No need to be baffled ... in general, syringe pumps deliver drugs, whilst infusion pumps deliver fluid volumes.
There are always special cases, of course. For instance, when "piggy back" infusions are used with volumetric pumps (where a drug may be infused together with a volume of some other fluid via a secondary line).
Anything more than that, you will need to be specific about what drugs you are pumping, in what volumes, and in what concentrations.

See also
TCI.