title: When children become adults and adults become most hypercoagulable after trauma: An assessment of admission hypercoagulability by rapid thrombelastography and venous thromboembolic risk.
abstract: BACKGROUND
  Thrombelastography (TEG) maximal amplitude (mA) has also been shown to reflect hypercoagulability and increased venous thromboembolism (VTE) risk in adult trauma patients. Based on these previous works, we sought to identify when children become adults with respect to TEG mA values and whether this correlated with VTE risk.
  
  
  METHODS
  We evaluated all trauma patients admitted from January 2010 to December 2013 who were highest-level activations. Age was evaluated as a continuous variable, followed by a categorical evaluation. TEG mA values were evaluated as continuous and dichotomous (hypercoagulable, mA ≥ 65 mm). Logistic regression was then constructed controlling for age categories, sex, and injury severity to assess the association with TEG mA values and VTE risk.
  
  
  RESULTS
  A total of 7,194 Level 1 trauma patients were admitted during this time frame (819 were <18 years of age). The likelihood of mA equal to or greater than 65 mm remained at 35% to 37% through age 30 years with significant increases observed at ages 31 years to 35 years (45%) and 46 years to 50 years (49%), both p < 0.01. When controlling for injury severity, race, and sex, logistic regression demonstrated that every 5-year increase in age (after age 30 years) was associated with a 16% increased likelihood of hypercoagulability at admission. Beginning with age 1 year, VTE risk remained at 1.5% or less until age 13 years where it increased to 2.3%, increasing again at age 15 years to 5.1%. Two additional significant increases were identified between ages 31 years and 35 years (5.5%) as well as 46 years and 50 years (7.6%), both p < 0.001. Logistic regression demonstrated a 3.4-fold increased risk for VTE among those aged 31 years to 50 years compared with those who are younger than 30 years. The same model noted a 2.3-fold increased risk compared with those who are older than 50 years.
  
  
  CONCLUSIONS
  Beginning at age 13 years, children transition toward adult hypercoagulability, as evidenced by elevated TEG mA values and VTE risk. However, the greatest VTE risk (and highest likelihood of hypercoagulable mA) is among those adults 31 years to 50 years of age.
  
  
  METHODS
  Prognostic and epidemiologic study, level III.
authors.affiliation: From the Departments of Surgery (I.N.L., E.R., J.H., B.A.C.) and Pediatric Surgery (M.T.H.), The Center for Translational Injury Research (J.H., B.A.C.), and The Center for Surgical Trials and Evidence-based Practice (M.T.H., B.A.C.), The University of Texas Medical School at Houston, Houston, Texas.
authors.forename: Ioannis N
authors.initials: IN
authors.lastname: Liras
authors.forename: Elaheh
authors.initials: E
authors.lastname: Rahbar
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Harting
authors.forename: John B
authors.initials: JB
authors.lastname: Holcomb
authors.forename: Bryan A
authors.initials: BA
authors.lastname: Cotton
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010343:Patient Admission / Q000706:statistics & numerical data*; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D017678:Sex Distribution; D013916:Thrombelastography / Q000379:methods*; D019851:Thrombophilia / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D014481:United States / Q000453:epidemiology; D054556:Venous Thromboembolism / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D014947:Wounds and Injuries / Q000150:complications* / Q000453:epidemiology; D055815:Young Adult