There is a interesting formula for minute volume correction according to PaCO2:

Desired MV = (actual MV x actual PaCO2)/calculated PaCO2

MV can be splited - MV = Tidal volume x respiratory rate; this helps to simplify calculations when you have only RR.

calculated PaCO2 is derived from the Winters formula.

It works for controled ventilation and some types of SIMV.