What Causes Delirium And Confusion Post A Back Surgery In An Elderly?

Hello, My name is Kyra Wingstad and I am writing in regards to my grandfather. He is 70, he had polio at 18 months and lived most of his life with leg braces. It wasn t until his 50s that he needed the wheelchair. He has a morphine pump implant, and has used prescription drugs to cope with the post- polio pain. Along with this he has heart issues, diabetes, he has limited function in his legs. The reason I am writing is because he had surgery back in December and since then he has progressively gotten more confused and delirious. He thinks that my grand mother and I are keeping him in some far away place away from his family, he thinks that people are here when they aren t, he docent know how to answer a phone or work a remote. The big issue is he constantly thinks that we are holding him hostage. Following his surgery he was admitted for a week or so due to the confusion and test results he had had 2 strokes a while ago.. Any idea on what this could be or how we could help? Thanks, Kyra Wingstad