Bleeding Kinetics after Total Hip or Knee Replacement: A Prospective Observational Study

Abstract

Background and objectives: The objective was to assess the kinetics of postoperative bleeding after total hip or knee replacement, with or without administration of tranexamic acid, in order to anticipate red blood cell transfusion thresholds in the recovery room. Materials and methods: This was a prospective, observational, single-center study. All patients undergoing primary or revision total hip or knee replacement were enrolled for two months. Patients were managed using a multimodal strategy designed to reduce the need for red blood cell transfusion. Postoperative bleeding kinetics was assessed according to the drop of hemoglobin levels between the arrival in the recovery room and day one after surgery. Results: A total of 106 patients were included. The mean transfusion rate was 18%. Nadir hemoglobin levels were observed on day + 2, and about 60% of bleeding occurred during the postoperative period, with a drop of 1.2 ± 0.2 g/dL between the recovery room and day one for patients receiving tranexamic acid, and 1.9 ± 0.2 g/dL for those not receiving tranexamic acid (p=0.018). Discussion: In our center, the hemoglobin transfusion threshold in recovery room might be raised by 1 or 2 g/ dL depending on whether tranexamic acid is used.