IJCS | Volume 32, Nº6, November / December 2019

DOI: https://doi.org/10.36660/ijcs.20190187 573 EDITORIAL International Journal of Cardiovascular Sciences. 2019;32(6):573-575 Mailing Address: Fernanda Azevedo-Silva Hospital Universitario Antonio Pedro – Hemocentro – Rua Marques do Paraná,303. Postal Code: 24033-900, Niterói, RJ - Brazil. E-mail: azevedosilva.fernanda@gmail.com Blood Transfusion in Cardiac Surgery: Less is More? Fernanda Azevedo-Silv a Hospital Universitário Antonio Pedro - Hemocentro, Niterói, RJ - Brazil Editorial related to the article: Adverse Events and Risk Factors of Blood Transfusion in Cardiovascular Surgery: A Prospective Cohort Study Blood Transfusion/methods; Thoracic Surgery/ complications; Risk Factors; Mortality; Perioperative Care. Keywords Blood transfusion is one of the most common medical procedures, 1 and a major part of these are performed during cardiac surgeries. The incidence of perioperative transfusion in cardiac surgeries varies from 40 to 90%, 2 according to the complexity of the procedure and the protocols adopted in each institution. ThestudybyTagliarietal., 3 publishedintheInternational Journal of Cardiovascular Sciences, analyzed the use of blood transfusion and postoperative outcomes within 30 days in patients undergoing cardiac surgery in a Brazilian tertiary hospital between 2015 and 2017. In this prospective cohort, subjects were divided into those who received transfusion and those who did not. Patients most likely to receive blood transfusion were patients with previous cardiac surgery, longer time of cardiopulmonary bypass, chronic kidney disease recent use of oral anticoagulants and antiplatelet agents, left ventricular ejection fraction less than or equal to 30%, lower preoperative hemoglobin levels, and changes in coagulation, urea and creatinine tests. Patients in the transfused group had more severe disease than those in the non-transfused group, withmore patients reoperated and taking medications that could interfere with blood coagulation, both factors associated with increased bleeding and need for transfusion. However, blood transfusion was an independent risk factor formortality inmultivariate analysiswhen adjusted for major confounders. Transfused patients had higher mortality, higher rates of bronchopneumonia and acute kidney injury, longer hospital stay and mechanical ventilation. The authors concluded that blood transfusion should be reconsidered in cardiac surgery, because even transfusion of a blood component unit was associated with a worse postoperative outcome. Since transfusion is one of the few modifiable factors that may worsen the prognosis of surgery, strategies to prevent transfusion should be encouraged. The main criticism about this study is that, as an observational one, had no possibility of randomization, with high chance of bias, which made it difficult to establish a causal relationship. Finding the right balance between the risks and benefits of transfusion is a challenge that has been the subject of recent studies. Common complications of blood transfusion are described in Table 1; 4 these range from mild to severe and may even lead to death. The most common reactions, such as nonhemolytic fever and allergic fever, are self-limiting and mild in intensity. Acute hemolytic reaction is rare, but potentially fatal, and is associatedwith patient'smisidentification. Transfusion- related acute lung injury (TRALI) is currently the leading cause of blood transfusion-related mortality. Together with transfusion-associated circulatory overload (TACO), TRALI causes respiratory dysfunction that adds morbidity to the patients’ clinical condition, especially in the context of cardiac surgery. Immunomodulation and transmission of infectious agents are other potential complications of blood transfusion. The combination of overuse of blood, 1 transfusion- related risks and limited availability of blood components stimulated the development of restrictive transfusion strategies and led to the development of patient blood management (PBM). PBM consists of a set of actions aimed at reducing the need for transfusion by encouraging detection and treatment of anemia before surgery, use of surgical techniques and several procedures focused on preservation of patient's own blood, use of medications that reduce bleeding, and discontinuation of others that may interfere with blood coagulation. PBM strategies are also aimed at reducing blood collection for