Certain precautions and guidelines must be adhered to in blood transfusion to ensure the safety of the procedure. The steps involved in obtaining and checking donor blood for transfusion are described below.

• The donor is asked to complete a questionnaire detailing any history of infectious diseases and other medical issues before they are allowed to donate blood for transfusion.
• The donor’s hemoglobin level is checked.
• Once collected, the blood is examined and screened for possible infectious agents such as HIV and hepatitis.
• The blood from the donor is cross matched with the patient’s blood sample to check it is compatible. Blood group is determined by the antigen profile of an individuals’ red blood cells. The most important antigens in blood typing are the ABO and Rh antigens. Every individual has an ABO blood type (blood group A, B, AB, or O), which means their red blood cells may display antigen A, antigen B, both antigens, or neither antigen. Each person is also either positive or negative for the Rh antigen. Overall, these antigens can combine to give eight possible blood types.
• The patient is only considered for transfusion if they really stand to benefit from the procedure. A complete blood count is performed to check levels of the various blood components including red blood cells, white blood cells, and platelets. Coagulation (clotting) tests are also performed.
• The blood is transfused through tubing that is connected to a needle or catheter supplying the vein.
• The amount of blood transfused depends on the individual patient’s needs.
• During blood transfusion, vital signs such as temperature, heart rate, and blood pressure are carefully monitored
• Some patients may get a sudden fever during or within 24 hours of the transfusion, which may be relieved with acetaminophen or paracetamol. This fever is a common reaction to the white blood cells present in donated blood.