It doesn't matter if it is NS or Sterile Water. This is extremely old thread, and those were probably the initial instructions a long time ago.
The differences that you will see with repeated dosing in the same patient is usually d/t context sensitive half lives.
"Infusion solutions of vecuronium can be prepared by mixing vecuronium with an appropriate infusion solution such as Dextrose Injection 5%, Sodium Chloride Injection 0.9%, Dextrose (5%) and Sodium Chloride Injection, or Lactated Ringer’s Injection."
http://www.globalrph.com/vecuronium_dilution.htm 
Nov 5, '11 by RN_PICUI would stop doing that, and strictly stick to the instructions!!!! I know its much easier to grab a syringe with 10cc of NS and squirt it down, but if anything goes wrong for what ever reason I would not like to be in a position of explaining why was NS saline used and not sterile water!!!!
Nov 5, '11 by wtbcrnaIt doesn't matter if it is NS or Sterile Water. This is extremely old thread, and those were probably the initial instructions a long time ago.