Blood Transfusion

Introduction to Blood Transfusion

Blood transfusion is the administration of blood for therapy.
It is potentially hazardous: blood should be given only if the dangers of not transfusing outweigh those of transfusion.
Indication(s) must be clearly established.
Transfusion of whole blood or red cell
concentrates is important in the treatment of acute blood loss and of anaemia.
Red cells can be stored at 4°C for 5 weeks in media that are specially designed to maintain the physical and biochemical integrity of the erythrocytes and which maintain their viability after transfusion.
Citrate Phosphate Dextrose with Adenine (CPDA) is commonly used for collections of whole blood.
The use of whole blood as a therapeutic agent has been almost completely replaced by the use of blood fractions.

Types of blood transfusion

  1. Autologous blood transfusion: Transfusion of the patient’s own blood to him/her . This is the safest blood for patients. The three main techniques of autologous transfusion are:
    • Pre-deposit autologous transfusion
    • Immediate pre-operative phlebotomy with haemodilution.
    • Interoperative and postoperative blood salvage
  2. Allogenic blood transfusion: homologous, or allogenic blood transfusions involves someone collecting and infusing the blood of a compatible donor into him/herself.
  3. Heterologous blood transfusions are those that involve someone infusing blood and its components from a different species.
  4. Exchange transfusion: To remove deleterious material from the blood, for example, in severe jaundice resulting from haemolytic disease of the newborn

Alternatives to red cell transfusion:

  • Perfluorochemicals such as Fluosol-DA Polymerised haemoglobin solutions with good intravascular recovery

Indications for blood transfusion

  1. Symptomatic anaemias:
    • Recurrent haemorrhage
    • Haemolysis
    • Bone stem cell failure
    • Pure red cell aplasia
    • Severe anaemia of chronic disorders
    • Haematological malignancies (e.g. leukaemia, lymphoma)
    • Chemotherapy complicated by anaemia
  2. In neonates:
    • Severe acute haemorrhage
    • Haemolytic disease of the new born Septicaemia
    • Prematurity bleeding disorders:
      • Congenital e.g. haemophilia
      • Acquired e.g. disseminated intravascular coagulopathy
  3. Prevention or treatment of shock:
    1. Clinical situations in which there is need to restore and/or maintain circulatory volume e.g. trauma, haemorrhage
  4. To maintain the circulation (as in extracorporeal or cardiac by-pass shunts).

Whole blood preparations: Should be limited to correction or prevention of hypovolaemia in patients with severe acute blood loss
Fresh Blood: Justified by the recognition that there is a relatively rapid loss of platelets, leucocytes and some coagulation factors with liquid storage.
There is also progressive increase in the levels of undesirable products such as potassium, ammonia, and hydrogen ions.

Erythrocyte preparations

Four types are in common use:

  1. Packed red blood cells
  2. Washed red blood cells
  3. Leucocyte-reduced red blood cells
  4. Frozen red blood cells

Washed red blood cells:

This is obtained from liquid-stored blood by saline washing using a continuous-flow cell separator or from frozen erythrocytes extensively washed to remove the cytoprotective agents.

Leucocyte-reduced red blood cells:

Best prepared by passing whole blood or packed cells through specifically designed filters. Three main reasons for the use of leucocyte reduced red blood cells:

  1. To prevent non-haemolytic febrile reactions to white cell and platelet antibodies in recipients exposed to previous transfusions or pregnancies
  2. To prevent sensitization of patients with aplastic anaemia who may be candidates for bone marrow transplantation
  3. To minimize risk of transmission of viruses such as HIV or cytomegalovirus

Transfusion therapy

Informed consent should be obtained from patients except in life-threatening emergencies The risks and benefits of the proposed transfusion therapy should be discussed with the patient and documented in the patient’s medical records.

Blood for emergencies:

There may be no time available to type, select and cross-match compatible blood. This is a rare occurrence, except for:

    • Trauma
    • Unexpected intra-operative haemorrhage
    • Massive gastro-intestinal bleeding
    • Ruptured aneurysm

Uncross-matched or partially cross-matched blood is administered; routine cross-match should be carried out retrospectively to identify any incompatibility

Complications of blood transfusion

A. Immunological:

  • Sensitization to red cell antigens
  • Haemolytic transfusion reactions
    • Immediate
    • Delayed
  • Reactions due to white cell and platelet antibodies
    • Febrile transfusion reactions
    • Post-transfusion purpura
  • Reactions due to white cell and plasma protein antibodies

B. Non-immunological:

  • Transmission of disease
  • Reactions due to bacteria and bacterial pyrogens
  • Circulatory overload
  • Thrombophlebitis
  • Air embolism
  • Transfusion haemosiderosis
  • Complications of massive transfusion

Tests of Compatibility

A minimum of three major procedures must be carried out:

  1. Determine the recipient’s ABO and Rhesus groups
  2. Select compatible donor blood
  3. Cross-match donor cells against recipient’s serum

Donor blood should be screened for infective agents: HIV, hepatitis B, and C viruses

Other investigations

  • Haemoglobin concentration, haematocrit
  • Red cell indices: MCH, MCV, MCHC
  • Total leucocyte and differential counts
  • Reticulocyte count
  • Erythrocyte sedimentation rate
  • Platelet count

Treatment objectives

  • To raise haemoglobin concentration and other blood parameters to normal levels
  • To prevent blood transfusion complications

Non-drug treatment

  • Transfusion of red blood cells, platelet concentrates or platelet rich plasma as required
  • Provision of fresh frozen plasma or other blood products as necessary

Drug treatment

  • Furosemide 40 mg on administration of one unit of blood
  • In the event of transfusion reactions, stop the transfusion immediately and administer the following: Promethazine 25 mg intramuscularly or intravenously
  • Epinephrine 0.5 mL of 1:1000 solutions to be administered subcutaneously
  • Hydrocortisone sodium succinate 100 mg injection intravenously

Supportive measures

  • Appropriate nutrition
  • Adequate hydration

Notable adverse drug reactions, caution

  • Furosemide: dehydration and hypersensitivity
  • Promethazine: drowsiness, hypersensitivity

Prevention

  • Avoid/prevent accidents
  • Prompt treatment of illnesses that could be complicated by anaemia
  • Regular medical check-ups