In cases of massive “bleed outs” from trauma or hemorrhage, or for patients with leukemia or other cancers, blood transfusions can be lifesaving.
At the same time, experts say there is remarkably little evidence to show which patients — short of those suddenly losing large amounts of blood — actually benefit from blood transfusions.
These are the points that doctors do not agree with witnesses on and where I would have to draw the line myself. I'm all for any medical advances that allow for less blood to be used during surgery but if a large sudden loss were to occur, there is no substitute for a transfusion. Yes, true, I've heard of blood expanders but they miss the key ingredient that carries oxygen.
Now, some contradictions in their doctrine. Blood fractions are fine but no witness is allowed to give blood so that its fractions can be used for other recipients. Blood recapturing is fine but autologous blood transfusions are not (it must be poured on to the ground).