Is there a role for blood substitutes in civilian medicine: a drug for emergency shock cases?
The oxygen carried inside plasma performs differently than the oxygen carried inside red cells. Only 0.13-0.3 mL of oxygen in 100 mL of blood is available inside plasma while 14-19 mL of oxygen is carried inside red cells. Thus, less than 5-8 mL of oxygen is available in the plasma of the entire body. When a patient develops hypovolemic shock, red cells are bypassed and are not perfused directly inside the tissues. However, plasma should reach such hypoxic tissues. Thus, an infusion of oxygen-carrying macromolecules in plasma with a hemoglobin concentration of only 6% and P50 value of 24 mm Hg should be therapeutically effective even if less than 100 mL of stabilized hemoglobin solution (conjugated hemoglobin of 90,000 Da with a molecular size of less than 10 nm or 0.01 microm) are infused under shock conditions. The basic physiology of oxygen-carrying macromolecules is described in detail, which is different from the oxygen carried inside the red cells and inside encapsulated oxygen-carrying particles (typically 250 nm or 0.25 microm). Thus, the oxygen-carrying macromolecues are extremely effective in the treatment of shock patients. In emergency cases, after the bleeding is controlled, a small infusion volume of oxygen-carrying macromolecules will supply sufficient oxygen to the hypoxic tissues and immediately improve the blood pressure of shock patients.
Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA. ynose@bcm.tmc.edu
Yukihiko
Y
Nosé
D001802:Blood Substitutes / Q000494:pharmacology / Q000627:therapeutic use*; D001803:Blood Transfusion; D004638:Emergency Treatment / Q000379:methods*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D010100:Oxygen / Q000378:metabolism* / Q000627:therapeutic use; D012769:Shock / Q000503:physiopathology* / Q000628:therapy*
D001802:Blood Substitutes; D006454:Hemoglobins; D010100:Oxygen