At my hospital, we also have 2 protocols. All pit is mixed 20units to 1000ml LR.
Rapid (most often used): start at 6mu/min (18ml/hr) then increase to 12mu/min (36ml/hr) in 30 min. then increase by 2mu/min q 30 min until adequate labor/cervical change is achieved or a max of 30mu (90ml/hr) is reached.
Slow (rarely used): start at 3mu/min then increase by 3mu/min q 30 min until """" as above.
The rapid protocol can definitely cause some hyperstimulation problems as you can imagine, but the docs prefer it because it gets the labor "jump started" so they can get them delivered by 6pm. LOL.