lecture 8 - ventilation/alveolar gases Flashcards
1
Q
What is the mechanism commonly used to counteract pathological dynamic compression of airways?
A
Pursed lip breathing
2
Q
What is the respiratory exchange ratio?
A
Ratio of the volume of CO2 produced and O2 consumed - VCO2/VO2.
3
Q
What is the typical value of the Respiratory Exchange Ratio?
A
0.8 - more O2 is consumed that CO2 produced
4
Q
What is the Alveolar Gas Equation?
A
PAO2 = PIO2 - PACO2/R
where R is usually assumed to be 0.8
where PIO2 is usually assumed to be 150 (room air)
5
Q
What is the significance of calculating the A-a gradient?
A
A-a gradient tells you the pressure difference of oxygen between the arteries and alveoli. An increased difference leads to decreased gas exchange.
6
Q
What calculation can tell you if a patient has a gas exchange problem?
A
A-a gradient
