Ashton Kutcher -- Fist-Pumping After Demi Moore Emergency

Just one night after Demi Moore was rushed to the hospital for inhaling too much nitrous oxide -- Ashton Kutcher hit up a Bruno Mars concert in Brazil ... where he fist-pumped his brains out.

The video was shot the same night Ashton dropped by a nightclub in Sao Paulo with a mystery female companion in a red shirt -- the same girl is standing beside him at the Bruno Mars concert.

As we previously reported, Ashton gave a Brazilian photog the cold shoulder when asked if Demi was okay -- giving no answer.