Don't Wanna Be Sedated

So our son is to undergo some testing tomorrow for a facial tic that developed literally over night. Ideally they would sedate him for the testing, but we are very uncomfortable with that prospect, especially considering he was hospitalized a month ago with serious respiratory complications and the number one risk of sedation in children is respiratory decompression. Anywho, I informed the nurse today that we would refuse sedation and she basically kept talking over me saying, "Well, let’s just plan on sedation and then you can talk to the nurse practitioner about your concerns when you get here." What part of "WE WILL REFUSE SEDATION" was unclear or confusing for her? It makes me angry because obviously they want what is easiest and quickest for them. I don’t give a flying rat’s ass about their convenience or ease of job duties. My concern is what is in the best interest of my son and if the test can be done without sedation, albeit a bit more difficult and time consuming, then I’d rather fight that fight. So, talk to me….am I just being paranoid and overprotective? Or am I merely exercising my rights as a parent and doing what we feel is in the best interest of our son?