Risk Factors for the Postoperative Transfusion of Allogeneic Blood in Orthopedics Patients With Intraoperative Blood Salvage: A Retrospective Cohort Study

The purpose of this study is to explore the risk factors affecting the postoperative transfusion of allogeneic blood in patients undergoing orthopedics surgery with intraoperative blood salvage (IBS). A retrospective study of 279 patients undergoing orthopedic surgeries with IBS from May 2013 to May 2015 was enrolled. The binary logistic regression was used to find out the risk factors associated with postoperative transfusion of allogeneic blood in orthopedics patients with IBS, and then receiver operating characteristic (ROC) curve was drawn to determine the optimal threshold of the regression model. Single factor analysis showed that age, American Society of Anesthesiologists (ASA) grade, preoperative hemoglobin, operation time, received autologous blood, the laying time of autologous blood, bleeding volume, and postoperative drainage volume had significant effects on postoperative allogeneic blood transfusion. In binary logistic regression analysis, the independent factors predicting orthopedic patients with IBS need to transfuse allogeneic blood after surgeries were age (odds ratio [OR] = 0.415, P = 0.006), ASA grade (OR = 2.393, P = 0.035), preoperative hemoglobin (OR = 0.532, P = 0.022), and postoperative drainage volume (OR = 4.279, P = 0.000). The area under ROC curve was 0.79 and the predicted accuracy rate of the model was 81.58%. After operation, the orthopedic patients with IBS still have a high allogeneic blood transfusion rate, and IBS is not a perfect blood protection method. The logistic regression model of our study provides a reliable prediction for postoperative transfusion of allogeneic blood in orthopedic patients with IBS, which have a certain reference value.