Mild pulmonary impairment?

[bluebanded goby]

I didn't get any responses from the M.D.s here when I tried posting a couple of weeks ago on this topic (though I suspect at least some of them were out of town). Before I throw in the towel, I thought I might give it one more shot:

Recently I had a spirometry test which shows that my vital capacity was 98% of predicted, but my forced mid-expiratory flow rate was 66%. The bottom of the normal range is 70%. The doctor said this indicated a possible issue with the small airways. Because I showed only slight improvement after being given a couple of shots of a bronchodilator and repeating the test, the doctor concluded that I don't have asthma. He did say I have "possible mild early pulmonary impairment" from having smoked for 15 years (but quit 15 years ago -- now age 49).

As far as I'm concerned I'm completely asymptomatic -- I don't get any shortness of breath during vigorous exercise or at any other time, and the doctor indicates my lungs sound completely clear. He didn't think there was any issue with diving, but he's not a diving specialist. I imagine there must be all kinds of ex-smoker divers out there who might test in a similar range.

I'm trying to decide if being 4% out of range on this test is worth spending ~$200 for a consultation with a DAN-affiliated hyperbaric physician to take a look at this. On the one hand I suppose the conservative approach would always err on the side of getting a consultation. But it's been my experience with many other medical tests that doctors frequently say, "Oh, don't worry about being a little out of range, we don't treat until you get to twice (or half) the normal value."

Any thoughts? If you were doing a clearance-to-dive and a patient came up with this score, would you clear him? Flunk him? Or would you want to run further tests? Thanks in advance for any reactions.

 

[Saturation]

If in a PFT most are normal but say forced mid-exp flow, one has good exercise tolerance? On no medications for breathing? The forced mid-exp flow is very sensitive, catching very subtle disease, this suggests some minor obstructive disease but without air trapping its of no concern for recreational diving.

 

[GoBlue!]

bluebanded goby once bubbled...
Recently I had a spirometry test which shows that my vital capacity was 98% of predicted, but my forced mid-expiratory flow rate was 66%. The bottom of the normal range is 70%.

If I were your M.D., I would've looked at your FEV1 (how much air you expel in 1 second) & the FEV1/FVC ratio (FVC is amount of air you forcefully expel from full inspiration to full expiration). If the FEV1/FVC ratio is normal, I'd stop there & tell you to go diving. If abnormal, I'd look at the FEV1 to gauge the severity of your airway obstruction & we'd have a talk from there.....

If there's a pulmonologist on the board I'd be happy to be corrected, but it's my understanding that the forced mid-expiratory flow rates (e.g., PEFR25-75) are very sensitive for small airway disease, but there's also a significant amount of false positives (i.e., low specificity). If the FEV1/FVC ratio is OK, I wouldn't worry about it.... But then again, I'm just a kidney guy.

Jim

Standard disclaimer that this does not constitute medical advice applies. Talk w/ your physician.

 

[bluebanded goby]

GoBlue! once bubbled...

If I were your M.D., I would've looked at your FEV1 (how much air you expel in 1 second) & the FEV1/FVC ratio (FVC is amount of air you forcefully expel from full inspiration to full expiration). If the FEV1/FVC ratio is normal, I'd stop there & tell you to go diving. If abnormal, I'd look at the FEV1 to gauge the severity of your airway obstruction & we'd have a talk from there.....

Hi Jim,

Thanks for the comment, I appreciate the input (darn civil of you as a kidney guy). My FEV1/FVC is 89% of predicted, which sounds decent. And the FEV1 was 87%. It was the FEF25-75% that was 66%.

Meanwhile, I'd put in a query to DAN which, as I expected, leaned toward erring on the safe side by suggesting a visit to a dive doc. So I scheduled an appointment in about a week and a half with the local hyperbaric physician/board-certified pulmonologist. It's a bit of a drive, and a fair amount out of pocket, so I suppose I could cancel if I'm feeling confident about this.

 

[GoBlue!]

bluebanded goby once bubbled...

Thanks for the comment, I appreciate the input (darn civil of you as a kidney guy). My FEV1/FVC is 89% of predicted, which sounds decent. And the FEV1 was 87%. It was the FEF25-75% that was 66%.

Well, I'm not your physician & standard disclaimer about this not constituting medical advice applies, but an FEV1/FVC of 89% & an FEV1 of 87% sounds like no significant airway obstruction to me.... I'd ignore the FEF25-75 given the numbers you had, ESPECIALLY since it was JUST outside the normal range. If you had a horrendously low FEF25-75 in the face of normal FEV1/FVC & FEV1, I'd wonder more about the quality of the study & have you repeat it.

So my non-professional, unsolicited advice would be to stop the damn cigarettes & get out and dive, realizing that you could suffer a random act of pulmonary barotrauma just like anyone else, but I don't think you'd be at higher risk than the next guy who's also a smoker (ahem, ahem).

(Of course DAN needs to cover themselves...don't want to get sued for not referring someone with "abnormal lung function.")

Jim

 

[GoBlue!]

Sorry! Just remembered that you're already an ex-smoker of 15 years. I apologize for that portion of my previous post; I was thinking of a different message. Congratulations for quitting - probably the best thing you ever did for your health!!

Jim

 

[bluebanded goby]

No offense taken on the stop-smoking sermon, Jim -- I'm out here in the audience yelling "Amen brother!" On a dive boat just yesterday I noticed a diver up by the bow grabbing a smoke between dives -- can't imagine how anyone could do that (the doctor who did the spirometry test told me that, while I scored 66% on one factor, an active smoker might score ~20%. Not an experiment I'd like to try while running compressed gas through my lungs at varying pressures).

But I do know how hard it is to quit. I started trying after the first pack or two I ever smoked some 30 years ago, and it took 15 years of trying -- along the way trying nicorette, hypnosis, acupuncture, you name it. Thankfully the 15th or 16th time was a charm.

 

[GoBlue!]

bluebanded goby once bubbled...
...it took 15 years of trying -- along the way trying nicorette, hypnosis, acupuncture, you name it. Thankfully the 15th or 16th time was a charm.

What a fine example of NEVER QUIT QUITTING. Congrats, and have fun diving.

Jim