Effects of sodium o-iodobenzoate on acid-base parameters and survival in dogs with hemorrhagic shock.

Sodium o-iodobenzoate (OISB) produces an increase in P50 (PO2 at 50% of oxyhemoglobin saturation) and survival when infused at the time of initiation of prolonged hemorrhagic shock in dogs. Acid-base parameters improved during treatment, and plasma lactic acid concentrations showed smaller rises than in nontreated control animals. Erythrocyte 2,3-diphosphoglycerate (2,3-DPG) rose in prolonged hemorrhagic shock in the control group and conversely decreased in OISB-treated dogs. OISB did not require red cell integrity, since its effects were still more marked in hemolyzed blood. The therapeutic benefit of OISB, appears to be related to a direct effect of the agent on the hemoglobin molecule.