatment with HBOC-201.