BackgroundThis study aimed to evaluate the efficacy and safety of posttraumatic antifibrinolytic therapy with repeated doses of intravenous tranexamic acid (IV-TXA) in reducing perioperative hidden blood loss (HBL) in elderly intertrochanteric femur fracture (IFF) patients. Method112 elderly IFF patients who were admitted to our department from March 2020 to May 2021 were randomized to receive 100 ml of normal saline (Control group) or 1.5 g of TXA (TXA group) intravenously q12 hours from postadmission day 1 (PAD1) to PAD3. Hemoglobin (Hb), hematocrit (Hct), fibrinogen degradation product (FDP), D-dimer (D-D), and coagulation parameters were recorded from PAD1 to postoperative day 3 (POD3). HBL was calculated using the gross formula and recorded as the primary outcome. ResultThe patients in TXA group had lower preoperative hidden blood loss(HBL), decline of hemoglobin(ΔHb), FDP (on PAD3), and D-D (on PAD3) compared with control group, while no difference was found in postoperative HBL, postoperative ΔHb and allogeneic blood transfusion (ABT) rate. In subgroup analyses, it was observed that patients who received the intervention within 24 hours of injury and between 24 and 72 hours of injury exhibited significantly lower preoperative HBL and ΔHb in the TXA group compared with the control group. Furthermore, the reduction in HBL and ΔHb was more pronounced in the former group. While for patients who received the intervention beyond 72 hours after injury, no significant differences were observed in preoperative HBL and ΔHb between the two groups. Similarly, no significant differences were noted in postoperative HBL and ΔHb between the TXA and control groups across all subgroups. Additionally, no significant differences were identified in the incidence of venous thromboembolism (VTE) and mortality within one year between the two groups. ConclusionPost-traumatic antifibrinolytic therapy with repeated doses of intravenous TXA is effective and safe in reducing perioperative HBL for elderly IFF patients, especially for patients injured within 24 hours.