Im currently doing my first round of IVIG (day 4 of 5). I wish i had known about hydration because I have the WORST headache right now. but other than that its pretty easy. there are 3 different brands of IVIG so try to get the one that they can put into your body at 400 mL/hr or else you will be at the hospital ALLLLLLL DAY. I had the slow one the first 2 days and that one maxes out at 150 mL/hr i was there for 6 hrs both days. it goes by weight and i had 687 ml of the stuff. try to see if the doctors will let you call ahead too so they can start mixing the IVIG before you get there, it takes an hour and a half to 2 hrs for them to make it and it costs about $10000 per bottle so they dont want any cancellations so a lot of places will only start making it once you get there.