title: Preliminary investigation of high-dose tranexamic acid for controlling intraoperative blood loss in patients undergoing spine correction surgery.
abstract: BACKGROUND
  With a significant increase in the number and complexity of spinal deformity corrective surgeries, blood loss, often requiring massive intraoperative transfusions, becomes a major limiting factor during surgery. This scenario is particularly during posterior vertebral column resection (PVCR), where extensive intraoperative blood loss may pose a major risk to the patient, preventing smooth execution of the procedure. Tranexamic Acid (TXA) has been used in cardiac and orthopedic surgeries, including major spinal surgeries, to reduce blood loss and transfusion requirements for decades.
  
  
  OBJECTIVE
  To assess the efficacy and safety of high doses of TXA in posterior spinal deformity corrective surgery, including PVCR procedures.
  
  
  METHODS
  A retrospective study from a single institution.
  
  
  METHODS
  Fifty-nine patients (age range 7 to 46 years old) with spinal deformities undergoing spinal corrective surgeries were included. The patients were divided into two groups: the TXA group (total of 26 patients, including 8 PVCR patients) and the control group (total of 33 patients, including 9 PVCR patients).
  
  
  METHODS
  The analyzed outcome measures included estimated intraoperative blood loss, real blood loss (RBL; blood loss/blood volume×100%), blood transfusion requirements, coagulation parameters, complete blood count, liver function, and renal function. Lower limb vein thrombus, symptomatic pulmonary embolism, symptomatic myocardial infarction, seizures, and acute renal failure were also recorded.
  
  
  METHODS
  Before skin incision, the patients in the TXA group received an intravenous loading dose of 100 mg/Kg over a 20-minute period, followed by a maintenance infusion of 10 mg/Kg/h until skin closure was completed. The patients in the control group received saline infusion of a similar volume. Statistics included estimated intraoperative blood loss, RBL, blood transfusion requirements, coagulation parameters, complete blood count, liver function, and renal function. All patients in this study were also carefully monitored for consciousness level, breathing status, chest tightness or pain, and urine output after surgery. These were done to detect the presence or absence of pulmonary embolism, myocardial infarction, seizures, and acute renal failure. Patients treated with TXA were examined via vascular ultrasound before and after surgery.
  
  
  RESULTS
  There were no significant differences in the demographic or surgical traits between the two groups. The blood loss of the patients in the TXA group was 2,441±1,666 mL, whereas that of the control group patients was 4,789±4,719 mL. The difference was statistically significant (p<.05). The average RBL of the patients in the TXA group was 80.6%±49.6% versus 160.8%±163.1% in the control group (p<.05). The blood transfusion requirements for the patients in the TXA group were significantly less than that in the control group (p<.05). Blood loss, RBL, and blood transfusion requirements were all significantly lower in the TXA group, compared with the control group among both PVCR patients and non-PVCR patients. In the TXA group, there was an average of 57.4% reduced blood loss in patients who received PVCR and 39.8% in patients not receiving PVCR. There were no differences in liver and renal functions between the TXA and control groups. There was no lower limb vein thrombus, symptomatic myocardial infarction, symptomatic pulmonary embolism, seizures, or acute renal failure reported in the TXA group.
  
  
  CONCLUSIONS
  In our study, high doses of TXA have been shown to effectively control blood loss and reduce the transfusion requirement. This effect was more apparent in patients receiving PVCR. No adverse drug reaction was recorded in the study. In the future, prospective randomized controlled trials to validate our results will be necessary. Future studies conducted on older patient cohort may also be necessary to confirm the safety of extending the use of TXA to the older patients.
authors.affiliation: Department of Orthopaedic Surgery, 2nd Affiliated Hospital of Kunming Medical University, Dianmian Road 374, Kunming, Yunnan Province, P.R. China, 650101. Electronic address: xiejingming@vip.163.com.
authors.forename: Jingming
authors.initials: J
authors.lastname: Xie
authors.affiliation: Department of Orthopaedic Surgery, Washington University Medical Center, Suite 11300, Campus Box 8233, St. Louis, MO 63110, USA.
authors.forename: Lawrence G
authors.initials: LG
authors.lastname: Lenke
authors.affiliation: Department of Orthopaedic Surgery, 2nd Affiliated Hospital of Kunming Medical University, Dianmian Road 374, Kunming, Yunnan Province, P.R. China, 650101.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, 2nd Affiliated Hospital of Kunming Medical University, Dianmian Road 374, Kunming, Yunnan Province, P.R. China, 650101.
authors.forename: Yongyu
authors.initials: Y
authors.lastname: Si
authors.affiliation: Department of Orthopaedic Surgery, 2nd Affiliated Hospital of Kunming Medical University, Dianmian Road 374, Kunming, Yunnan Province, P.R. China, 650101.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Orthopaedic Surgery, 2nd Affiliated Hospital of Kunming Medical University, Dianmian Road 374, Kunming, Yunnan Province, P.R. China, 650101.
authors.forename: Yingsong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Orthopaedic Surgery, 2nd Affiliated Hospital of Kunming Medical University, Dianmian Road 374, Kunming, Yunnan Province, P.R. China, 650101.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedic Surgery, 2nd Affiliated Hospital of Kunming Medical University, Dianmian Road 374, Kunming, Yunnan Province, P.R. China, 650101.
authors.forename: Jie
authors.initials: J
authors.lastname: Xiao
mesh_terms: D000293:Adolescent; D000328:Adult; D000933:Antifibrinolytic Agents / Q000627:therapeutic use*; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013131:Spine / Q000601:surgery*; D014148:Tranexamic Acid / Q000627:therapeutic use*
chemical_list: D000933:Antifibrinolytic Agents; D014148:Tranexamic Acid
keywords: Blood loss; Blood transfusion; Posterior spinal deformity corrective surgery; Posterior vertebral column resection; Spinal deformities; Tranexamic acid