PCA Question

I had a patient the other day that transferred to me from another unit. He had a PCA pump. While I was going through his orders, I noticed that a basal rate was ordered, however, there was none programmed in.

I called the prior nurse and asked her about it. She said she changed the settings, stating he was too lethargic for a basal rate, but kept the demand because the patient was still in pain. She said she called the MD (with no answer) at 1000 and had been too busy to follow up. It was 1700 when he came to me. An hour later I notified the charge nurse and she said she'd get in touch with the MD. Another hour passes, and I charted that the patient came up with a PCA pump, basal rate d/c'd per prior nurse, no orders noted. Because CYA. The doctor called at about 1830 and gave the order to d/c the basal rate. Problem fixed.

The nurse called me later and became very ugly and confrontational about the note. I pass it off as stress and forget it. Before I leave my charge nurse tells me my note was very inappropriate and that nursing judgement allows us to change the order based on the patient's needs.

Now, I learned with a PCA that if a patient is lethargic or begins to have a respiratory issue, nurses may disconnect the pump and the MD needs to be reached. Never do we ever change a medication order without a doctor's approval. I also understand that the patient may have been in pain, but if he's lethargic enough to be completely asleep, I don't see that he needs the PCA at all. Let me note that was had no pain for the three hours he was my patient and was completely alert. He didn't touch the button at all.

My questions are this:

Can we really change part of a PCA order and leave the rest? Was that completely inappropriate to put in a note?

Also, is it far fetched to believe that a patient could refuse the basal rate but not refuse the demand? Because it seems to me that either the patient can't refuse part of a medication any more than they could refuse the NS but not the antibiotic or maybe he wasn't as lethargic as I was led to believe.

Anyway, I just want to know if I need to apologize and do my best to make it right.