The whole process is incredibly expensive and wasteful, because of all the materials that need replacing between each patient. Totally worth it though, for the lives it saves and improves. (A lot of it goes towards cancer treatments.) The thing that terrifies me is getting air bubbles pushed back into my veins. The machines have two air bubble sensors. But I can see them show up in the tubes occasionally, and it freaks me the h*ck out. Oh, and getting burst veins/bruises sucks. One time the nurse didn't put the needle in far enough, so that plus the high blood pressure from the cuff made my blood shoot straight up in the air like something out of a cartoon.