not waking up after sedation

[cassiernall]

My mother had surgery March 9, 2016, on her colon for diverticulosis and they removed a piece of her colon. Stitched her back together and she ended up leaking from where they pieced her colon back together, which led to an infection in her stomach, They took her back in for emergency surgery on March 12, 2016 and gave her a colostomy bag.As told to me by the doctors, she wasn't breathing very well so they stuck on her a ventilator. They kept her on sedation meds in the SICU called propofol. She was sedated for 3 weeks straight, they took her off sedation and she was still a little out of it and not very responsive, mostly sleeping. They moved to Select Care for long term acute care and since then shes only been receiving Oxycontin 10mg and Ativan 1mg every 6 hours for pain and to keep her calm. She's completely out of it, won't respond to anything, basically laying there as if she were lifeless. She's still on the vent. Does anyone know what could be wrong as to why she's still sleeping and not responsive to touch, voice, nothing? please help.