My pulmonologist wants me to give a sputum sample to test my sputum eosinophils so we can get a better picture of what's going on in my lungs. I'm wondering: how do you give a sputum sample if your cough is normally nonproductive? What's involved with this procedure? I've never done it before and I don't like going into things ignorant and unprepared.
That's a great question.
First you should know that normally, healthy individuals do not produce enough sputum to cough up. So that's a good thing. If you're producing enough phlegm to cough up, your in one way or another sick. So not produing sputum is a good thing.
I would say that the best way to obtain a sputum sample, and most common and humane, is by you spitting it up into a sterile cup. This is usually done in the lab, or doctor's office. Yet I'm sure you already knew this.
So the other methods.
One is to nasal-tracheally suction. This is where we stick as sterile catheter into your nose (or mouth, but usually nose) down into your lungs to suck sputum out.
However, by my own experience doing this, if you are awake, alert and orientated (AAOx3) and can't produce a sample on your own, this method probably won't work either. Healthy people do not produce sputum.
Likewise, it's a very invasive procedure, very uncomfortable, and in my opinion, inhumane to do on an AAOX3 patient.
A third method is to do a bronchoscopy. This might be nice to have done anyway if your asthma is really bad so your doctor can see what exactly is going on in your lungs. Plus you are put to sleep for the test.
Yet, in my opinion, I wouldn't let a doctor do this unless he had a reason other than to obtain a sputum sample.
I think the best way to obtain a sputum sample is for your doctor to give you a sterile cup and let you produce one on your own time. If you're not producing one, he'll just have to wait.
Keep in mind this answer was based on my own personal and professional opinion.
He said he suspects allergic bronchopulmonary aspergilliosis is the most likely explanation for why my asthma decided to go crazy 18 months ago, but I don't know if you need a sputum sample for that. He's also ordered a skin test for aspergillus allergy (I've been tested for general local moulds and it came back inconclusive, but this test is more specific, he said). I've also been sent for blood tests for eosinophils and IgE.
As for the suctioning, that definitely doesn't sound very pleasent! If they suggest it, I'll definitely grill the person performing the test about whether or not they believe it's really necessary. I'd rather see if they can wait until I'm having a bad day and just take it then (since on bad asthma days, my cough is sometimes productive... on good asthma days, I still cough, but not as much and it's non-productive, plus my exercise tolerance is higher and I just generally feel a lot better).
Or did I misunderstand the question? I thought of a couple other ways a doctor might try to obtain a sputum sample. One is to try an Albuterol breathing treatment. Actually, this method is pretty common, although this usually doesn't work. Another method is to give a breathing treatment with a hypertonic solution, which means the salt in the mist is greater than that of the cells lining your air passage. In theory the extra salt is supposed to draw fluid (phlegm) from your cells, and thus help you cough it up. The idea here is noble, although after years of studies, there's still no evidence this works. Both these methods are easy with essentially no side effects.
I doubt your doctor would order any of those invasive things I described above, yet I thought you'd want to know all the things he could have you endure if he was that kind of guy or gal. And you'd survive all of them.