PFT--Diffusion test--what is VIN?

[starion]

Dear LungLine Nurse,
What is VIN in a diffusion test of a PFT, please?  My kids just had PFTs & their VIN rates were low (63% & 69%).  The respiratory technicians who were in the PFT lab didn't know what VIN stands for and what the significance of a low VIN rate is.
Thanks.
Starion

[National Jewish]

VIN stands for vital capacity in.  This is the depth of the deepest breath you can take in after completely empting your lungs.

The VIN measurement should be close to the vital capacity measurement.  The significance of the VIN is to be sure that the diffusion test is accurate.  The VIN measurement usually shows on the initial data sheet, but not on the final report.

[RTFLY]

Hey Starion...I am curious myself. I am sorry that the respiratory therapist's in the PFT lab didn't know what it meant either. I do not do many PFT's and have never performed a diffusion test(I teach mostly critical care). I have asked a few colleagues what it might mean and to my suprise...they don't know either! I am looking forward to the RN's response. If anyone will know, he/she will. Take care...
                                                   JCI, RRT RCP

[starion]

I promise to post any answer I get from my allergist or pulmonologist.  I'm also puzzled as to why my husband & I have never had a hemoglobin test in connection with our diffusion tests but they want one for each of the children.  I've had my diffusion rate tested in connection with a PFT m-a-n-y times & never had a hemoglobin test with it.  My husband has only had one, at National Jewish, and no blood test either.  We're very puzzled.
Starion

[starion]

Dear LungLine Nurse,
Thank you very much for your response.  It is helpful to understand these abbreviations and I will share your information with the PFT lab and everyone who reviews my children's medical records.
Starion

[RTFLY]

Glad the RN knew. I had no idea. As I said, I do not do many PFT's and the ones I do perform are bedside that are not as involved as a full PFT. Vital Capacity is abbreviated as VC in most context. Maybe thag is why it threw off the PFT lab as well. In any event, glad we found the answer. Take care everyone...
                                               JCI, RRT RCP

[starion]

RTFLY, LungLine Nurse & Everyone,
The RPT at the PFT lab said that since I last spoke to him, he guessed that the VIN was as the LungLine nurse advised us.  He also said that as long as the VIN is within 80% of the VC, the test is OK according to the American Thoracic standards, which he has passed on to the pulmonologist (who also asked him about VIN per my e-mail to him).  We calculated & determined that both children's results were within 80% of the VC.
Thanks again!  It's helpful to have a better understanding of these abbreviations; it helps de-mystify the testing and results.
Starion--grateful in HI