Hi Amelia2013, welcome to ECF.
I'm not a doctor, so I certainly can't advise you to vape if you have emphysema, nor would anyone on this board (probably). That would be a conversation to have with your doctor who hopefully has some knowledge regarding this illness and
vaping.
I can tell you my own story, which was that I had pneumonia on and off for 18 months, prior to switching to vaping. My lung health has improved immeasurably and I no longer wheeze, need inhalers, or any other lung aids. I caught a cold and for the first time in years, it did not progress to a bronchial issue. I have also seen other vapers WITH emphysema (even on oxygen) use a vape, and seen reduction in symptoms. What I can tell you DEFINITEVELY is that vaping is harm reduction, not harm elimination. Without more longitudinal data, it's impossible to say that vaping carries 0 risks. It is considered safer than smoking in many countries and via many studies, for sure.
Whether it is a good idea for YOU needs to be discussed with a medical professional, and you need to weigh harm elimination methods. Some folks with emphysema do well not actually inhaling into their lungs, but using a mouth inhale, to nose exhale, letting mucus membranes do the work. Others can vape successfully into the lungs. There are also other harm reduction products that are tobacco based such as Snus, which was developed in Sweeden, for example. You have other nic replacement options.
With that said, if your medical professional gives you the go ahead, I'd advise MTL vaping (less vapor, more nicotine per puff, more similar to smoking a cigarette) over inhaling large volumes of vapor into the lungs (sub0hming). You would want to find a good VG/PG (the two major carriers of nicotine and vapor-carriers) ratio, some folks find too much VG causes a heavy or congested feeling in the lungs, that would not be good with COPD.
I really think the first step is to talk to your doctor about this, and evaluate which options are safest for you to successfully stop smoking, so your emphysema doesn't worsen. It could be vaping, or it could be something else, but please talk to your doctor since this is a very serious condition, and I am not a doctor, I am a random person typing on the internet.
Best of luck, and I hope things go well for you.
Anna