I'm sorry for your son's CF diagnosis, but it's great that his numbers look good and he's doing well. I do not know alot about atypical CF but I think preventative care is always a good thing. It seems reasonable to learn how to do CPT/nebs in case he gets sick. Some CF docs do put patients on CPT regardless of lung involvement because CF is a progressive disease. Of course, encourageing an active, healthy lifestyle is a good preventative thing in CF; sports, exersize, well-rounded healthy diet with good fats(omega3 fats). Your son should be very involved in learning about CF as he is so close to becoming an adult.