Amperage is what the 4e rules use to determine electric damage, so the document you reference would be useful to help the conversion.
For these rules to work, we need to make sure all the types of damage that can happen are addressed in some manner. The list is:
Ballistic
Explosive
Impact (including hand-to-hand)
Electricity
Burns
Hyperthermia
Hypothermia
Starvation/Dehydration
Poison/Venom
Radiation
Some are more important than others, since you can arrange a game to almost ever encounter the problem, and others can be handled kind of trivially.