felineRN: I think you would enjoy ICU nursing. We have more latitude to do some of the things you are describing without getting griped at.
As you pointed out, it's about what the patient needs in that moment. In fact, I'd be a ****-poor ICU nurse if I didn't react to my pts' needs. If their sats aren't cutting it on NC, they get a Venti-mask or NRB. If their pressure tanks into the 60's, yes, I am going to start a bolus. You can't just let them hang out with a pressure in the 60's or a sat in the 70's and not address it, just because you are waiting for a doc to call you. (At my hospital, it might be 1/2 hour and two more pages before you get a response. By then, it might be too late if you didn't react, or you'd have the ER doc there because you had to call a code. We don't call RRT's, we ARE the RRT.) Granted, I have already paged the doc, and I tell them when they call back, "I took the liberty of doing XYZ, and I'd like to have orders for A, B, & C." And I don't ever give meds or do something like BIPAP without the actual order (unless it becomes an ACLS situation). I will get it ready, though. We wean O2, we advance activity levels, we advance diets after extubation per nursing judgment too.
I will say, however, this would not EVER happen on the med-surg floors. They take a very dim view of doing any of the things I just mentioned. But, for us in ICU, it is perfectly acceptable to our docs.
I agree with some of what you are saying about autonomy. We are insituting an early-warning scoring system. As the scores increase, it triggers different things (calls to doc, transfers to ICU, etc.) It is supposed to catch deterioration of the pt earlier. To me, this is a rote standardization/automaton version of what a good nurse should be doing anyway - noticing changes in VS, mentation, etc. I don't know if this is a "chicken" or an "egg." In other words, are we doing this because the nurses aren't practicing good critical thinking in the first place, or is this a way to take away the critical thinking element to evaluating our pts?
And about anti-intellectualism, I sometimes see this too. I had a pt last week that was dig-toxic and bradying down into the low 30's frequently. According to the literature I was reading, bradycardia from dig toxicity can be refractory to atropine. So, when I reported off to the next nurse, I explained this and said, "So if you need to give something you might want to grab epi, not atropine." He looked at me like I had two heads and six eyeballs. I thought that was important to know, but I guess not. *shrug*
Try ICU nursing; I think you would like it, and be really good at it.