Berita MMA – June 2022
Transfusion seems to be the immediate and “easiest” solution to treat patients with anaemia, thrombocytopenia, and prolonged coagulation profile. However, by giving patients blood products, are we helping them or are we doing more harm?
Dr Tengku Ahmad Hidayat, our Consultant Internal Medicine Physician & Clinical Haematologist addresses a few areas surrounding this topic.
Types and Preparation of Blood Products
The common types of blood products are whole blood, red blood cells, platelets, and plasma derived products such as fresh frozen plasma and cryoprecipitate. They are prepared via centrifugation/sedimentation or apheresis of whole blood.
Further preparations include:
- Washed blood products
Patient Blood Management (PBM)
PBM involves multidisciplinary strategies to manage anaemia and minimise bleeding and transfusion of blood components. This should be practised perioperatively and can be applied in other practices as well (minimally invasive procedures, chemotherapy, etc).
When And When Not to Transfuse
RBC transfusion is advised in conditions where haemoglobin less than 7 g/dL or haematocrit less than 21% or there are decreased oxygen-carrying capacity or acute loss of more than 20% blood volume.
However, there are exceptions in having a lower threshold for transfusion for example in acute coronary syndromes. Meanwhile the transfusion of plasma products are reserved for patients who are having signs and symptoms of active bleeding and not based on the prolongation for the coagulation times or low fibrinogen levels alone.
Transfusion Reactions and Adverse Effects
- Acute Transfusion Reactions
- Potentially Life-threatening Reactions
- Non-life-threatening Reactions
Delayed Transfusion Reactions
They are defined as reactions in which signs and symptoms present after 24 hours of a transfusion.
Delayed haemolytic transfusion reactions (DHTRs) occur >24 hours after the transfusion, typically due to an anamnestic response to a previously encountered foreign RBC antigen. DHTR symptoms are often mild.
Delayed serologic transfusion reactions (DSTRs) are identical to DHTRs, but the patients are asymptomatic. DSTRs are diagnosed when the transfusion service laboratory detects a new clinically significant antibody on subsequent sample testing by either a positive DAT or a positive antibody screen.
Identifying and Threatening the Underlying Condition
The most important aspect of minimising transfusion is identifying and treating the underlying conditions. Nutritional deficiencies like iron deficiency, anaemia and B12/folate deficiency can be corrected using both oral or parentheral which are very easily accessible.
Other specific causes of anaemia like autoimmune haemolytic anaemia and immune thrombocytopenia can be treated using immunosuppression with immediate results.
Thrombocytopenia and coagulopathy or disseminated intravascular coagulation can be caused by sepsis, infection, and malignancy.
Blood products transfusion, although safe are not without its adverse effects. It is best minimised and avoided to ensure that the patients who really require it will be able to benefit from it. Moreover, we do not want patients who lack the indications for transfusion to experience undesirable side effects.
Options to correct the blood abnormalities without transfusion should be exhausted before resorting to utilizing blood products.
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