I really attached to nurse when I was 15 being in hospital for a week, then I came home and never met her again, even didnt know her name and I missed her.

You can invite him on facebook if you know how to find him and when you are out of the hospital maybe you can meet or if you want you can try to do something being in hospital but I think he would be scared that his coworkers or other pateints would know something so he would avoid from it because he doesnt want to lose his job but who knows... Good luck