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Flashcards in Friday, 11-21 CIS Deck (18)
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What characteristics are associated with obstructive lung diseases?

Difficulty exhaling
Increased lung tissue compliance
Decreased elastic recoil
Breathing at larger volumes
Decreased breathing frequency
Problems with airflow


What are some examples of obstructive lung diseases?

Cystic Fibrosis


What are some characteristics associated with restricted lung diseases?

Difficulty inhaling
Decreased compliance - lung tissue or chest wall
Enhanced elastic recoil
Breathing at lower lung volumes
Increased breathing frequency
Difficulty expanding the system


What are some examples of restrictive lung diseases?

Interstitial lung disease (IPF)
Muscular dystrophy


In plain english, what is the relationship between mechanics and the work of breathing?

Potential energy is built up in the lung tissue during inspiration
- analogous to elastic recoil

Energy is released during expiration, which overcomes any resistive forces and allows the lungs to resume their uninflated proportions and expel air


What happens when you increase the breathing rate in terms of airflow, work, and tidal volume?

Increased breathing rate leads to increases in:
viscous/flow-dependent work
tidal volume
elastic work


What does a decrease in the slope of a curve in a graph charting the relationship between lung volume and transpulmonary pressure? An increase?

A decrease indicates fibrosis, or a restrictive disease with problems with inhalation

An increase indicates an obstructive lung disease with problems with exhalation

A decrease in slope, with an inability to build up lung volume despite a significant increase in pressure can indicate surfactant problems


What do surfactants increase?

Lung compliance


What are the 3 mechanical functions of surfactants?

1. lowered surface tension
2. increased alveolar stability
3. keeping alveoli dry


Without surfactants, what changes would you expect to see in lung tissue?

Stiff lungs
Alveoli filled with transudate


What would an FEV/FVC ratio look like for someone with a restrictive lung disease?

A high ratio >90% or more

Patient is unable to move much air in, but can generally breathe out the small inhaled volume
- leads to a higher than normal ratio, even though the actual values for the numbers are smaller than normal
- lung volumes are lower than normal


What would an FEV/FVC ratio look like for someone with an obstructive lung disease?

A lower than normal ratio <60%

Patient is able to inhale normally, but cannot exhale the inhaled volume


What disease would you think of if the path report from a lung biopsy shows "honeycombing", "fibroblastic foci", and dense fibrosis? Is this disease restrictive or obstructive?

Path changes characteristic of IPF
- restrictive


What lung volumes and compliance changes would you expect with IPF?

Decreased vital capacity
Decreased Functional Reserve Capacity
Decreased compliance


How would IPF affect gas exchange? What would you see on an ABG? A Dlco?

Negative affect - thickens blood-gas barrier
ABG - would show low pO2, normal to low pCO2
Dlco - decreased


What is lung compliance equivalent to?

Change in volume over change in pressure

Also, inversely related to lung elastic recoil


How does kyphoscoliosis change the pressure-volume curves?

Decreased total lung capacity
Decreased chest wall and lung compliance
Decreased functional reserve capacity


What changes to lung volumes would you expect in an obese patient?

Decrease in all lung volumes
Decreased FEC/FVC ratio

Increased Dlco, probably to compensate