You could apply the penalties from the critcials to all actions, including RRs.
Also there's a modifier to initiative that says: "If 50% of your total hits are lost, then you have a -25 to initiative".
This rule is used as an initiative modifier, but I guess it wouldn't be out of place for everything else, i.e. if 50% of total hits are lost, then every action has a -25 penalty.
But as Ecthelion says, there's nothing like that in the rules.