General Meanings:
In general, to receive the blood transfusion indicates the new friendship, relationships or the help that the dreamer will receive from someone.
If the dreamer was the one who gave the blood transfusion to someone else, it also could mean a new relationship to a certain person or the dreamer will be the one who will give a hand when somebody will need it.
when someone dreamed of receiving blood transfusion, he/she is going to receive new life, strength, financial level/strength, position, help etc