Dr. Order for elevated head of bed?

Hey all, I'm fairly new to NICU. I was a psych nurse for 2 years and had to most amazing doctor possible. He definitely was not the stereotypical doctor you hear about in nursing school. Now I switched hospitals to work in the NICU and all I'm hearing is how the doctors treat and think the nurses are stupid, questions everything a nurse does. We had a desat, down to about 42, a little over 30 seconds. Mild stimulation was needed. The on-coming nurse asked for every detail because the doctor is going to ask if it was a true desat. I work nights so do not have much interaction with doctors other than the 1 rounding done during my shift so I haven't encountered anything like that yet. The baby I had been taken care of finally got out of her isolette, I was so excited. She has reflux pretty bad, spits up all the time, so to me, the 1st thing to do it put the head of bed up right? We left her head of bassinette up almost the whole time she was in the isolette. So when I went to work and she was out, I put her head of bassinette up. My preceptor came by and told me technically couldn't do it because I didn't have an order. Where I work, we don't have to have an order to elevate head of bed in an isolette, but if in a bassinette, we do.

My problem is, I thought elevating the head of bed was a nursing measure. It's one of the first things we do for aspiration, SOB, etc. I have asked nurses but no one seems to know why we an order. I asked, and all they say is that "Nurses don't know when it should be elevated and we can't say the baby has reflux because we would be diagnosing the baby. I thought that was "treating the symptoms" though, which is the primary practice in our scope of practice. We treat the symptoms. Is there something I am missing here?