This is a randomized, placebo-controlled trial of the reversal of dabigatran and rivaroxaban using prothrombin complexe concentrates - which, most importantly, have been theorized to be the only used agent for dabigatran. Their results - in groups of 12 healthy volunteers - is that PCCs have no effect on any of the laboratory clotting parameters for dabigatran, but fully reverse rivaroxaban.
So, while there are no studies as of yet describing the acute reversal of either of these agents in a clinical situation, this is definitely concerning that we still have no theoretical way to treat life-threatening bleeding with dabigatran.
"Reversal of Rivaroxaban and Dabigatran by Prothrombin Complex Concentrate."