Here's the post for you that I wrote on the "damaged esophagus" thread:
Sorry you're struggling. I don't think you have to worry about your lungs in regards to sedation. First of all, you're not going under general anesthesia...they use a drug that relaxes you and puts you out a little while the endoscopy is being done.
I have asthma, and was having a lung infection and serious breathing problems when I had my Nissen fundoplication surgery. At that time I was worried that I might have an asthma attack while under general anesthesia (a much more severe version of what you'll be having). A friend of mine who was a nurse-anesthetist told me that they put medicine in the anesthesia tube that helps asthmatics and eliminates that worry. I had the surgery and didn't have any problems as a result.
I've had an endoscopy 3 times. The first time I was aware and awake, but under a very mild sedative. I remember the procedure and actually helped swallow the endoscope, but was very relaxed. The second time I chose to do the procedure without any sedation. This works fine if you're motivated and have a good nurse to talk you through it. The third time I asked to have very little sedation, but was put out, as I remember the doc coming in and talking to me and that's the last I remembered until the whole thing was done.
As long as you make your GI doc aware of your lung issues, he/she will be able to determine whether or not it is a problem that would contraindicate the sedation. I really, really doubt that, but since I'm not a doctor, I'd suggest you call your GI Doc's office and/or the office of the doc who diagnosed you, to ask the question and set your mind at ease.
Don't worry about the endoscopy procedure. It only lasts about 5 minutes, and most people are put out for it, so you don't even remember anything. There is always the option of no sedation, but I don't recommend that for the first one. You should at least have them give you enough to relax you. You could request that be allowed to be awake but medicated if that would ease your mind.
It seems to me that if you contact the doctor who diagosed you with LAM, he/she will be able to tell you if there is a risk in doing the procedure.