Hi I am worried about my Dad who is 77 years old. He had open heart surgery 20 months ago and came through it great. Before he went into surgery his kidneys were only functioning at 20%. Over the past two months he has been complaining about lower back pain, being cold and has started to fall asleep during a conversation. My question is when he goes to see his family doctor what types of testing should he have done to see if his kidney has failed any worse than it was when he had his surgery. We live in a very small community and it is hard to get a referral to see a specialist.