Granny, so happy to hear that there is no blockage. If nothing else, see if you can get him to at least do the breathing test again. Like my lung specialist said when I told him my earlier breathing test showed I was doing good for my age. He said the lungs change as you get older.
Just getting him to go back for a follow up visit will be a chore so.....
His sister went through all the same testing several times and finally a cat scan caught a leaky valve.
We need to pass this info on to his specialist.
Our SIL is home from hospital, didn’t find anything.