title: Changes in blood P50. Effects on oxygen delivery when arterial hypoxemia is due to shunting.
abstract: The theoretic effect of increased values for the oxygen pressure at an oxygen saturation of 50 percent on oxygen delivery in arterial hypoxemia due to right-to-left shunting was analyzed using a mathematical model of the oxygen-hemoglobin equilibrium curve. We found that, regardless of the size of the shunt, a rightward shift of the curve resulted in increased mixed venous oxygen tension, increased arterial oxygen pressure, and, hence, a decreased alveolar-arterial oxygen pressure difference compared to the standard curve (hemoglobin level, cardiac output, and oxygen consumption remaining constant).
mesh_terms: D001158:Arteries; D002245:Carbon Dioxide / Q000097:blood; D002302:Cardiac Output; D006330:Heart Defects, Congenital / Q000150:complications*; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D000860:Hypoxia / Q000097:blood* / Q000209:etiology; D008954:Models, Biological; D010100:Oxygen / Q000097:blood*; D014680:Veins
chemical_list: D006454:Hemoglobins; D002245:Carbon Dioxide; D010100:Oxygen