A certain number of these cells are needed for the body to function. Bleeding due to trauma, surgery, or disease may cause a low red blood cell count. White blood cells fight infections by destroying bacteria, viruses, and other germs. White blood cell transfusions are rarely given. They are usually reserved for children who have a low white cell count and severe infection that is not responsive to antibiotic therapy.
Platelets help control bleeding by covering blood vessels opened by injury or surgery.
The body may not be able to make enough platelets because of bone marrow disorders, increased destruction of platelets, or medications such as chemotherapy. Platelets may be transfused before an invasive procedure that may cause a child with a low platelet count to bleed. Plasma carries the blood cells throughout the body and contains proteins, vitamins, and minerals. Some of the proteins help the blood to clot. Plasma or fresh frozen plasma can be transfused in children who have a severe deficiency of certain clotting components of the blood.