Approach to red blood cell transfusions in post-operative congenital heart disease surgery patients: when to stop?

Background: The best transfusion approach for CHD surgery is controversial. Studies suggest two strategies: liberal (haemoglobin ≤ 9.5 g/dL) and restrictive (waiting for transfusion until haemoglobin ≤ 7.0 g/dL if the patient is stable). Here we compare liberal and restrictive transfusion in post-operative CHD patients in a cardiac intensive care unit.

Methods: Retrospective analysis was conducted on CHD patients who received liberal transfusion (2019-2021, n=53) and restrictive transfusion (2021-2022, n=43).

Results: The two groups were similar in terms of age, gender, Paediatric Risk of Mortality-3 score, Paediatric Logistic Organ Dysfunction-2 score, Risk Adjustment for Congenital Heart Surgery-1 score, cardiopulmonary bypass time, vasoactive inotropic score, total fluid balance, mechanical ventilation duration, length of cardiac intensive care unit stay, and mortality. The liberal transfusion group had a higher pre-operative haemoglobin level than the restrictive group (p < 0.05), with no differences in pre-operative anaemia. Regarding the minimum and maximum post-operative haemoglobin levels during a cardiac intensive care unit stay, the liberal group had higher haemoglobin levels in both cases (p<0.01 and p=0.019, respectively). The number of red blood cell transfusions received by the liberal group was higher than that of the restrictive group (p < 0.001). There were no differences between the two groups regarding lactate levels at the time of and after red blood cell transfusion. The incidence of bleeding, re-operation, acute kidney injury, dialysis, sepsis, and systemic inflammatory response syndrome was similar.

Conclusions: Restrictive transfusion may be preferable over liberal transfusion. Achieving similar outcomes with restrictive transfusions may provide promising evidence for future studies.