Clinical Trial Summary
Cardiac surgery is one of the clinical surgical specialties that carries a particularly high
risk for patients to suffer from severe bleeding perioperatively and consequent anemia, which
subsequently requires transfusion of allogeneic blood.
Although a surprisingly high number of patients in cardiac surgery do not require
perioperative transfusions, it is primarily those patients who do require transfusion who are
subsequently at risk for a worse outcome.
In recent years many studies have been published discussing measures that can assist
physicians in avoiding the triad of anemia, bleeding, and transfusion in cardiac surgery.
Within these publications, the implementation of Patient Blood Management (PBM) is advised.
PBM is a set of measures aimed at improving patient outcome by reducing perioperative
bleeding and thus preventing both anemia and bleeding.
The three pillars of this bundle are the preoperative preparation of anemic patients with
iron, erythropoietin, folic acid and vitamin B12, the prevention of intraoperative blood loss
and the reasonable indication for allogeneic transfusions.
Nevertheless, it must be mentioned that the implementation of at least part of these measures
is laborious, and full implementation of the recommended bundle is therefore rarely achieved.
As a consequence, the full potential of Patient Blood Management is not always realized.
Unfortunately this means that transfusion of allogeneic blood cannot be prevented in many
patients.
A small proportion of patients undergoing cardiac surgery requires a very large amount of
allogeneic blood perioperatively. These patients are typically those with a particularly poor
outcome. Massive transfusion of allogeneic blood in this situation is an indicator of
complications and a cause of increased mortality.
Although cardiac surgeons and anesthesiologists believe they can assess which patients are at
high risk for hemorrhage, recent publications indicate that there is an urgent need for
adequate predictive methods. A variety of studies exist that attempt to predict perioperative
transfusion requirements, but to date have been plagued by several limitations. Either the
previous publications do not focus on the prediction of massive transfusion of allogeneic
blood, i.e. administration of ten or more packed red blood cell units perioperatively, but on
much lower transfusion volumes, have only low predictive strength to predict massive
transfusion in daily clinical practice, or are hardly usable for true prediction because they
use factors (features) that are not strictly present only in the preoperative phase.
If an accurate prediction model based on a few features could be created and those patients
particularly at risk of massive transfusion of allogeneic blood could be identified, it would
subsequently be possible to develop an adapted clinical pathway that would allow patient care
to be improved and individualized interventions adapted to the situation to be implemented.
In the best case, an adapted care of patients would be possible, which is able to increase
the acceptance for the use of even complex measures of patient blood management. This is
especially true for measures such as preoperative preparation with iron and/or
erythropoietin, the use of a cell saver, and a particularly careful surgical approach.
Even if it is difficult to apply all measures of patient blood management in all patients, it
would be possible with an approach as described to identify those patients who would benefit
most from individualized approaches.
