Hemoglobin and methemoglobin concentrations after large-dose infusions of diaspirin cross-linked hemoglobin

Diaspirin cross-linked hemoglobin (DCLHb) solution is a purified human hemo globin product chemically stabilized to deliver oxygen to tissues. We deter mined the peak plasma hemoglobin concentration and assessed changes in meth emoglobin concentration after the infusion of 1 g/kg DCLHb in large blood l oss surgical patients. This prospective, randomized study included 26 surgi cal patients who were either infused with up to three 250-mL units of 10% D CLHb or transfused with up to three units of packed red blood cells during the study infusion period. Serial plasma hemoglobin, plasma methemoglobin, and whole blood methemoglobin levels were measured before and at intervals up to 48 h after the study infusion period. Plasma hemoglobin and blood met hemoglobin concentrations increased during the infusion of DCLHb. The plasm a hemoglobin values in the DCLHb group continued to increase during each of the infusion periods to reach a peak plasma concentration of 1450 +/- 176 mg/dL. The fraction of whole blood methemoglobin increased from 0.84 +/- 0. 77% at baseline to 4.08 +/- 1.36%. With a median DCLHb dose of 936 mg/kg (r ange 658-1500 mg/kg), the harmonic mean half-life was 10 h, and the increas ed whole blood methemoglobin reached a range not associated with complicati ons.