The Results of Cardiac Surgery in Terms of Patient Blood Management in Türkiye Yüksek İhtisas Training and Research Hospital.

Dear Editor,

We read the interesting article by Sert et al. (1) published in Turkish Journal Anaesthesiology and Reanimation, wherein the primary aim was to compare the patient outcomes, requirement for transfusion, and cost of transfusion between two different periods with and without patient blood management (PBM) protocol. The authors found that the transfusion of unnecessary blood and blood products was reduced and the cost decreased with PBM protocol, although blood product usage did not affect 30-day mortality.

This article is valuable as it raises awareness about PBM, and will encourage centres to implement the PBM protocol. We want to thank the researchers and editors for bringing us this publication, and to highlight some points that may support the authors’ aim and provide more information for future investigations.

The authors stated that patients with “deep anaemia” in the preoperative evaluation were consulted at the haematology department. However, the authors did not mention any description or the threshold considered for deep anaemia. This clarification will contribute to the consensus among anaesthesiologists on which patients should consult the haematology department. In literature, the haemoglobin threshold for deep anaemia was defined as 7 g dL−1 (2, 3) or 8 g dL−1 (4, 5).

In PBM protocol, the threshold for intraoperative transfusion was stated as 7 g dL−1 in general and and 8–9 g dL−1 in patients with comorbidity, respectively. Moreover, in literature, some studies and reviews accept different thresholds for transfusion (6). However, in this article, the thresholds for the transfusions performed were not stated either before or after the PBM protocol.

In our opinion, specifying the number of patients, the threshold, and the number of units and type of blood product transfusion performed, in both groups, will enhance this article.

In the discussion section, the authors state that, after the PBM protocol, they discontinued the routine applications, patients were monitored more closely, and transfusion decision was taken only when necessary. We suggest the authors to clarify what they mean by “close monitoring” and “only when necessary”.

Expanding advanced monitoring methods have been a guide in making the right decision regarding the patients; however, conversely, it has become difficult to interpret the data correctly. Explaining the monitoring methods and sharing how they guided the transfusion decision will not only increase the value of this article but also help guide clinicians.

Finally, we are concerned that patients operated at different time intervals are subject to a methodological bias in terms of the equipment used, as patients operated in 2012 and 2017 were compared. As is known, the mini-circuits have been used during perfusion since 2014, which reduced the need for priming and prevented haemodilution. Although there are no definite indications of transfusions or the circuit types used in this article, the high blood transfusion rates detected in 2012 may be secondary to haemodilution.

In conclusion, we agree that PBM implementation is essential for both patient safety and cost reduction; further research is therefore needed in this area.