The expected PaO2 for an 80-year-old man who is otherwise in good health and breathing room air is approximately what level?
a. 50 mm Hg
b. 75 mm Hg
c. 80 mm Hg
d. 90 mm Hg
Q. 2 What is the most common cause of hypoxemia in patients with lung disease?
a. Diffusion defect
b. Hypoventilation
c. Right-to-left shunt
d. mismatch
Q. 3 In the presence of an acutely reduced arterial O2 content (hypoxemia), normal O2 delivery to the tissues can be maintained by which of the following?
a. Hyperventilation (increased VA)
b. Increased RBC production
c. Increasing the cardiac output
d. Peripheral vasoconstriction
Q. 4 Hypoxia is best defined as a condition in which what occurs?
a. Blood Hb levels are less than normal (15 g/dl).
b. The arterial PCO2 is greater than normal (45 mm Hg).
c. The arterial PO2 is greater than normal (100 mm Hg).
d. Tissue O2 delivery is inadequate to meet cellular needs.
Q. 5 Which of the following are potential causes of hypoxia? 1. Decrease in arterial PO2 2. Decrease in available Hb 3. Decrease in cardiac output
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
Q. 6 A patient breathing room air at sea level has the following arterial blood gases: PaO2 = 62 mm Hg; PCO2 = 75 mm Hg. When the FIO2 is raised to 0.28, the PaO2 rises to 95 mm Hg. What is the most likely cause of the hypoxemia?
a. Hypoventilation
b. Impaired diffusion
c. Right-to-left shunt
d. V/Q imbalance
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