Definition of massive transfusion of packed RBC:
a) Transfusion of more than 1 unit of PRBC per hour
b) Transfusion of more than 4 units of PRBC in 1 hour
c) Transfusion of more than 10 units of PRBC in 24 hours
d) Transfusion of more than 20 units of PRBC in 48 hours