title: The relative efficacy of antifibrinolytics in adolescent idiopathic scoliosis: a prospective randomized trial.
abstract: BACKGROUND
  Antifibrinolytics can reduce intraoperative blood loss. The primary aim of this study was to determine the efficacy of intraoperative tranexamic acid, epsilon-aminocaproic acid, and placebo at reducing perioperative blood loss and the transfusion rate in patients with adolescent idiopathic scoliosis undergoing posterior spinal arthrodesis.
  
  
  METHODS
  This is a prospective, randomized, double-blind comparison of tranexamic acid, epsilon-aminocaproic acid, and placebo used intraoperatively in patients with adolescent idiopathic scoliosis. One hundred and twenty-five patients with adolescent idiopathic scoliosis were randomly assigned to the tranexamic acid, epsilon-aminocaproic acid, or control groups. Parameters recorded included estimated blood loss, hematocrit, blood product usage, drain output, and total blood losses. The primary outcomes were intraoperative blood loss and postoperative drainage. Secondary outcomes were transfusion requirements and hematocrit changes both intraoperatively and postoperatively.
  
  
  RESULTS
  One hundred and twenty-five patients (ninety-seven female and twenty-eight male, with a mean age of fifteen years) were randomized to receive tranexamic acid (thirty-six patients), epsilon-aminocaproic acid (forty-two patients), or saline solution (forty-seven patients). The groups were similar at baseline, with one exception: the saline solution group had a higher estimated blood volume at baseline than the tranexamic acid group. Both tranexamic acid and epsilon-aminocaproic acid reduced the estimated blood loss per degree and estimated blood loss per pedicle screw. Epsilon-aminocaproic acid, but not tranexamic acid, reduced estimated blood loss and estimated blood loss per level. Tranexamic acid also reduced total blood losses compared with epsilon-aminocaproic acid or saline solution. In an analysis controlling for level, degree, and number of anchors, tranexamic acid reduced drain output and total blood losses. Tranexamic acid or epsilon-aminocaproic acid had a smaller decrease in hematocrit postoperatively. In an analysis controlling for the mean arterial pressure during surgical exposure, tranexamic acid reduced estimated blood loss and total blood losses. Overall, antifibrinolytics (tranexamic acid or epsilon-aminocaproic acid) reduced estimated blood loss, total blood losses, and the decline in hematocrit postoperatively compared with saline solution. There was no difference among the groups with respect to the transfusion rate, duration of surgery, levels fused, or pedicle screws placed.
  
  
  CONCLUSIONS
  Tranexamic acid and epsilon-aminocaproic acid reduced operative blood loss but not transfusion rate. Tranexamic acid is more effective at reducing postoperative drainage and total blood losses compared with epsilon-aminocaproic acid. Maintenance of the mean arterial pressure at &lt;75 mm Hg during surgical exposure appears to be critical for maximizing antifibrinolytic benefit.
  
  
  METHODS
  Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedics, Jefferson Medical College, Thomas Jefferson University, 834 Chestnut Street, Philadelphia, PA 19107.
authors.forename: Kushagra
authors.initials: K
authors.lastname: Verma
authors.affiliation: Spine Center, Department of Orthopaedics, Hospital for Joint Diseases, New York University, 306 East 15th Street, New York, NY 10003. E-mail address for A. Peters: aupeters@gmail.com.
authors.forename: Thomas
authors.initials: T
authors.lastname: Errico
authors.affiliation: Spine Center, Department of Orthopaedics, Hospital for Joint Diseases, New York University, 306 East 15th Street, New York, NY 10003. E-mail address for A. Peters: aupeters@gmail.com.
authors.forename: Chris
authors.initials: C
authors.lastname: Diefenbach
authors.affiliation: Spine Center, Department of Orthopaedics, Hospital for Joint Diseases, New York University, 306 East 15th Street, New York, NY 10003. E-mail address for A. Peters: aupeters@gmail.com.
authors.forename: Christian
authors.initials: C
authors.lastname: Hoelscher
authors.affiliation: Spine Center, Department of Orthopaedics, Hospital for Joint Diseases, New York University, 306 East 15th Street, New York, NY 10003. E-mail address for A. Peters: aupeters@gmail.com.
authors.forename: Austin
authors.initials: A
authors.lastname: Peters
authors.affiliation: Spine Center, Department of Orthopaedics, Hospital for Joint Diseases, New York University, 306 East 15th Street, New York, NY 10003. E-mail address for A. Peters: aupeters@gmail.com.
authors.forename: Joseph
authors.initials: J
authors.lastname: Dryer
authors.affiliation: Spine Center, Department of Orthopaedics, Hospital for Joint Diseases, New York University, 306 East 15th Street, New York, NY 10003. E-mail address for A. Peters: aupeters@gmail.com.
authors.forename: Tessa
authors.initials: T
authors.lastname: Huncke
authors.affiliation: Spine Center, Department of Orthopaedics, Hospital for Joint Diseases, New York University, 306 East 15th Street, New York, NY 10003. E-mail address for A. Peters: aupeters@gmail.com.
authors.forename: Kirstin
authors.initials: K
authors.lastname: Boenigk
authors.affiliation: Spine Center, Department of Orthopaedics, Hospital for Joint Diseases, New York University, 306 East 15th Street, New York, NY 10003. E-mail address for A. Peters: aupeters@gmail.com.
authors.forename: Baron S
authors.initials: BS
authors.lastname: Lonner
mesh_terms: D000293:Adolescent; D015119:Aminocaproic Acid / Q000008:administration & dosage*; D000933:Antifibrinolytic Agents / Q000008:administration & dosage*; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D001803:Blood Transfusion / Q000706:statistics & numerical data; D004311:Double-Blind Method; D005260:Female; D006400:Hematocrit / Q000379:methods; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D019990:Perioperative Care / Q000379:methods; D011446:Prospective Studies; D012600:Scoliosis / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods; D014148:Tranexamic Acid / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D000933:Antifibrinolytic Agents; D014148:Tranexamic Acid; D015119:Aminocaproic Acid