Blood Transfusion

September 6, 2022
by Hannah Farrell

In some circumstances, individuals may require intravenous (IV) infusion of blood, either in its totality or specific constituents. You can read more about what blood is here.

What are the types of blood transfusion and when are they used?

Type of Blood ProductComponentsMethod of ActionIndication
Whole bloodErythrocytes, granulocytes, thrombocytes, and plasma.All components of the blood are provided, thus having multiple actions.Trauma, surgery.
Red blood cellsErythrocytesIncrease the oxygen carrying capacity of the blood.Trauma, surgery, anaemia, haemorrhage, sickle cell anaemia.
Fresh frozen plasma (FFP)Unconcentrated clotting factors, without plateletsCorrects coagulopathy by providing replacement plasma proteins.Active bleeding in the presence of abnormal clotting, reversal of warfarin.
White blood cellsGranulocytesThe most crucial aspect of the human’s immune system.Profound, persistent neutropenia that is unresponsive to antibiotics.
PlateletsThrombocytesStick to the inside of blood vessels, creating a blood clot and preventing blood loss.Thrombocytopenia, malfunctioning platelets, bleeding.
CryoprecipitateConcentrated clotting factors: factor VIII, von Willebrand factor, and fibrinogenBlood loss reduction by helping to slow or stop bleeding by enabling the blood to clot.Haemophilia, von Willebrand disease,
Human albumin solution (HAS)Plasma and albumin.Albumin is a protein which draws interstitial fluid from the tissues and into the blood vessels, thus increasing the oncotic pressure and blood volume (and therefore helping raise blood pressure), and reducing oedema.Acute/sub-acute loss of blood volume (fluid resuscitation), hypoalbuminemia (low blood levels of albumin), sepsis,
Coagulation factorsThese may contain one, or a variety of the clotting factors involved in the clotting cascade.These are vital in the induction of blood clotting.Specific clotting factor deficiencies.
ImmunoglobulinsAvailable as independent products.These replace the absence of antibodies within the body.Antibody deficiency.

Blood Groups – ABO Grouping System

There are four groups of blood categorised according to the antigen (protein) present on the surface of the red blood cells. Each person has only one blood group. Present within the blood plasma are antibodies. These antibodies are proteins which work by recognising foreign antigens; if they identify an antigen which they do not recognise, they will trigger an immune response i.e., if they detect foreign antigens on a red blood cell they will destroy the red blood cell.

Consequently, an individual’s blood group decides their compatibility with other blood groups in terms of receiving a blood transfusion. Equally, the blood group defines how compatible a person’s blood is for donating.

Blood GroupSurface AntigensAntibodiesRecipient Blood Product CompatibilityDonor Blood Product Compatibility
Group AAntigen A onlyAnti-B antibodiesGroup A or O only.Group A or AB.
Group BAntigen B onlyAnti-A antibodiesGroup B or O only.Group B or AB.
Group ABAntigen A and BNeither Anti-A or Anti-B antibodiesUniversal i.e., can receive blood from anyone.Group AB only.
Group ONo antigen is present.Anti-A and Anti-B antibodiesGroup O only.Universal i.e., blood can be given to anyone.

What are the potential complications of blood transfusion?

Whilst blood transfusions are delivered to a patient with the aim of improving their clinical status, as with all medical interventions, they have associated risks with varying degrees of severity.

  • Acute haemolytic reaction (Graft vs Host Disease) – this occurs due to ABO incompatibility i.e., infusion of a blood type which does not match the recipient. The body   detects the donor blood cells as a foreign body, leading to haemolysis. This is a severe, life-threatening reaction. The diagnosis is confirmed through performing a direct antiglobulin test.
  • Transfusion associated circulatory overload – volume overload due to the volume of blood transfused.
  • Transfusion related acute lung injury (TRALI) – antigens present in the donor blood trigger an immune response leading to pulmonary oedema and acute respiratory distress.
  • Infective shock – resulting from bacterial-infected donor blood.
  • Hypocalcaemia – the preservative within the donor blood results in calcium levels to drop.
  • Hyperkalaemia – the transfusion of blood can lead to some red blood cells being damaged and releasing their intracellular potassium, thus raising potassium blood levels.
  • Iron overload
  • Febrile non-haemolytic reaction
  • Transfusion-transmitted infection
  • Severe anaphylaxis
  • Hypothermia – due to the cooled temperature that blood products are stored at.

How are blood products prescribed?

The National Institute for Health and Care Excellence (NICE) has produced guidelines on blood transfusion. Within this guidance, NICE have outlined an algorithm which should be followed by healthcare professionals within the UK. The algorithm outlines several key points:

  • Alternatives for blood transfusion should be considered;
  • The most appropriate blood component/product should be identified;
  • Both written and verbal consent must be obtained by the patient and/or carer, and the process documented within the notes. This involves:
    • Providing written and verbal information covering:
      • Rationale for transfusion
      • Risks and benefits
      • Transfusion process
      • Alternative options available
      • Advising the individual they will no longer be eligible to donate blood

NICE outline the importance of patient safety including the need to closely monitor for acute blood transfusion reactions.

The Infected Blood Inquiry Into The Contaminated Blood Scandal

During the 1970’s and 1980’s in the UK, the NHS treated individuals affected by bleeding disorders with factor concentrate of factor VIII. At the time, factor concentrate was revolutionary in that it meant patients with haemophilia could now receive treatment via injection at home, rather than attending hospital for a blood transfusion.

Factor concentrate was produced by gathering blood from up to 40,000 donors, concentrating it down, and then extracting a specific blood clotting factor. At this time, the donated blood did not routinely undergo heat treatment, and therefore there was a risk of the blood containing an infection. This risk was further significantly increased by the huge numbers of donors required to produce the concentrate; one contaminated donor could infect an entire batch of product. Further associated with the large number of donors required, was that the UK eventually ran low on the number of donors available. At this point, the UK began importing blood from people in America who were paid to donate blood; a large proportion of these donors were prisoners and drug addicts and at higher risk of blood-borne viruses. Consequently, huge numbers of people received blood contaminated with infections such as HIV and hepatitis.

The Blood Safety and Quality Regulations 2005

Since the risks of blood transfusion were learned, laws have been implemented to regulate the handling of blood products and reduce the risks.

The Medicines and Healthcare products Regulatory Agency (MHRA) regulate blood establishments, hospital blood banks, and sites where human blood and its components are collected, tested, and supplied, with intension for transfusion.

Blood establishments include: NHS Blood and Transplant (NHSBT), the Scottish National blood Transfusion Service (SNBTS), the Northern Ireland Blood Transfusion Service (NIBTS), and the Welsh Blood Service (WBS).

All blood must comply with the UK’s blood safety and quality regulations, should the intension be to use it for transfusion.

All serious adverse events or reactions to blood products must be reported to MHRA.

The Joint United Kingdom Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee (JPAC) have released guidelines for blood transfusion services operating in the UK. These guidelines, also known as the “Red Book”, were first introduced in 1990 and offers guidance based on expert opinion and current best practice and outlines set standards which should be met. The guidelines are designed to reflect the Blood Safety and Quality Regulations 2005.

Our Medico-Legal Expert Witnesses in Haematology are able to provide expert advice on all things related to the blood, including blood transfusions and what can go wrong.