I don't understand no oxygen until it drops to 59. At that level he would probably pass out or be gasping for breath. The oxygen should never go below 90 for very long. When it does, damage is being done to other organs. I would suggest also that you seek help from a Dr that specializes in pulmonary fibrosis. A regular GP doesn't have the knowledge your husband is going to need. My husband had a local lung Dr but he also went to a specialist at the Mayo Clinic. They helped him and me tremendously to understand and prepare for the journey we were on.