Suggest Treatment For Severe Emphysema Causing Tiredness And Brown Sputum

My husband has severe emphysema ,he is on oxygen, he is 60 years old and very underweight. He has had emphysema for 10 years, the last two weeks he has done nothing but sleep for 18 or more hours a day and he has no energy to even sit up. He had an infection and eas treated with Azithromycin and prednisone a month ago and now his sputum has started to be brown again, i am very worried about his lethargy and all of this sleeping,any suggestions. he kust started the antibiotics and prednisone again today as we always have a back up at home.