Efficacy of Resuscitative Infusion with Hemoglobin Vesicles in Rabbits with Massive Obstetric Hemorrhage.
Hemoglobin vesicles have been developed as artificial oxygen carriers, and they have the potential to serve as a substitute for red blood cell transfusion.To evaluate the efficacy of hemoglobin vesicle infusion for initial treatment instead of red blood cell transfusion in rabbits with massive obstetric hemorrhage.Pregnant New Zealand white rabbits (28th day of pregnancy; normal gestation period 29-35 days) underwent uncontrolled hemorrhage to induce shock by transecting the right mid-artery and concomitant vein in the myometrium. Subsequently, rabbits received isovolemic fluid resuscitation through the femoral vein with an equivalent volume of hemorrhage every 5 min. Resuscitative infusion regimens included 5% human serum albumin (n=6), stored washed red blood cells with plasma (vol/vol = 1:1, n=5), and hemoglobin vesicle with 5% human serum albumin (vol/vol = 4:1, n=5). Sixty minutes after the start of bleeding, rabbits received surgical hemostasis by ligation of the bleeding vessels and then were monitored for survival until 24 h.During fluid resuscitation, hemoglobin vesicle infusion as well as red blood cell transfusion maintained mean arterial pressure > 50 mmHg, Hb concentration > 9 g/dL, and prevented the elevation of plasma lactate. In contrast, resuscitation with 5% human serum albumin alone could not prevent hemorrhagic shock as evidenced by a low mean arterial pressure (40 mmHg), low Hb concentration (2 g/dL), and a marked elevation of plasma lactate. All animals in the red blood cell group and the hemoglobin vesicle group survived more than 8 h, whereas all animals in the 5% human serum albumin group died within 8 h.HbV infusion may be effective in the initial management of massive obstetric hemorrhage.