A 49-year-old man has a pulmonary embolism that completely blocks blood flow to his left lung. As a result, which of the following will occur?
Alveolar PO2 in the left lung will equal the PO2 in inspired air-No blood flow to the left lung- No gas exchange between the alveolar air and the pulmonary capillary blood-Consequently, O2 is not added to the capillary blood. The ventilation/perfusion (V/Q) ratio in the left lung will be infinite (not zero or lower than that in the normal right lung) because Q (the denominator) is zero. Systemic aerial PO2 will, of course, be decreased because the left lung has no gas exchange. Alveolar PO2 in the right lung is unaffected.
Ventilation/perfusion (V/Q) ratio in the left lung will be zero
Systemic aerial PO2 will be elevated
V/Q ratio in the left lung will be lower than in the right lung
Alveolar PO2 in the left lung will be approximately equal to the PO2 in inspired air
Respiratory System Pa 1