Introduction:Complex spine surgeries are associated with notable blood loss requiring numerous strategies to preserve blood volume. Tranexamic acid (TXA) is efficacious in reducing blood loss when used topically during surgery, intravenously with or without postoperative maintenance treatment. We aimed to evaluate the effect of preoperative weight-independent intravenous administration of 1 g intravenous TXA on perioperative blood loss in lumbar microdiskectomy, single-level lumbar spinal fusion, and multilevel lumbar decompression (two or more levels).Methods:This is a retrospective cohort study comparing patients who underwent microdiskectomy, single-level lumbar fusion, and multilevel laminectomies with and without preoperative IV TXA administration between 2016 and 2020.Results:Two hundred ten patients underwent spine surgery without preoperative IV TXA administration between 2016 and 2018 compared with 109 patients who received preoperative 1 g of IV TXA between 2018 and 2020. Preoperative IV TXA treatment did not change blood loss after microdiskectomy, 77.2 ± 53.9 mL and 77.2 ± 95.2 mL, respectively (P = 0.792). Preoperative IV TXA treatment reduced blood loss after multilevel lumbar laminectomy and lumbar posterior spinal fusion with a transforaminal intervertebral fusion (PSF and TLIF) (P = 0.004 and P = 0.0001, respectively). The same effect was found for intraoperative blood loss and postoperative drainage, with preoperative TXA administration reducing intraoperative blood loss and postoperative drainage for the multilevel lumbar laminectomy and lumbar PSF and TLIF cohorts. No IV TXA treatment adverse events were registered in all cohorts.Conclusion:A routine administration of preoperative weight-independent 1 g intravenous TXA protocol is efficacious and safe in reducing perioperative blood loss for lumbar multilevel laminectomies and PSF and TLIFs.