title: The Effect of Growing Rod Treatment on Hemoglobin and Hematocrit Levels in Early-onset Scoliosis.
abstract: BACKGROUND
  This study examines preoperative hemoglobin (Hgb) and hematocrit (Hct) levels in a group of early-onset scoliosis (EOS) patients and the effect of distraction-based growing rods (GRs) on these levels. Children with EOS are at risk for respiratory insufficiency and chronic hypoxemia. Increased Hgb and Hct levels have been identified as surrogate markers for chronic hypoxemia. A study of patients who underwent VEPTR surgery showed a significant decrease in Hgb levels following surgery.
  
  
  METHODS
  Data were retrospectively collected on 66 EOS patients without confounding respiratory issues or oxygen dependence who were treated with GRs at 5 institutions. Average age at initial surgery was 5.5 years. Patients were followed for a minimum of 2 years (average 3.7 y). Preoperative and postoperative Hgb and Hct levels were converted to Z-scores based on age-adjusted mean blood indices and were compared using a paired t test.
  
  
  RESULTS
  The prevalence of elevated Hgb and Hct levels (Z-score >2) preoperatively was 15% (10/66) and 19% (12/64), respectively. The average Hgb Z-score decreased from 0.20 to -0.31 (P=0.005) 6 to 24 months following surgery and the Hct Z-score decreased from 0.31 to -0.28 (P=0.002) 6 to 24 months following surgery.
  
  
  CONCLUSIONS
  Following distraction-based GR treatment of children with EOS there was a significant decrease in both their Hgb and Hct. This is a physiological marker of decreased hypoxemia and improved pulmonary function.
  
  
  METHODS
  Level III-therapeutic study.
authors.affiliation: *Children's Orthopaedic Center, Children's Hospital of Los Angeles †Department of Orthopaedics, University of California Los Angeles, Los Angeles ∥San Diego Center for Spinal Disorders, La Jolla, CA ‡Department of Orthopaedic Surgery, Texas Scottish Rite Hospital for Children, Dallas, TX §Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE.
authors.forename: Kody K
authors.initials: KK
authors.lastname: Barrett
authors.forename: Christopher
authors.initials: C
authors.lastname: Lee
authors.forename: Karen
authors.initials: K
authors.lastname: Myung
authors.forename: Charles
authors.initials: C
authors.lastname: Johnston
authors.forename: Suken A
authors.initials: SA
authors.lastname: Shah
authors.forename: Behrooz A
authors.initials: BA
authors.lastname: Akbarnia
authors.forename: David L
authors.initials: DL
authors.lastname: Skaggs
mesh_terms: D017668:Age of Onset; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D002648:Child; D002675:Child, Preschool; D005260:Female; D006400:Hematocrit / Q000379:methods*; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000453:epidemiology / Q000209:etiology / Q000628:therapy; D008297:Male; D008349:Manipulation, Orthopedic / Q000009:adverse effects / Q000379:methods; D010043:Outcome and Process Assessment, Health Care; D010102:Oxygen Inhalation Therapy / Q000379:methods; D015995:Prevalence; D012131:Respiratory Insufficiency / Q000097:blood / Q000209:etiology; D012189:Retrospective Studies; D012600:Scoliosis / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D014481:United States
chemical_list: D015415:Biomarkers; D006454:Hemoglobins