Personally, I've never felt the need to calculate my bicarbonate deficits, largely because I have better things to do with my free time. However, I'm sure many doctors or biology enthusiasts spend hours day-dreaming about it.
If you're one of these type of people then you should find Bicarbonate Deficit Calculator a very useful app.
In order to derive the results, as well as by the conventional mechanism, the program applies the formulas of Pincus and Henderson/Hasselbach with the following parameters: weight, serum HCO3, objective, PH and pCO2.
Of course, I haven't a clue what all this means but from what I can see it performs calculations pretty quickly and hardly dents the memory of your Palm, as it's very small and contains no Runtime.
If you need to calculate and rectify bicarbonate deficits on a regular basis, this lightweight software should speed up the process.