Father is hospitalized with good prognosis of full recovery from colon surgery, his wife is opposed to this, afraid he may burden her is some way. He is able to make his own decisions still, but is very sedated and weak. She has tried to deny him care such as antibiotics or iv fluids, but we (his children) have been able to wake him and have him verbalize his desire to continue. She went as far as trying to demand they put him on a ventilator so she would have a "plug" to pull. Now she is trying to deny his children access to even visit with him or be present when the Dr. evaluates him. The hospital staff can be different from day to day. One day they say no she cant not refuse us, and the other that she has all the rights legally and we have none. We need to know if it is time to pursue some legal intervention just until he is out of the hospital.
If these are in place; then she is the only one to whom they will provide information. My experience with hospital staff is as you said - varies day to day depending who is working. They don't all adhere to the same rules. But would definitely consult a lawyer as soon as possible. You need to help your father as this woman is dangerous, from the sounds of it.