Tranexamic acid dosing strategies and blood loss reduction in multilevel spine surgery: A systematic review and network meta-analysis Tranexamic acid for multilevel spine surgery

Background: For adults undergoing complex, multilevel spinal surgery, tranexamic acid (TXA) is an antifibrinolytic agent used to reduce blood loss. The optimal dosing of intravenous TXA remains unclear. This systematic review and meta-analysis compare various dosing regimens of intravenous TXA used in patients undergoing multilevel spine surgery ( >= 2 levels). Methods: PubMed, Cochrane, and EMBASE databases were searched for English language studies published January 2001 through May 2021 reporting use of TXA versus placebo for multilevel spine surgery. Primary outcomes of interest were intraoperative blood loss volume (BLV) and total BLV. A separate random effects model was fit for each outcome measure. Effect sizes were calculated as pooled mean differences (Diff) with corresponding 95% confidence intervals (CIs). Random effects network meta-analyses assessed whether the specific TXA dosing regimen influenced BLV. Results: Seven studies with 441 patients were included for meta-analysis. Four different TXA dosing regimens were found: 1) 10 mg/kg + 1 mg/kg/h, 2) 10 mg/kg + 2 mg/kg/h, 3) 15 mg/kg, 4) 15 mg/kg + 1 mg/kg/h. Compared to placebo, patients treated with TXA had reduced intraoperative BLV (Diff =-185.0 ml; 95% CI:-302.1,-67.9) and reduced total BLV (Diff =-439.0 ml; 95% CI:-838.5,-39.6). No significant differences in intraoperative BLV among any of the TXA treatment groups was found. Patients given a TXA dose of 15 mg/kg + 1 mg/kg/h had significantly reduced total BLV in comparison to both placebo (Diff =-823.1 ml; 95% CI:-1249.8,-396.4) and a dose of 15 mg/kg (Diff =-581.2; 95% CI:-1106.8,-55.7). Conclusions: This study found that intravenous TXA is associated with reduced intraoperative and total BLV, but it remains unclear whether there is an optimal TXA dose. Additional trials directly comparing different TXA regimens and administration routes are needed.