Relationship between the severity of preoperative anemia and postoperative deep vein thrombosis in patients with bone trauma: a cohort study

Abstract

Objective To analyze the relationship between preoperative anemia and postoperative deep vein thrombosis (DVT) in patients with lower limb bone trauma who have a high rate of preoperative anemia. Method In this retrospective cohort study, 957 patients at our center were included. Patients were categorized based on their last preoperative hematocrit (HCT) results. The univariate analysis included general preoperative conditions, complications, surgical and fracture-related factors, preoperative laboratory indicators, anticoagulation, and anemia in patients with DVT (284 cases) and those without DVT (673 cases) after surgery. Results Among the 284 cases with postoperative thrombosis, 61(21.5%) had no anemia before surgery, while 223(78.5%) had anemia before surgery. Among those with anemia, 65(22.9%) had mild anemia, and 158 had moderate to severe anemia. Age over 65 years old, total length of stay (LOS) exceeding 14 days, preoperative anticoagulation, delay of more than 24 h in starting anticoagulation after surgery, 30%≤HCT < 33% and blood transfusion, and HCT < 27% and blood transfusion were identified as independent risk factors for postoperative DVT formation. The ROC curves showed that a preoperative HCT of 35.15% (AUC = 0.670, sensitivity = 64.6%, specificity = 61.2%) in males and 33.45% (AUC = 0.637, sensitivity = 63.7%, specificity = 60.2%) in females were the cut-off values for predicting postoperative DVT occurrence. Conclusions The risk of postoperative DVT increases with the severity of preoperative anemia in patients with bone trauma, and perioperative blood transfusion further increases the risk of DVT. Trial registration: ChiCTR2100049356.