I would do as Sarita suggested. You may have received Potassium in the IV. Potassium is very irritating to veins and that may account for the sensation. Also sometimes where the IV is located and the size of the vein used can cause irritation to the vein.
I agree if you notice any of the sx mentioned above, call and ask the ER re your concern.
It is a good concern, so please do not worry about how many posts...........that is why we are here.
J J J