Mechanisms of hypoxemia and hypercapnia in the perioperative period

There are numerous mechanisms of hypoxemia and hypercapnia during the perioperative period. Mechanisms of hypoxemia include oxygen delivery problems, decreased FAC-CC relationship, hypoventilation, decreased cardiac output, increased oxygen consumption, decreased hypoxic pulmonary vasoconstriction, and increased nonalveolar right-to-left shunting. Mechanisms of hypocapnia include increased carbon dioxide production, increased alveolar dead space, and increased external dead spaces. Pulmonary diseases often involve multiple mechanisms to produce hypoxemia and hypercapnia.