i am glad you chimed in on this thread,what do you know about plasma expanders,if you dont mind
me and rockedupmutha were talking the other day and realized,niether of us know anything about them
and since this thread is already about vaso-dilators we might as well kick it up a notch 
To be very honest I don't know much about Plasma Expanders. I've read about them as PRO's may use them from time to time but it's very tricky and has to do with i.v.'s and what not...
Here's another tip. Advair. Advair is an inhaled medication popular with asthmatics. I don't have asthma but I have a 'carterage' in my gym bag. You can get it in a powerded form and you inhale it. An inhale or two of Advair...kind of like albuterol before delts or arms...fugheddaboutit.
Also...before a show...check this out. Before a show...right before prejudging, whip out a BOTTLE of KoolWhip and suck out the nitrous GAS. YES, just as you did in highschool to feel high and giddy.
Hit the KoolWhip bottle for a big hit and then train...after the lightheadedness goes away. After your warmup set you will be aching.