I had a patient last night that had continuously complained of "24/7" nausea since she had been admitted. She was not sleeping well, was anxious and restless. The nurses before me had asked the doctor for an antianxiety med and for some unknown reason her ambien was dc'd so that wasn't an option either. This patient had pulled her IV out and didn't recall pulling it out. While I was restarting it I talked to her about how she was feeling. She was having difficulty expressing herself. I knew she hadn't slept the night before more than an hour, nor had she slept during the day and now it was almost midnight again. I let her sit up in the bedside chair while I restarted the IV but then after I got it in I told her a lot of her anxiety and "feeling crazy" (as she called it) was most likely due to lack of sleep. I got her back in bed and told her it was time to relax and close her eyes, turn off her TV and attempt to sleep. I flushed her IV with saline (since it was a new IV). She thought I was giving her some sort of medicine. I did not confirm or deny it. I just said, "it's time to relax now". She ended up sleeping the rest of the night. At 0530 she woke up to void and asked if she could have "some of that same great medicine". Again, I didn't confirm or deny it and our saline flushes are due at 0600, 1400, and 2200. Since it was 0530, without a word, I flushed her IV again. She said thanks and went back to sleep. In my report to the oncoming shift I mentioned her thinking the saline was a med and said, "it seemed to work great". Well, the nurses (after I left of course because heaven forbid someone actually say something to your face) all gathered at the nurses' station and were talking about the legal ramifications of what I had done, giving a placebo without consent, etc. I heard about it from one of the night shift nurses who stayed late to chart. She said, "I hope you didn't chart it anywhere". I had charted that the patient had complained of nausea all night but stated it was gone after I flushed her IV with saline. I also charted that the patient asked for the "same great medicine" meaning the saline but didn't mention that when she asked for it like that I gave it to her. I charted it simply because i thought it spoke to her mental status. Personally if I were a doctor or NP I would want to know that the patient felt better even though she was given nothing. My concern is, did I truly do something wrong here?