I was once told I needed a blood transfusion after internally haemorrhageing and emergency surgery but they had to ask permission at the time because of the AIDS scare in th blood supply. I declined. I also declined the nasty 'iron' concoction they said I had to take instead (or I might die). I did not die. I recovered within a few days. Blood transfusions have always been a con. just like organ transplants our bodies reject foreign tissues and proteins.
I've also heard coconut water can be used as an alternative or clean sea water.