I always find it so annoying that medical professionals expect parents to discuss their concerns with the kid sitting right there. I usually tell the nurse ahead of time that there are things I want to discuss without the child present, and they find somewhere for him/her to go, or I just tell the child to step into the hallway for a few min. Some clinics have an x-ray or lab waiting room that isn't that far away. Of course, then the kid may get concerned about what it is they aren't supposed to hear, but then at least you can speak openly without worrying about their self esteem.