title: Pyridoxylated polyhemoglobin as a red cell substitute for resuscitation of lethal hemorrhagic shock in conscious rats.
abstract: In our previous work, pyridoxylated polyhemoglobin (PP-PolyHB) was shown to have a P50 = 16-18 torr, and a half-life (T 1/2) of 20 hrs in the circulation of rats given a 75% isovolemic exchange transfusion. For the present study, a rapid and lethal hemorrhagic shock model has been specifically designed to assess the ability of PP-PolyHB to function as an emergency resuscitation fluid. Using 48 fully conscious rats with special chronic arterial and venous cannulations, shock was induced by bleeding 67% of total blood volume in less than 40 min; producing 100% mortality in nonresuscitated controls. Resuscitation was carried out using one of the following infusion fluids equivalent in volume to the bled volume: Ringer's solution, albumin solution, stroma-free Hb (SFHb), pyridoxylated SFHb (PP-SFHb), PP-PolyHb, and whole blood. Long-term (greater than 8 day) survival rate of rats (n = 12) resuscitated with PP-PolyHb was 75% compared to 83% for autologous whole blood. Survival following resuscitation with the other fluids was substantially lower. These results indicate that PP-PolyHb could effectively resuscitate lethal hemorrhagic shock in conscious rats, and provide long-term survival afterwards, even in the absence of any additional fluid maintenance.
mesh_terms: D000818:Animals; D001794:Blood Pressure; D001802:Blood Substitutes / Q000627:therapeutic use*; D003243:Consciousness; D004632:Emergency Medical Services; D005440:Fluid Therapy; D006454:Hemoglobins / Q000627:therapeutic use*; D008297:Male; D010100:Oxygen / Q000097:blood; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives* / Q000627:therapeutic use; D051381:Rats; D011919:Rats, Inbred Strains; D012771:Shock, Hemorrhagic / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors
chemical_list: D001802:Blood Substitutes; D006454:Hemoglobins; C030939:polyhemoglobin-pyridoxal-5-phosphate; D011732:Pyridoxal Phosphate; D010100:Oxygen