Physical Therapy with Pulmonary Fibrosis

Have any of you done PT while being short of breath from Pulmonary Fibrosis, Interstitial Lung Disease, or other breathing problems?
My 83 year-old hubby's orthopedic/spine surgeon wants him to schedule physical therapy now that it's 2.5 months after his second Kyphoplasty for spinal compression fracture, but he's been reluctant to call the PT office, due to having increased difficulty breathing with even minimal exertion. He has recently needed to use his portable oxygen concentrator after things like showering or getting dressed. He's also still having to take a half cyclobenzaprine muscle relaxer and half a hydrocodone for back pain, so he can't even drive, yet -- due to possible drowsiness. Before the back surgery, he was driving to his part-time consulting every day. Now, he's okay as long as he's just sitting in his recliner, but does get up and slowly walk around the room a few times, several times a day. Also currently taking Azathioprine for Rheumatoid Arthritis, which we suspect has had some negative side effects after taking Methotrexate for 20 years -- and which we (and his doctors) believe has been the cause of both the osteoporosis fractures and the pulmonary fibrosis, as well as the MGUS which was discovered during his first Kyphoplasty 2 years ago. He's supposed to start an annual Reclast infusion for the osteoporosis in April, and we're dreading that -- as he seems to be susceptible to every possible side effect of everything he's ever taken.
We really don't know what to do. Would a Physical Therapist be able to deal with all this, and how???