Is small volume, up to 2 red blood cell units transfusion required and redeemable in cardiac surgery?

Introduction: Low-volume (1-2 U) transfusion affects more than a quarter of cardiac surgical patients. This may increase the incidence of complications, mortality, and blood use, even in low-risk patients. Objective: By analyzing risk factors, we searched for measures to reduce the frequency of low-volume transfusions. Method: The risk factors for transfusion of up to 2 U red blood cells were examined in 1011 patients. We compared data from 276 (27.3%) patients who received low-volume transfusion (study group) with 448 (44.3%) patients who received no transfusion (control group). 287 patients (28,4%), who received more than 2 U red blood cells, were excluded. Multivariate logistic regression analysis of data was performed. Results: The factors affecting low-volume transfusion were female gender (OR= 2.048; p = 0.002), age (OR= 1.033; p = 0.002), body weight (OR= 0.954; p<0.001), preoperative hemoglobin value of <130 g/l (OR = 3.185; p<0.001), preoperative glomerular filtration rate <60 ml/min/1.73 m(2) (OR = 1.750; p = 0.026), off-pump coronary artery bypass surgery (OR = 0.371; p<0.001), combined procedures (OR = 2.432; p = 0.015), perioperative fluid balance (OR = 1.227; p = 0.005), intraoperative bleeding and preoperative clopidogrel treatment (OR = 1.002; p<0.001), postoperative bleeding >1200 ml/24 hours (OR= 2.438; p<0.005). Conclusion: Screening and treatment of preoperative anemia, decreasing operative hemodilution, increasing the number of minimally invasive and off-pump procedures as well as applying a surgical hemostasis protocol could be a solution to avoid low-volume transfusion in cardiac surgery.