Blood transfusion

Blood transfusion- what is it and when is it indicated?

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Blood transfusion- Indications, Procedure, Cost, and Problems 

What is Blood Transfusion? Blood transfusion refers to transferring blood or its components into a human recipient’s vein for therapeutic purposes to replace the blood or compensate for those deficient blood components. It can be a lifesaving measure to replace the blood lost during surgery, severe traumatic injury, or burns. It can also be useful when the body cannot produce enough blood components or if the blood components produced are defective. Blood transfusion For example, in severe anemia, when the Haemoglobin levels fall below 7gm per decilitre, blood transfusion, either whole blood transfusion or packed RBC transfusion, is advised. Similarly, in thalassemia patients, where there is defective hemoglobin chain synthesis, and as a result, there is hemolytic anemia, repeated blood transfusions are advised to prevent the delay in growth the predisposition to infections. The blood required is obtained from a donor or a blood bank. Thus, blood banks are responsible for collecting, testing, and storing blood. Normally, in most surgical and minor surgical procedures, the need for blood transfusion does not arise. One of the major focuses of modern-day surgery is to reduce blood loss and maintain the homeostasis of the body’s organ systems. However, surgical patients might require a blood transfusion, and it is better to keep the possibility in mind before consenting for surgery and planning for post-operative care. The need and indication and the risks of transfusion must be discussed with the treating physician. It is always advisable to begin the decision-making process as early as possible since there are time limitations and health restrictions.

Blood transfusion Types

The types of blood transfusion depend upon the donor, who has donated blood to the blood bank. By far, volunteers’ blood donations are the most common type of blood donations available in the blood bank. The blood from such donors is usually readily available and, with proper screening, has little risk of adverse outcomes. However, the likelihood of contracting infections, such as Hepatitis B and HIV, remains if there is improper testing. Autologous blood transfusion refers to the transfusion of one’s own blood. It is naturally only possible in pre-planned (elective) surgical procedures and needs to fulfill certain eligibility criteria. It is the safest method with practically no risks. Directed donor blood transfusion allows the patient to receive blood from family members or friends (known donors). However, it needs to be collected several days before the transfusion’s actual need to ensure testing and screening. However, the protocols for both blood donation and transfusion are specific for the respective hospitals. As mentioned above, blood transfusion is a life-saving procedure. However, one may refuse to provide consent for the same, leading to disastrous complications and even death. However, doctors may provide emergency blood transfusion to save the recipient’s life in case of emergencies.

Prerequisites: Blood transfusion

Before transfusing the blood, the healthcare provider ensures re-confirmation of the identity, the blood group, and the amount to ensure that blood is given to the correct patient. However, if during transfusion, one has symptoms of breathlessness (dyspnea) or itching and fever or chills (blood transfusion reaction), the healthcare provider must be alerted immediately. As mentioned above, blood source can be Autologous (one’s own) or Donor (someone else’s) blood. Autologous blood transfusion is further divided into Preoperative, Intra-operative, and Post-operative donation. Hemodilution is another method in which some blood is drawn during the surgery and is replaced with IV fluids. Later, after the surgery, the blood is filtered and returned to the body. However, large amounts of blood cannot be drawn by this method. Plasmapheresis: It is another variant in which platelets and plasma are withdrawn before surgery and returned to the body when there is a need to stop bleeding. However, it has limited applications. The second type is the donor blood, which can be volunteering-based (blood banks) or by designated donors (family and friends). The blood is screened for infectious agents and other noxious substances. However, the risk of infection remains, albeit minuscule.

