Jan 4, 2012
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Passage:
Expiration becomes difficult in emphysematous patients because bronchiolar obstruction increases airway resistance. This resistance is already elevated during expiration due to the compressive force on the outside of the lung. Slowing of forced expiration is the most reliable indicator of chronic emphysema



Thought that it should show a smaller total lung capacity? I'm confused
 

MedPR

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Passage:
Expiration becomes difficult in emphysematous patients because bronchiolar obstruction increases airway resistance. This resistance is already elevated during expiration due to the compressive force on the outside of the lung. Slowing of forced expiration is the most reliable indicator of chronic emphysema


Thought that it should show a smaller total lung capacity? I'm confused

Is A correct?
 

MedPR

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Well B basically says that you never have an increase in lung volume. If you inhale your lung volume should go up some. I bolded the part of the passage (previous post) that led me to the answer. If the forced expiration rate decreases, that means the lung volume will be higher for an extended period of time compared to a normal person. Graph A shows this.
 

Morsetlis

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Well B basically says that you never have an increase in lung volume. If you inhale your lung volume should go up some. I bolded the part of the passage (previous post) that led me to the answer. If the forced expiration rate decreases, that means the lung volume will be higher for an extended period of time compared to a normal person. Graph A shows this.
This is correct.

Emphysema is an obstructive lung disease that lengthens the time it takes to exhale because of dynamic airway compression and loss of the elastic fibers to oppose it.
 

gettheleadout

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I just assumed that because it said emphysema resulted in airway resistance and didn't specifically say that it actually reduced lung capacity (it would just take an emphysema patient longer to inhale/exhale as fully as a normal person) that there was no reason to assume a significant difference in long capacity.
 

Morsetlis

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It is helpful to think clinically of a COPD/emphysema patient with barrel-chest full of air that they cannot expire. In fact, you should probably go watch some YouTube videos to solidify this concept in your mind.