Flashcards in Small Group 2 Gas Diffusion Deck (7):
How do you calculate the A-a gradient?
1. Calculate the pressure of inspired O2
2. Use PIO2 along with PACO2 and PaO2 to calculate A-a gradient
What is the cause of hypoxemia most commonly in the case of lung fibrosis?
V/Q mismatch due to destruction of both capillaries and alveoli
High ventilation rates can compensate for low V/Q ratio units for _____ but not _______
CO2 but not O2
How does alkalosis cause the oxyhemoglobin curve to shift?
to the left (greater Hgb-O2 affinity which is good for pick up but does not help for off-loading in the tissues)
What's a good rule of thumb that helps to estimate the contribution of alveolar hypoventilation to hypoxemia?
alveolar hypoventilation is approximated by the excess of PaCO2 over 40mm Hg
100% oxygen is a very sensitive way of measuring ____ ____.
anatomic shunts, a small decrease in O2 content due to a true stung causes a large decrease in PaO2 that is easily measured