Your parental rights end at the door, sorry.
I was reading this story about a parent that was upset about a notice that a nurse would have a private consultation with her daughter. As the patient, the daughter had to agree to disclosing any information and it enraged the mother, apparently. There's been back and forth between the mom and the hospital over the situation.
Now, I'm interested in the age range this would encompass. My ten year old should not be able to exempt me from his records, I think anyone would agree with that. But my 16 year old? Or like this article, the patient was 17? I don't love it but I can see why it is done, from the medical standpoint.