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Multiple Transfusions

You are here : Home/ Blood Bank Zone/ Blood Transfusion in Clinical Practice / 8. Multiple Transfusions

8. Multiple Transfusions

Chronic/multiple transfusions may be a life long therapeutic requirement in many conditions such as chronic anemic states, malignant diseases, chronic renal insufficiency, etc.

Indications

A chronic anaemic state is the end result of a wide range of illnesses. Following is the list of some important clinical conditions requiring multiple transfusions.

Guidelines for assessing requirement of transfusion

Assessing transfusion requirements are based on I-Ib/Hct value of the patient, functional capacity and symptomatology. This requires a complete physical examination and at times physiological testhig Physical examination should include cardiovascular and respiratory evaluation. A special note of splenomegaly should be made.

Guidelines for assessing transfusion requirement

Average Hb level g/dl	Probability of Physiological improvement of oxygen carrying capacity	Transfusion strategy
10 or more	very low	Avoid
8-10	low	Avoid, transfuse only if demonstrably better after transfusion trial
6-8	moderate	Try to avoid if a slow fall in I-lb
6 or less	high	Frequently requires transfusion

Conditions requiring multiple transfusions :

1. Hypoplastic or aplastic anaemia
2. Myelodysplastic syndrome
3. Anaemia of chronic disorders e.g.
* Renal insufficiency
* Hepatic failure
* Endocrine failure
* Malignant tumours
4.Haemolytic anaemias
Thalassaemia. major
Sickle cell anaemia
Autoimrnune haemolytic anaemia (AIHA)
paroxymal nocturnal haemoglobinuria
5. Anaemia due to chronic blood loss
a. Chronic gastrointestinal blood loss
b. Chronic uterine blood loss
Transfusion schedules

Red cell concentrates are preferred to whole blood in transfusing patients with chronic severe anaemia. Transfusions should be scheduled at regular intervals based on the patients requirement. Most children with congenital anaemia such as thalassaemia major are on high transfusion regime (maintaining Hb\> lOg/dI) to enable normal growth and development.

Some physicians advocate a super-transfusion regime in these children to maintain Hb at 12g/dl. This completely suppress erythropoiesis and abolishes the undesirable effects on bone, liver and spleen. Moreover it prevents increased iron absorption from the gut. Usual volume transfused is 10-20 mI/kg body weight.

In general, adults with total failure of red cell production (e.g. aplastic anaemia) require 2 units of red cells every 2 weeks to maintain the desired Hb level. In the absence of blood loss, alloimmunization or other causes of insufficient transfusion, the required intervals between 2 transfusions is 2-4 weeks.

For regular red cell transfusion, it is preferrable to use leucocyte-depleted red cells to minimise non-haemolytic transfusion reactions. Red cells in CPDA-1 upto 7 day old are satisfactory for transfusion.

Laboratory aspects

Red cells should of the same ABO & Rh(D) group and should be crossmatched using saline, albumin/ enzyme and AHG techniques.

In case a patient develops alloantibodies against red cells antigens, antibodies should be identified and compatible blood should be provided.

Extended typing of red cells for antigens of Rh system and for the other important antigens Kell, S, Kidd and Duffy system is carried out in some centres. Although the practice of extended pretransfusion typing has a rationale, it is infrequently of major help in identification of alloantibodies.

In children, red cell less than 5 days old should be used. The volume to be transfused can be calculated from the formula:
V = W(PCV1-PCVO), where
V = Value of red cells required (ml)
Wt = weight of the child (kg)
PCV = Desired PCV (packed cell volume / haernatocrit)
PCVo=lnitial PCV

Example : Volume of red cells required for a child of 10 kg with a PCV of 10 which is desired to be raised to 30 is calculated as follows:
V = 10 x (30-10)
= 10 x 20
= 200 ml

Thus 200 ml of packed red cells are required for this child. (Each unit of packed cells contains 180 ml of red cells). Approximately 1 unit of red cell raises the Hb volume by 1-1.5 gm/dl, therefore, number of units to be transfused should be calculated accordingly.

Neocytes

Recently transfusion of young red blood cells (neocytes) has been advocated. These can be collected with the help of a cell separator. The mean age of neocytes is 12 day and therefore their life expectancy is almost twice that of conventionally collected red cells.

These cells offer the following advantages:
1. Interval between transfusions can be increased twofold.
2. Lesser amount of red cells are needed.
3. Reduced allimmunization to platelets or leucocytes as neocyte preparations are almost free of these elements.
4. Iron overload is less due to lower transfusion requirements.

Inefficient transfusions

Transfusion requirement above the level of 2 units every 2 weeks in an adult suggest inefficiency of transfusion. The possibility of occult alloimmunization to red cell antigen with increased rate of destruction of red cells should be considered in such patients.

Other possibilities that should be excluded are :
1. Presence of autoimmune haemolytic anaemia of the warm antibody type.
2. Administration of blood nearing its outdating.
3. Occult or overt blood loss from GIT or other sites.
4. Non-immunological mechanism of haemolysis such as secondary to splenic enlargement.

Long term effects of multiple transfusions

Besides the risks such as acute haemolytic reactions, transfusion of infected blood and circulatory overload, the real problem in multiple transfusion is the long term efforts.

Some of the long term problems of multiple transfusion are
1. Iron overloading
2. Sensitization to leucocyte or plasma antigen
3. Red cell alloimmunization
4. Risk of transfusion transmitted diseases

Iron overload

Multiple transfusions result in iron overload as nearly 160 mg of iron accumulates with each unit of blood. The excretion of iron by the body is limited to about 1mg/day. Thus iron continues to accumulate in the body mainly in the recticuloendothelial system and in tissues such as heart, liver, pancreas and other endocrine glands and the gonads, resulting in fibrosis and organ dysfunction. These may result in diabetes mellitus, hepatic insufficiency and endocrine disturbances. The most serious complications are bizare atrial and ventricular arrhythmias, and cardiac failure.

The serum ferritin concentration shows a linear relationship with the number of transfusions and is used to assess the iron stores in the body.

Use of iron chelation therepy

Desferrioximine chelates iron and the complex is excreted via the urine. Excess iron can be removed by giving desferrioxamine by constant subcutaneous injection with the help of infusion pump. The procedure is painful and requires good deal of motivation for the children and parents. An oral iron chelating agent Li is undergoing therapeutic trial.

Sensitization of leucocyte or plasma antigens

A high proportion of multitransfused patients eventually develop allergic or anaphylactic reactions due to the antigenic material of donor leucocytes. The majority of multitransfused patients have lILA antibodies, which cause recurrent febrile non-haemolytic reactions after blood transfusion. These reactions can be avoided by use of leucodepleted blood prepared by filtration.

Use of blood filter has also been found to be useful in preventing the alloimmunization to leucocytes or lILA antigens.

Red cell alloimmunization

With the increasing transfusion practice, a greater incidence of single and multiple red cell antibodies has been observed in transfusion recipients. Multitransfused patients have a risk of 6-30% of developing red cell alloantibodies.

These patients who develop alloantibodies do so relatively early in the transfusion programme. Considering the cost and time involved in screening all patients, the usual policy is to transfuse ABO & Rh compatible blood and match more specifically only when the antibodies appear.

Risk of transfusion transmitted diseases

Besides the long term effects of regular multiple transfusions, the patients on multiple transfusions are also exposed to a much higher risk of acquiring transfusion-transmitted diseases such as HIV, HBV, HCV, etc. due to increased exposure to number of different donors.

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