Blood and its components:

A 60 kg human has around 5 liters of blood, which constitutes about 8% of the adult human body weight. Blood is a fluid connective tissue. It is composed of plasma (55%) and formed elements (45%). The formed elements include red blood cells, white blood cells, platelets, proteins, and coagulation factors. There are various blood groups. The blood group is determined by antigens’ presence (specialized proteins) on the red blood cells’ surface. Thus, a person with blood group A has A antigen, a person with blood group B has B antigen, and a person with blood group AB has both, A and B antigens on the surface of the red blood cells. Similarly, a person with O blood group has neither A nor B antigens on its surface. There is a presence of corresponding antibodies in the plasma of the patients. Thus, a person with blood group A will have an anti-B antibody (antibody directed against B antigen, since it is not present in the person). Similarly, a person with blood group B will have an anti-A antibody. A person with blood group AB will have no antibodies. Lastly, a person with blood group O will have both, A and B antibodies (since both the antigens are absent on the red blood cells). Another factor is the Rh factor, also referred to as the D antigen. Patients with D antigen are Rh-positive, while those who do not have the antigen are Rh-negative. Thus, an Rh-positive person can receive blood from both Rh-positive and Rh-negative persons. However, Rh-negative persons should only receive blood, which is Rh-negative. (Rh-negative blood is to be used for emergencies when there is no time to test a person’s Rh type)


It is clear then that a person with blood group AB positive would be the universal recipient (since he has no antibodies in his plasma, and hence he can receive blood from any blood group person) The person with O negative would also be the universal donor since his RBCs have no antigens on its surface. They can be transfused into another person without the fear of an antigen-antibody reaction in the recipient. There may be whole blood transfusion, or only a part may be transfused, such as platelets (in dengue) or RBCs (in severe anemia).

Red Blood Cell Transfusions

RBCs or Red blood cells are the most commonly transfused component of the blood. RBCs are responsible for carrying oxygen from the lungs to the tissues and carrying carbon-dioxide back from the tissues to the lungs for expiration. RBC transfusion is indicated after surgery, severe injury, hemorrhage, or anemia. Anaemia refers to the decrease in the oxygen-carrying capacity of the blood due to a decrease in RBC number or decrease in hemoglobin concentration or both, below the normal levels for that particular age and sex. (Haemoglobin in the RBCs is responsible for oxygen transport and gaseous exchange in the body).

Platelets and Clotting Factors transfusion:

Both the products are useful in hemostasis to stop the bleeding (internal or external) and prevent hypovolemia and shock. They are also indicated in conditions where the body is unable to make sufficient platelets or clotting factors. E.g., In hemophilia, which is an X-linked recessive disorder, clotting factors are absent. As a result, there is excessive bleeding on minor trauma. There can be spontaneous internal hemorrhage in joints, knees, etc. Another disease in which it is indicated is thrombocytopenia, where there is a deficiency of platelets.

Plasma Transfusion:

As mentioned above, plasma is the liquid part of the blood. It is composed mainly of water, proteins, clotting factors, and nutrients such as glucose, vitamins, and minerals. It is generally indicated in patients with severe burns (who have extensive loss of plasma), chronic liver failure, or a severe sepsis infection.

What to expect: Blood transfusion

Before Transfusion:

You would be asked if you had something to eat before you came for transfusion. If not, biscuits and juice would be provided to maintain the blood sugar level and prevent a syncopal attack.
The technician will prick one’s finger, and the blood drops are placed on the slide. Alternatively, blood from one of the veins is dropped, and with the help of appropriate reagents, the blood group is determined, whether A, B, AB, or O, and whether it is Rh-positive or negative.
Only compatible blood is provided for transfusion to prevent the risk of antigen-antibody reaction and hemolysis. Also, to prevent allergic reactions, which may be genetically determined and hard to know beforehand, medicines may be prescribed to prevent such reactions.

During Transfusion:

A blood transfusion may occur in an in-patient ward, where the patient is admitted or during surgery in the Operation Theatre Complex or the emergency rooms. An appropriately sized needle is used to insert an IV cannula or an IV line into the blood vessels, and the other end is attached to a blood bag, from which the blood is transfused. It usually takes between 1 to 4 hours for transfusion. However, the time duration may vary depending upon the units of blood transfused and the components transfused. Throughout the transfusion, the vital signs are monitored, especially to watch out for signs of allergic reactions.

After Transfusion

Post-transfusion, vital signs are checked, such as temperature, blood pressure, heart rate, and oxygen saturation. The IV cannula is taken out. There may be bruising at the site of cannulation due to thrombophlebitis and some edema. However, it resolves within a day or two.

Blood transfusion: Allergic Reactions and Transfusion-associated complications

The majority of blood transfusions do not have any adverse effects. However, mild edema and pain at the injection site to more severe symptoms like systemic anaphylaxis can ensue.

