Helen, I have no definitive answers re Decadron and Nitrous Oxide. But the decadron, if I am not mistaken, is like prednisone (corticosteroid) and is compatible with bf. Mom will probalby get a low dose for swelling or something like that. The nitrous, I would think would be like other anesthetics, when she is alert, etc. it would seem OK. Esp. if we are talking an older baby or toddler. Laurie Wheeler, Rnc, Mn, Ibclc Violet LA