The importance of blood transfusion in clinical practice cannot be denied. The benefits of blood and blood products are unique and manifold. However the benefits are not without its accompanying hazards. It is of utmost importance that blood for transfusion is safe with its quality unquestioned. Any compromise on this can lead to serious consequences for the patient. The common errors to watch out for in blood transfusion are transcription errors, labelling errors, incorrect sampling of blood from donor, administering wrong unit of blood to patient and not following proper protocol during transfusion.
Safe Blood Transfusion
For transfusion to be done in a safe manner, the following factors need to be addressed:
Blood should be taken from a healthy donor.
Blood should be checked for infection.
The processing, storage and transportation of the blood to be transfused should follow standardised protocol.
Transfusion to be done only when it is considered absolutely essential.
Blood Transfusion in Anaemia
What is anaemia?
It is a condition in which there is a shortfall of RBC, as a result the oxygen that the RBC delivers to the peripheral tissue is also reduced. Anaemia is measured by haemoglobin level, the haematocrit and the RBC concentration in cells per litre. Generally haemoglobin level is what physicians prefer to find out the severity of anaemia. For practical purposes, the haematocrit concentration is used. The World Health Organization classifies the severity of anaemia according to the following values:
Mild anaemia (9.5-10.9 g/dl)
Moderate anaemia (8-9.4/dl)
Severe (6.5 – 7.9 g/dl)
Indications for Transfusion in Anaemia
Transfusion is considered for pregnant women who display severe anaemia at 36 weeks of gestation.
Anaemia as a result of post partum haemorrhage.
When anaemia presents with chronic infection.
Patient’s failure to respond to oral iron therapy.
When pregnant women exhibit serious health conditions (dyspnea with heart failure), then irrespective of gestational age of foetus, transfusion is carried out.
Blood transfusion is not mandatory for anaemia. To tackle anaemia, the following options can be tried:
Using iron supplements to raise the haemoglobin level. Only in the case of chronic anaemia or when a quick increase in haemoglobin level is vital, transfusion is carried out.
Delivering iron intravenously (IV) can also be considered.
Detecting the shortage of iron and replacing it before surgery is carried out.
Autologous blood transfusion is also an option. Here the blood the patient looses during surgery is reinfused into the patient. It is also known as intraoperative blood salvage.
As already pointed out, the transfusion of blood is not carried out based on the haemoglobin value alone. The transfusion should have an effect towards the betterment of the patient’s lifestyle. The WHO advises transfusion only for patients with haemoglobin ‹ 6.5 g/dl. If the reason for anaemia is only iron deficiency, then transfusion is not done as various other simpler treatment options are available. In elderly patients with severe anaemia, transfusion is recommended especially when patient presents with conditions like angina and congestive heart failure.
Haemolytic anaemia caused by haemolysis also requires transfusion.
Indications for Red Blood Cell Therapy in Anaemia
In anaemic patients, the RBCs do not supply adequate amount of oxygen to the tissues. Therefore the heart pumps harder to meet the oxygen demand. As a result, the heart is the organ which has been put to risk in anaemia.
Whole blood transfusion is rarely carried out. What is usually in practice is the separation and usage of red blood cell units alone so that the other blood components (platelets and plasma) can be used for other purposes. RBC transfusion is also not to be considered when the cause of anaemia is iron deficiency or vitamin B12 or folate deficiency. However iron deficient patients when presented with active bleeding are candidates for RBC transfusion. This is because the main concern now is to stabilize the patient. Once the patient has stabilized the treatment for the bleeding can commence.
The AABB (American Association of Blood Banks) gives guidelines for scenarios when RBC transfusion should be considered:
In the treatment of symptomatic anaemia
Prophylactically in case of life threatening anaemia
In case of haemorrhage to restore the oxygen delivery
In case of exchange transfusion as a result of severe infection
Article by Dr. Shantha Ravisankar,
Chief of Lab Services, Kauvery Hospital, Chennai