concurrent piggyback

correct me if i'm wrong but concurrent piggyback ivs are for when your secondary iv run for a lesser amt than the primary?

today in my clinical my pt. had a piggyback of piperacillin 50 ml so VTBI/hr is 100ml/hr

primary i believe, sorry for my faulty memory is NaCl 9% w/Kcl 20meq/ 1000ml @ 20ml/hr

my pt's other iv piggyback was a Mag Rider @100ml/hr

my other question is when do you do or when is it advisable to do a piggyback or a concurrent iv

This is a difficult question to answer since we don't know what your definition is of concurrent and piggy back. Here is how I would run all the fluids you listed above.

First of all, you are going to need two IV's or all these infusions will take too long. You don't mix antibiotics with potassium. I think you have the size wrong on the potassium too, are you sure it wasn't a K rider?

IV #1 - 500 ml bag of NS (NaCL 9%) as primary running at KVO rate (20 mL would be fine unless it is a renal case, then use 5 or whatever hospital policy is). Hang pipercillin as a piggyback. This line will be for antibiotics only and for the primary line.

IV #2 - Another set up as IV#1 for infusion of K rider. Set up the mag rider on another pump and run it concurrently with the K rider. Plug in mag further down the line to run it concurrently. They are compatible.

Run through one IV - Set up as IV#1. Run pipercillin on time as scheduled. When done, change piggyback tubing, change pump settings and run K rider and plug in down the line the mag rider.

Of utmost importance is knowing what the primary fluid is infusing. You don't mess around with potassium without being 100% sure of what you are doing with it. (You could say that for any IV drug, but particularly K!)

Now, if you have a PICC line or central line the whole set up is going to change and make your life much easier.