What does "comfort measures" (as distinct from "comfort measures only") mean does it mean nurses can give prn im or s/c injections if the need arises?

Possible: Comfort measures is usually used in conjunction with palliative care or hospice. If you are asking about that, yes it could mean any thing like pain medication, oxygen, anti-anxiety medication to make patient feel comfortable along with patients chronic medications. I hope this helps.

Comfort measures.: Comfort measures are treatments for comfort of the patient. A PRN medication is given only when needed.