FabReads Digest with Clinical Sciences – 005 (Blood Transfusion)

Blood  transfusion is the process of transferring blood or blood components from  one person (the donor) into the  bloodstream of  another person (the recipient).

BLOOD TRANSFUSION.

Blood transfusion is the process of transferring blood or blood components from  one person (the donor) into the bloodstream of  another person (the recipient). Transfusion is done as a  life-saving procedure  to  replace blood cells or blood products lost through bleeding.

CONDITIONS WHEN BLOOD TRANSFUSION IS NECESSARY

Blood transfusion is essential in the following conditions:

1. Anemia
2. Hemorrhage
3. Trauma
4. Burns
5. Surgery

PRECAUTIONS TO BE TAKEN BEFORE THE TRANSFUSION OF BLOOD

1. Donor must be healthy, without any diseases like: a. Sexually transmitted diseases such as syphilis b. Diseases caused by  virus like hepatitis,  AIDS, etc.
2. Only compatible blood must be transfused
3. Both matching and cross-matching must be done
4. Rh compatibility must be confirmed.

HAZARDS OF BLOOD TRANSFUSION

Hazards of blood transfusion are of four types:

1. Reactions due to mismatched (incompatible) blood transfusion – transfusion reactions.
2. Reactions due to massive blood transfusion
3. Reactions due to  faulty  techniques during blood transfusion
4. Transmission of infections.

REACTIONS DUE TO MASSIVE BLOOD TRANSFUSION

Massive transfusion is the transfusion  of blood  equivalent or more than the patient’s own blood volume. It leads to

• Circulatory  shock, particularly  in patients suffering from  chronic  anemia, cardiac diseases or renal diseases ii. Hyperkalemia  due to increased  potassium concentration in stored blood.
• Hypocalcemia  leading  to tetany due to massive transfusion of citrated blood.
• Hemosiderosis (increased  deposition of  ion in the form of  hemosiderin,  in organs  such as endocrine glands,  heart and  liver) due to  iron overload after repeated transfusions.

REACTIONS DUE TO FAULTY TECHNIQUES DURING BLOOD TRANSFUSION

Faulty techniques adapted during blood transfusion leads to:

1. Thrombophlebitis (inflammation of vein, associa ted with formation of thrombus).
2. Air embolism (obstruction of blood vessel due to entrance of air into the bloodstream).

TRANSMISSION OF INFECTIONS

Blood transfusion without precaution leads to transmission of blood-borne infections such as:

1. HIV
2. Hepatitis B and  A
3. Glandular fever  or infectious mononucleosis (acute infectious disease caused by  EpsteinBarr virus  and characterized by fever, swollen lymph nodes, sore throat and abnormal lymphocytes)
4. Herpes (viral disease with eruption of  small blister-like vesicles on skin or  membranes)
5. Bacterial infections.

CONDITIONS WHICH NEED EXCHANGE TRANSFUSION

1. Hemolytic disease of  the newborn (erythroblastosis fetalis).
2. Severe sickle cell anemia.
3. Severe polycythemia  (replacement  with saline, plasma or albumin).
4. Toxicity of certain drugs.
5. Severe  jaundice in  newborn babies, which does not respond  to  ultraviolet  light therapy.  Normally, neona tal jaundice is treated by exposure to ultraviolet rays. It  breaks down the bilirubin  which is excreted by liver.