Everybody is different. It could be your mom is dehydrated and that can cause the weakness and confusion. The very end stages of most cancers are being extremely tired, no appetite, and little thirst. You need to talk with the nurses caring for her and the Dr. He needs to change her anti-nausea meds-zophran is a good one, it does not make you tired like the phenergan. Bless you for being there with her. Cindy