A Danish scientist, Niels Jerne, 1984 Nobel Prize winner in
medicine mentioned that “our own blood is like our digital
prints: there are not two types of blood that are identical”.
It is very interesting that he said so in response to why did
he refuse to receive blood transfusion (BT). This assumption
resumes quite nicely why most patients present at least
mild allergic reaction to BT. The red blood cell membrane
is extremely complex and has over 400 antigens already
described. Hence, the more people know about BT reactions,
disease transmission, and negative influence in clinical
outcomes, the more they reject red blood cell transfusión
in the context of surgery. Besides, it is getting more difficult
to find qualified blood donors since less people meet the
requirements for blood transfusion donors. This fact has
resulted in a shortage of blood supply in blood banks worldwide
which makes it necessary to seek out new treatment options. This compelling fact and evidence has impulse scientific
medicine to look for newer drug agents, techniques, medical
products and methods, as alternative procedures to BT.
Although, alternatives to BT and other treatment options exist
and there are medicine based evidence of their good results,
they are seldom utilized. However, it is not the aim of this
editorial to elaborate on the numerous alternatives that exist
to BT. There are several clinical and surgical strategies
that can be used to optimize hemoglobin and hematocrit
levels and coagulation status. Additionally, these measures
minimize blood loss, and improve anemia tolerance. In order
to improve clinical outcomes in open heart surgery, and to
diminish morbidity and mortality, as well as, reducing hospital
costs, these treatment strategies should be incorporated into
medical practice worldwide.
Despite of all this interesting facts, about 14 million units of
blood are donated annually in the USA, and about 4 million
people receive BT every year. There is a great variation
in the incidence of BT utilization in different hospitals. For
example, blood transfusion administration in surgical and
critical care settings varies among 30% to 100% of patients.
Open heart surgery is still associated with the risks of bleeding
and thrombotic events despite contemporary medical
maneuvers. More than five decades ago, it was arbitrarily
decided to transfuse patients with a hemoglobin level of
10 g/dl or less, and since then is relatively frequent to
observe a medical indication of BT in a similar situation. It is
not infrequent to observe a decrease in plasma hemoglobin
values under 10 g/dL in the immediate period after open
heart surgery. Although it seems that there is a clear
evidence of “winds of change”, it is still believed by many
physicians that patients would benefit from a BT that increases
the hemoglobin levels beyond 10 g/dL and the hematocrit
levels beyond 30%. The transfused whole blood is an excellent
plasma volume expander and stays in the intravascular
space much longer than any other volume expander. It is
undeniable that BT induces an increase in the plasma volume,
a hemodynamic improvement, and an increase in the cardiac
output and diuresis. However, there is strong medicine based
evidence that these mentioned clinical improvements are not
correlated with decreased morbidity and lesser mortality in
open heart surgery.
This is not an isolated finding. Similar results were demonstrated
in several observational studies showing clear association
between red blood cell transfusion and adverse outcomes in
open heart surgery. This negative influence is because
BT is in essence a transplant of allogeneic cells, consisting
of the infusion of multiple foreign antigens in great
quantities in the recipient´s circulation, resulting in several
inflammatory and immunological reactions. This adverse
association between BT and cardiac surgery has been shown
through decades in several studies and clinical observations
[22-32]. Indeed, Denton Cooley demonstrated similar findings
almost four decades ago. Therefore, these negative
outcomes with BT should be a call of attention to our routine
medical practice pointing directly to the risks of BT. Therefore,
unnecessary blood transfusions should be avoided to further
reduce the risk for ischemic events and other complications.
The evidence that BT carries significant risks points out to
avoid BT when possible. Moreover; it was also shown that a
single unit of red blood cell transfusion to a cardiac surgery
patient is associated to a decreased survival at 10 years after
the BT. The guidelines emphasize that the benefits of
transfusion have not been adequately demonstrated and
that existing evidence is an imperfect guide to transfusion
decisions, hence it was suggested a transfusion trigger of
hemoglobin less than 7 g/dL in postoperative cardiac surgery
patients with a class IIa level of indication
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