If she's responsive to pain I don't think she's comatose. Respiratory arrest can be caused by many things - possibly pneumonia, or chest infection,. In would say that is possible considering she was in bed and on a respirator for a while. The pain could very well have caused the breathing problems as well... People tend to hyperventilate when they are in a lot of pain... Did they check to see if she had a bowel blockage? There could be more going on. I'm surprised the dr.s haven't told you anything. It's scary but your mom is frail, and an operation like she had can be a huge shock to the system. I'm not a dr. I wish l could help. Good luck with her... And talk to her while your there - it sounds like she's aware... Though not terribly responsive.