Allergic Reactions:

They may occur even with the right type of matching blood transfusion.
  • They may be mild or severe, and the symptoms include:
  • Tachycardia (increase in heart rate) and palpitations
  • Anxiety and perspiration
  • Cold, clammy skin
  • Anxiety
  • Breathing difficulties (dyspnoea)
  • Nausea and vomiting
The transfusion stopped at the first sign of these allergic transfusion reactions. The severity of the reaction is assessed, and depending upon the need for treatment, transfusion may be restarted or aborted.

Viruses and Infectious Diseases:

The screening of blood is done to prevent the following diseases. The risk of HIV infection via blood transfusion is 1 in 2 million, much lower than road traffic accidents and other morbidity causes. The risk of Hepatitis B infection is 1 in 2,00,000, while Hepatitis C infection is 1 in 2 million. Variant Creutzfeldt-Jacod Disease, earlier referred to as Kuru disease, is a prion mediated fatal brain disorder. The possibility of it remains low, via a blood transfusion, but is a documented risk.


Within a day or two of blood transfusion, one may develop a fever, which is the body’s physiologic response to the transfused White blood cells. However, it resolves over a period of 1-2 days or with over-the-counter NSAIDs such as paracetamol and diclofenac. Many times, WBCs are centrifuged and removed and not transfused. This makes the chances of a fever developing less likely.

Iron overload:

Repeated blood transfusions may lead to an iron buildup in the blood. This is especially true concerning hematological disorders like Beta-thalassemia. It can lead to iron overload(siderosis) and iron deposition into the liver, heart, and other vital internal viscera. Iron chelation therapy reduces the gut’s iron absorption in the form of desferrioxamine or intake with vitamin C. This helps to maintain the blood iron levels at a normal range.

Risks and Complications: Blood transfusion

Transfusion Associated Acute Lung Injury (TRALI):

Normally, during a blood transfusion, the vital parameters such as heart rate, blood pressure, and respiratory rate are monitored. In some patients, post-transfusion, there can be difficulty in breathing due to lung damage. However, it may be transient dyspnea, and the majority of patients recover. In 5-25% of those who develop symptoms, the damage may severely cause significant lung injury and death. It is more common with severely immunocompromised patients. It is postulated that plasma from women who have been pregnant might be responsible for antibodies that damage the lungs and disrupt respiration. Thus, male and female plasma is now being used differently in different centers.

Acute Immune Haemolytic Reaction:

This is a result of mismatched blood transfusion. As a result, the body’s host defense mechanisms attack and destroy the transfused RBCs. Hemolysis and hemoglobinuria, which, when deposited in the kidney, leads to acute tubular necrosis and acute renal failure. The symptoms include: Fever with chills Loin pain or pack pain Dark or cola-colored urine. It is an acute reaction, and blood transfusion is stopped at the first sign of acute hemolytic reaction.

Delayed hemolytic reaction:

As is evident in the name, in contrast to acute hemolytic reaction, the red blood cells are destroyed insidiously over time in delayed hemolytic reactions. Both acute and chronic reactions are common in patients who have had a previous blood transfusion history.

Graft versus host disease:

It is a hypersensitivity reaction in which the white blood cells from the donor plasma attack the antigens present in the recipient’s tissues and organs. Immunosuppression is a major risk factor for developing graft versus host disease. The symptoms generally start within a month of transfusion and include fever and body rash. To minimize the risk of developing GVHD, only RBCs are transfused, while WBCs are centrifuged and removed.

Alternatives to Blood Transfusions:

There are no alternatives to blood; however, some recombinant substances, which mimic the endogenous substances, have been produced, making red blood cells. For example, in patients with chronic kidney disease, recombinant erythropoietin is administered. It stimulates the bone marrow to produce more red blood cells, thus requiring fewer transfusions. With minimally invasive surgeries, such as laparoscopic and endoscopic surgeries, the amount of blood loss is minimized. Also, with optimum peri-operative and post-operative care, the risk of infections is reduced, and blood transfusions are seldom required.   Refer to other articles:  

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