A patient is admitted to the hospital because of hypoxemia.While the patient breathes ambient air,the arterial partial pressure of oxygen (Pao₂)is 50 mm Hg with an oxygen saturation of 82%.When the patient breathes 100% oxygen through a non-rebreathing mask,the Pao₂ is 83 mm Hg with an oxygen saturation of 92%.The cause of this patient's hypoxemia is probably:

Question

Quizplus · Accepted Answer

A physiological shunt is indicated by the patient's poor response to oxygen therapy, as seen by the relatively low increase in PaO2 despite breathing 100% oxygen. This suggests a portion of the blood bypasses the lungs without gas exchange.

A Patient Is Admitted to the Hospital Because of Hypoxemia