As Newgene said, if we don't count alcohol as a carbohydrate, because I assume that we're looking to do something similar to conglomerate beer in the "low carbohydrate" area, then perhaps we could let the beer ferment out, then use a wine yeast to drive the FG even lower. It would leave you with a VERY dry beer with a high ABV. I'm not saying it'd be good, or bad, but if you wanted to get rid of the residual sugar, this could be one way to go without a lot of factory equipment.
If you want no carbonation, then bulk aging is your friend. If you're brewing a lower ABV, or just not patient, then look up a wine degasser.