When you are hanging a piggyback to infuse with another solution how do you set it up so that it will pull both? For example, If you are ordered to hang magnesium sulfate on your saline locked patient. I was told that you nee to piggyback the magnesium sulfate into LR and run at 50/hr. so doesn't that mean that the LR and Mag need to be infused together? How do You set it up so that the pump will pull both fluids. I know usually you raise the piggyback higher, but then won't it only pull the mag by itself? I'm just confused on how to set this up. Please help!