I've learned through experiences with both of my parents (my mother, who recently died, and my father, who's in the hospital now). They both have regular GP's that have been treating them for years, yet they both said that when my parents went to the hospital, they could not be involved in any way.
Now, i understand the idea that when you go to the hospital, you have specialists and all that, and your GP would not be qualified in comprehensive treatment. The hospital needs to take over treatment. I get that. But i would think that the hospital would want to speak to the doctor who has likely treated the patient for years and knows their medical history better than anyone. The personal physician can ask questions about further treatment, and then be available to comfort the patient, especially if it's likely an end-of-life issue.
As i'm sure you know, elderly folks are often easily afraid and uncomfortable with new surroundings, especially if they anticipate their life is in jeopardy. Both my parents were very upset by not having a trusted doctor able be to drop by and tell them, "You're in good hands."
Does anyone know why patients' personal doctors are completely cut off from the patient when they enter the hospital? I have a feeling it wasn't always this way.