Oxygen-carrying macromolecules: therapeutic agents for the treatment of hypoxia.

A stabilized form of hemoglobin as oxygen-carrying macromolecules was developed. It had an approximately 90,000 dalton molecular weight, and its intravascular half-life was 36 h. Its molecular size was less than 0.1 microm. Its hemoglobin concentration was 6% and its P50 value was 24 mm Hg. Oxygen carried inside plasma performs differently than oxygen carried inside red cells. Less than 0.3 cc of oxygen in 100 ml of blood is available in the plasma while 14-19 ml of oxygen is carried inside the red cells. Thus, less than 5 cc of oxygen is available inside the plasma of the entire body. When a patient develops hypovolemic shock, the red cells are bypassed and are not perfused directly inside the tissues. However, the plasma should reach hypoxic tissues. Thus, infusion of oxygen-carrying macromolecules into the plasma should be therapeutically effective even when infusing less than 100 ml of stabilized hemoglobin solution under shock conditions. The basic physiology of oxygen-carrying macromolecules is described in detail, which is different from the physiology of oxygen-carrying red cells.