Let’s share a scenario. A person is anemic with a Hb of 9 gm/dl and brought in for a surgical procedure. The doctors agree that the chances of bleeding are low and yet to be on a safer side they request for a unit of blood to be kept ready. They proceed with the surgery and fortunately the patient did not need any blood. Now, the patient is brought back to recover and doctor comes to see the patient during rounds. The doctor is informed that there is still a unit of blood crossmatched for this patient available - which if unused will need to be discarded. The doctor has two options at this point in time:
- Since the patient is surely anemic, the doctor orders for the blood unit to be transfused. Why waste the precious unit of blood?
- The doctor refuses to transfuse and emphases that unless absolutely unavoidable the patient must not be transfused.
Pause and think what would you choose?
More often than not, the first choice is made. Many people transfuse patients preemptively. While wastage of blood is a big issue in itself, the immunological impact of a blood transfusion on a recipient is underestimated and not widely appreciated.
Whenever a person receives any tissue from a foreign source, the body develops antibodies to the antigens of the donor. On receiving blood for the first time, since there are no pre-existing antibodies, there is no immediate complication. But, should the person need blood products in future or if the person is a potential donor or recipient of hematopoietic stem cell or solid organ transplantation in future, there is a risk of having ready antibodies against the donor’s tissue which can cause complications ranging from destruction of donor tissues, rejection of the transplanted tissue and consequently even death. A seemingly harmless transfusion received years back has the potential to wreak havoc in the person’s life.
As science has progressed, and our ability to connect the dots has increased, it is very evident that no allogeneic transfusion is safe. Each transfusion from an unknown person is associated with risks ranging from the risk of acquiring infections to complications associated with the immune system. As we make progress in blood transfusion medicine, there is significant progress on both arms - the one which seeks to make transfusions safer and the one which seeks to reduce the need for allogenic blood transfusions(blood transfusions from donor’s blood). The sheer complexity involved in reducing the risk of complications from allogenic blood and the associated costs all point towards the need for greater adoption of relatively simpler strategies to minimise transfusions.
For a while it was believed that filtering blood products before transfusion can protect the recipient from getting antibodies (allo-immunisation). However randomised controlled trials done with cardiac surgery patients, those who are potential candidates for renal transplants and surgery patients have shown the futility of using expensive blood filtration techniques. At the same time, the debate around the cost-benefit of using techniques like nucleic acid amplification test to reduce the risk of exposure to infections continues to rage.
There are several centres which do elective surgeries like cardiac surgeries which have started routinely using several rounds of autologous blood collection. Infact patients who receive these “bloodless” surgeries tend to recover faster and have smaller hospitalisation duration. Autologous blood collection is nothing but the person giving blood at an interval of 1 weeks upto 4 weeks before their surgery for the same blood to be transfused back when needed. Supplementation given both through injections, syrups and tablets ensure that the patient recovers both quantitatively and qualitatively even after donating blood quickly before the surgery. All units can be transfused safely at the time of surgery, thereby reducing, if not eliminating, the need for blood from other donors. Several patients like those who are undergoing hemodialysis has switched to growth factors like erythropoietin rather than get blood transfusions. These synthetically manufactured growth factors contribute to rapid production of red cells by the donor’s own marrow. Even simple techniques like fighting anemia in the general population by iron fortification and supplementation may drastically reduce the need to transfuse blood.
The safest strategy is to try and avoid use of donor’s blood as far as possible. While it is becoming clear that eventually the awareness around harm done to the patients with blood transfusions will increase and the health systems will employ means to minimise allogenic blood transfusions as a standard practice, until that happens, patients must also start asking their doctors if there is a way to avoid blood transfusions.
For the society in general there is another major advantage of minimising allogenic blood use. Medical advancements and increase in access of care have lead to the steady increase in demand for allogenic blood. With number of patients on unavoidable chronic blood transfusion therapy (like those suffering from thalassemia) steadily increasing, rationalising and minimising the use of blood will ensure that adequate supply of blood continues to be available for all patients. Not to forget the huge cost saving which will result from the fewer infections and complications associated with minimising blood use.
The rule of thumb is - “Safest Blood Transfusion is No Blood Transfusion”.