3. Lung Compliance

Question 1

Think of compliance as the degree of ____

Answer 1

elasticity of tissue. Therefore, a decrease in compliance increases resistance or stiffness.

Question 2

Static compliance:

Answer 2

measurement of the elastic properties of the LUNG

    Tidal Volume ÷ PLATEAU PRESSURE (minus PEEP)

-note: increase in plateau pressure will decrease
compliance

Question 3

Dynamic Compliance:

Answer 3

measurement of the elastic properties of the AIRWAYS

Tidal Volume ÷ PEAK INSPIRATORY PRESSURE (minus
PEEP)

note: increase in peak inspiratory pressure will decrease compliance

Question 4

Normals for both static and dynamic compliance

Answer 4

Normal for both static and dynamic compliance:
~ 45 - 50 mL/cm H20

Question 5

Patients with pulmonary problems that mainly involve the airways (e.g —)…

Answer 5

(e.g. asthma) have a decrease in dynamic compliance, but their static compliance remains normal (fig. 4 - 11)

Question 6

Pts with pulmonary problems that mainly involve the lungs (e.g. ___)…

Answer 6

(e.g. pneumonia, ARDS) have a decrease in static compliance, but their dynamic compliance may also decrease as the lung pressures may transmit up to the airways (Figure 4 - 11)

Question 7

Status asthmaticus:

Answer 7

-static compliance (lungs) would be normal
-dynamic compliance would be low

Question 8

ARDS:

Answer 8

-static compliance would be low
-dynamic compliance would also be low.