The characteristics of blood transfusion and analysis of preoperative factors associated with intraoperative blood transfusion in congenital heart surgery: a case–control study

Purpose Blood transfusion is a common and life-saving procedure in congenital heart surgery (CHS), and it is critical for patients to identify risk factors prior to surgery. Our objective is to conduct an analysis of the preoperative factors that influence blood use during CHS and to offer guidance on preoperative blood preparation. Methods A total of 1550 cases were retrospectively analyzed in our institution between May 2019 and June 2020. We determined whether to employ red blood cells (RBCs), platelets, and plasma as dependent variables; we treated the data from characteristics and laboratory tests as binary data, except for the Risk Adjustment for Congenital Heart Surgery (RACHS) methods as multinomial data, and finally taken into binary logistic regression analysis. Results The total amounts of transfused RBCs, platelets, and plasma were 850.5 U (N = 713, 46%), 159 U (N = 21, 1.4%), and 1374.2 U (N = 953, 61.5%), respectively. Multivariate analysis found age (OR 0.142, 95% CI 0.099–0.203, P < 0.001), weight (0.170, 0.111–0.262, P < 0.001) RACHS method (RACHS2 vs. RACHS1, 3.444, 2.521–4.704, P < 0.001; RACHS3 vs. RACHS1, 9.333, 4.731–18.412, P < 0.001; RACHS4 vs. RACHS1, 31.327, 2.916–336.546, P = 0.004), and hemoglobin (0.524, 0.315–0.871, P = 0.013) to be independent risk predictors of RBC transfused volume; age (9.911, 1.008–97.417, P = 0.049), weight (0.029, 0.003–0.300, P = 0.029), RACHS method (RACHS3 vs. RACHS1, 13.001, 2.482–68.112, P = 0.002; RACHS4 vs. RACHS1, 59.748, 6.351–562.115, P < 0.001) to be platelets; and age (0.488, 0.352–0.676, P < 0.001), weight (0.252, 0.164–0.386, P < 0.001), RACHS method (RACHS2 vs. RACHS1, 2.931, 2.283–3.764, P < 0.001; RACHS3 vs. RACHS1, 10.754, 4.751–24.342, P < 0.001), APTT (1.628, 1.058–2.503, P = 0.027), and PT (2.174, 1.065–4.435, P = 0.033) to be plasma. Conclusion Although patients' age, weight, routine blood test, coagulation function, and protein levels should all be considered for preparing blood before CHS, the RACHS method is the most important factor influencing intraoperative blood transfused volume and should be considered first in clinical blood preparation.