Wednesday, October 12, 2005

PFT dilemna

What causes severe obstruction (40%)with no post-bronch reversibility, and a normal DLCO (80%) in a non-smoker? Here are some extra things: her PFT's on and off Advair were not changed. Her CXR:

12 comments - CLICK HERE to read & add your own!:

Jeff H said...

1) Large airway obstruction
2) COPD (possibly alpha-1) in a non-smoker with extensive second-hand smoke
3) idiopathic bronchiolitis obliterans
4) infectious bronchiolitis
5) chronic asthma with airway-remodeling/subepithelial fibrosis
7) Churg-Strauss
8) Sarcoidosis

I'm sure there are more, many of which I've never heard of...I'll leave those for Carlos.

Jennings said...

No I meant what causes that obstructive picture with *NORMAL* DLCO? Most of the things on your list would have a decreased DLCO except for #1 but her inspiratory loop was perfectly round.

Jeff H said...

Actually, most things on my list, especially #5,6,7, and 8, could have a normal DLCO.

Mike L said...

Add to the list:
1. Hypersensitivity pneumonitis
2. COPD with mostly a chronic bronchitis component

A high resolution CT of the chest could help distinguish between some of these...

Jennings said...

To address each of your excellent points of what diagnoses may fit with those PFT values:
1. COPD with chronic bronchitis but she is a nonsmoker and doesn't have a productive cough.
2. chronic asthma with airway-remodeling yes this could be a possibility.
3. HP - this is usually restricitive and the DLCO would go down, especially for with this degree of abnormality in pulmonary mechanics.
More history: On exam she truly did have wheezing.

Baleeiro said...

I like JCH's list. How old is she? I seem to see a lot of older non-smoker women who have had untreated "mild" asthma with rare wheezing that come in with airway remodelling and fixed obstruction (JCH' #5).

Jennings said...

I like the remodeling diagnosis too and that's what I'm going with in this patient.

DKeena said...

Any response to systemic steroids?

Perhaps CHF is contributing to her obstruction and causing a falsely elevated DLCO. BNP?

I agree that an HRCT would be helpful.

An FEV1 fixed at 40% predicted seem a little low to me for asthma remodeling, albeit possible. I would be more worried about idiopathic bronchiolitis obliterans.

Jennings said...

BNP is normal. EF 55%, but CXR is as above.
There was no response in FEV1 with or without ADVAIR.

Mike L said...

You indicate HP is usually restrictive with a low DLCO. I agree. It usually is.

However, there is literature indicating the HP can be manifest by PURE OBSTRUCTION.

Lalancette M et al. ARRD 1993; 148(1):216-21

In fact HRCT can look like emphysema. Granted, this above article speaks of Farmer's lung, but I believe that it is probably applicable to all forms of HP.

Before you chalk this up to IBO or chronic asthma with airway remodeling, I would urge you to get a HRCT.

Just my 2 cents.

Arenberg said...

This looks like humongous adenopathy and maybe a large heart as well. Maybe sarcoid(with or without cardiomyopathy)? Sarcoid can give you obstruction withougt affecting the DLCO to the same extent.

On the other hand, CHF is always possible if you have a cardiac silhouette that large.

Baleeiro said...

JJ, would you get a HRCT already?