Lactic acidemia in baboons after transfusion of red blood cells with improved oxygen transport function and exposure to severe arterial hypoxemia.

Baboons were bled one-third of their blood volume and then transfused with an equivalent volume of compatible donor red blood cells with 160 per cent of normal 2,3-diphosphoglycerate (2,3-DPG) levels and improved capacity to release oxygen to tissue. The mixture of baboon donor-recipient red blood cells in the circulation had a 2,3-DPG level of 130 per cent of normal. After transfusion, the baboon's inspired oxygen was first lowered from 21 to 10 per cent to produce severe arterial hypoxemia with a PO2 tension of less than 40 mm Hg for two hours and then restored to 21 per cent. Lactic acidemia occurred when the alveolar oxygen tension was reduced so as to produce an arterial oxygen tension of less than 40 mm Hg, even though oxygen consumption was maintained. The data suggest that when red blood cells with normal or improved oxygen delivering capacity are transfused to patients, the alveolar oxygen tension should be sufficient to maintain an arterial oxygen tension of greater than 40 mm Hg.