title: Pre-Operative Autologous Blood Donation Does Not Affect Pre-Incision Hematocrit in Adolescent Idiopathic Scoliosis Patients. A Retrospective Cohort of a Prospective Randomized Trial.
abstract: BACKGROUND
  Pre-donation of autologous blood prior to spine fusion for adolescent idiopathic scoliosis (AIS) has been used in deformity surgery. The effect of pre-donation on pre-operative hematocrit (Hct) remains debated. Multiple factors may influence pre-operative Hct including intravascular volume status, patient factors, and timing of pre-operative blood donation. The purpose of this study was to determine if pre-donation significantly lowers pre-incision Hct in AIS patients.
  
  
  METHODS
  A retrospective cohort study of a Level-1 prospective randomized trial was conducted. 125 patients from the homogeneous population were included. AIS patients undergoing a posterior only spinal fusion for AIS were separated into two groups based on their pre-operative blood donation history. Demographic variables, pre-incision Hct, and transfusion rates were compared between the two groups using the Student's T-test.
  
  
  RESULTS
  Pre-donation and non pre-donation groups had 28 and 97 patients, respectively. Pre-donation group was 75% female (21F, 7M) and non pre-donation group was 78% female (76F, 21M). There was no difference between pre-donation and non pre-donation groups in mean age (15.6 ± 2.2 vs 14.8 ± 2.2, p = 0.081), BMI (23.1 ± 4.2 vs 21.7 ± 5.3, p = 0.219), and pre-incision Hct (32.8 ± 3.4 vs 33.8 ± 3.1, p = 0.628). The overall transfusion rates were equivalent (32.1± 48.0% vs 25.8 ± 44.0%, p = 0.509), however, the rate of allogenic transfusion for the pre-donation group was significantly lower (3.6 ± 18.9% vs 25.8 ± 44.0%, p = 0.011).
  
  
  CONCLUSIONS
  This study supports the use of pre-donation for AIS, without a significant drop in pre-incision Hct. Patients that donate are also much less likely to be exposed to allogenic blood. There may be a surgeon bias to recommend pre-donation in patients with a larger BMI and older age. Future studies are needed from a larger population of patients including those with non-AIS pathology.
  
  
  METHODS
  Level III.
authors.affiliation: Division of Spinal Surgery, Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY; Department of Orthopaedic Surgery, Drexel College of Medicine, Hahnemann University Hospital, Philadelphia, PA.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Boniello
authors.affiliation: Division of Spinal Surgery, Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY; Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA.
authors.forename: Kushagra
authors.initials: K
authors.lastname: Verma
authors.affiliation: Division of Spinal Surgery, Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY.
authors.forename: Austin
authors.initials: A
authors.lastname: Peters
authors.affiliation: Department of Orthopaedic Surgery, Mount Sinai Beth Israel, New York, New York.
authors.forename: Baron S
authors.initials: BS
authors.lastname: Lonner
authors.affiliation: Division of Spinal Surgery, Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY.
authors.forename: Thomas
authors.initials: T
authors.lastname: Errico
keywords: adolescent idiopathic scoliosis; autologous blood; blood transfusion; hematocrit; spine surgery