Spine Surgeon NYU School of Medicine New Canaan, CT, US
Introduction: Tranexamic Acid(TXA) is used to reduce intraoperative blood loss, yet there is a paucity of literature examining appropriate dosing accounting for surgical invasiveness in spine surgery. This study aims to assess impact of surgical invasiveness on optimal dosing of TXA in order to reduce intraoperative blood loss.
Methods: Retrospective analysis of a single-center database. Patients with complete perioperative and TXA data were included. Based on prior literature1, loading dose was deemed low( < 10mg/kg), moderate(10–20mg/kg), or high(>20mg/kg). Maintenance dose was classified as low( < 1mg/kg/hour), moderate(1–2mg/kg/hour), or high(>2mg/kg/hour), however these categories were based on the maintenance dose distribution of our cohort. To assess impact of invasiveness, patients were separated into 3 groups by levels fused (LF): < 3 LF, 3–7LF, and >7LF. Within each group, Kruskal-Wallis and Quade rank analysis of covariance analyses were utilized to compare EBL for each level of loading and maintenance dose.
Results: 265 patients were included. There were no differences in EBL/hr by loading or maintenance dose for those with < 3LF. For those with 3–7LF, median EBL/hr was lower for low(64.3mL/hr) and moderate-loading-dose(77.8mL/hr) groups vs. high-loading-dose(121.6mL/hr), χ2(2) = 11.898,p=.003. Further, median EBL/hr was lower for patients who received a low maintenance dose(60.2mL/hr) vs. moderate(83.7mL/hr) and high(100.9mL/hr) dose groups(χ2(2) = 10.516,p=.005). For patients with >7LF, there were no differences in EBL/hr by loading dose, however the low maintenance dose group had higher median EBL/hr(444.5mL/hr) than those in the moderate(196.5mL/hr) and high(203.9mL/hr) maintenance groups(χ2(2) = 6.690, p=.035).
Conclusion : We found dosage of TXA associated with lowest EBL varied depending upon degree of surgical invasiveness. For patients undergoing >7 level fusion, a loading dose >20 mg/kg and maintenance >2mg/kg/hour were associated with significantly less blood loss. While further prospective analysis is warranted, these data suggest that optimal dosing of TXA may depend on degree of surgical invasiveness.
