Horizontal,
If your breathing problems were not caused by surgery ,
do you mind if I ask how your doctors think that your phrenic nerve was injured ( I hope I'm using the right termonology here)

Bigpede,
I'm glad the you can get a little sleep on the Bipap.
When I was hospitalized for an acute asthma attack and aspiration pneumonia they put me on the bipap machine. I was barely conscious and kept trying to take it off.
When they said if I didn't leave the bipap machine alone that they would put me on a ventilator- it woke me up enough to leave the bipap machine alone.