Human Polymerized Hemoglobin for the Treatment of Hemorrhagic Shock when Blood Is Unavailable: The USA Multicenter Trial

Background: Human polymerized hemoglobin (PolyHeme, Northfield Laboratories) is a universally compatible oxygen carrier developed to treat life-threatening anemia. This multicenter phase III trial was the first US study to assess survival of patients resuscitated with a hemoglobin-based oxygen carrier starting at the scene of injury. Study Design: Injured patients with a systolic blood pressure ≤ 90 mmHg were randomized to receive field resuscitation with PolyHeme or crystalloid. Study patients continued to receive up to 6 U of PolyHeme during the first 12 hours postinjury before receiving blood. Control patients received blood on arrival in the trauma center. This trial was conducted as a dual superiority/noninferiority primary end point. Results: Seven hundred fourteen patients were enrolled at 29 urban Level I trauma centers (79% men; mean age 37.1 years). Injury mechanism was blunt trauma in 48%, and median transport time was 26 minutes. There was no significant difference between day 30 mortality in the as-randomized (13.4% PolyHeme versus 9.6% control) or per-protocol (11.1% PolyHeme versus 9.3% control) cohorts. Allogeneic blood use was lower in the PolyHeme group (68% versus 50% in the first 12 hours). The incidence of multiple organ failure was similar (7.4% PolyHeme versus 5.5% control). Adverse events (93% versus 88%; p = 0.04) and serious adverse events (40% versus 35%; p = 0.12), as anticipated, were frequent in the PolyHeme and control groups, respectively. Although myocardial infarction was reported by the investigators more frequently in the PolyHeme group (3% PolyHeme versus 1% control), a blinded committee of experts reviewed records of all enrolled patients and found no discernable difference between groups. Conclusions: Patients resuscitated with PolyHeme, without stored blood for up to 6 U in 12 hours postinjury, had outcomes comparable with those for the standard of care. Although there were more adverse events in the PolyHeme group, the benefit-to-risk ratio of PolyHeme is favorable when blood is needed but not available.