NoBlood

Hi , does anyone know how low of an HB count is considered Life Threatening in Children/Teens, if possible with a Internet link? Our Doctor (recommended by the Liason committee) claims that an HB under 6 is life threatening, he also doesnt believe in EPO. Our son has Leukemia / ALL, and was forced blood against his wishes. His HB was at 5,1 / Heartbeat 120 / Platelets over 100,000 at the time he had no infection. He was still able to go to the restroom, was up and around, still eating(alot), and he could still carry a conversation. I should add that this is a doctor in Germany and in Germany parents have no real legal rights to minors that are in hospital care. We try to work together to a certain degree...Why do doctors use the magical number (HB) 7 when they start giving blood transfusions, to nonwitness children? It would be really nice if someone could help me out. Thank you!