Friday, 11-21 CIS Flashcards
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?
COPD
Asthma
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) Sarcoidosis Obesity Scoliosis Muscular dystrophy ALS
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: airflow 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?
- lowered surface tension
- increased alveolar stability
- keeping alveoli dry
Without surfactants, what changes would you expect to see in lung tissue?
Stiff lungs
Atelectasis
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
