DLCO help

[lilii89]

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Hey everyone,

Quick question, if you all could chime in that would be great and really appreciated too 🙂

As far as DLCO is concerned, what is the mechanism behind an increased value for both asthma and a left -> right shunt?

Thanks in advance 🙂

 

[lilii89]

okay the left to right shunt increases the volume in the right ventricle, frank sterling takes over and causes an increase of blood going through the pulmonary circuit -> increased dlco. (at least I hope my reasoning here is correct)

Still confused on the asthma one though :😕:

 

[NMDO]

It is increased in Asthma due to the increased alveolar-capillary surface area, which is due to hyperinflation of the lung.

 

[Chrissisissi]

You need to look at Ficks Law. Amount of diffusing oxygen over time = (p1-p2) *area* D/ thickness. These are the factors that affect diffusion. If surface area is decreased the DLCO will be lower suggesting collapsed alveoli and or edema. If the thickness if the membrane is increased (edema, connective tissue diseases). Asthma is caused by construction of the airways and shunt causes V/Q mismatch. I was under the impression that vq mismatch which can be caused by asthma and shunt and decreased DLCO were separate causes of hypoxemia and that connective tissue diseases (sarcoidosis) and edema were the diseases that have to do w low DLCO.