My names Mikayla and im 15 years old just recently diagnosed with ms, and i have also done the two rounds of steroids and just finished a round of doing the plasma exchange. For me the didnt do it through a tube in my neck but i had two ivs in each of my arm one to take out the blood and one to put in the blood. the one taking out the blood was a bigger needle then a normal iv and they dont leave that one in overnight how they would probably do with a normal iv because its a steel needle ha so dont worry. and i would drink milk before you got it done because theyre taking out your calcium too so the milk will put it back in the worse that happens though if you dont you just get a little tingling around your mouth and your fingertips. and the process for me took a little over 90 minutes and its not painful at all you cant feel them taking your blood out or anything if they decide to do the ivs in your arms instead they wont let you bend your arm with the big needle in it but you will be able to bend your other arm. Thats about it :) i wouldnt worry about this so far the plasma exchanges have worked for me im going back next week to get another round since my vision is seeming to improve hopefully it works for you too good luck!