title: Vitamin K-dependent coagulation factor deficiency in trauma: a comparative analysis between international normalized ratio and thromboelastography.
abstract: BACKGROUND
  The use of international normalized ratio (INR) to diagnose vitamin K-dependent coagulation factor (VitK-CF) deficiency in trauma has limitations (inability to predict bleeding and long turnaround times). Thromboelastography (TEG) assesses the entire coagulation process. With TEG, reaction time (TEG-R) is used to assess global coagulation factor activity and takes less than 10 minutes. We assessed the ability of TEG-R to detect VitK-CF deficiency in trauma, compared to the INR.
  
  
  METHODS
  A total of 219 trauma patients with INR, TEG, and all VitK-CF measured at admission were included. Demographics and laboratory tests, drugs, blood transfusions, and severity scores were analyzed. Specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) of INR (≥1.3 and ≥1.5) and TEG-R (>8 min) to diagnose VitK-CF deficits (≤50%) were calculated. Secondary outcomes included time to INR and TEG results.
  
  
  RESULTS
  Overall, TEG-R performed worse than INR. TEG-R had a sensitivity of 33% (95% CI, 16%-55%), specificity of 95% (95% CI, 91%-98%), PPV of 47% (95% CI, 23%-72%), and NPV of 92% (95% CI, 87%-95%). An INR of 1.5 or greater had a sensitivity of 67% (95% CI, 45%-84%), specificity of 98% (95% CI, 96%-99.7%), PPV of 84% (95% CI, 60%-97%), and NPV of 96% (95% CI, 92%-98%). An INR of 1.3 or greater also had better sensitivity, PPV, and NPV. For patients on warfarin, the times to INR results and TEG completion were 58 (±23) and 92 (±40) minutes (p=0.07), respectively. TEG-R was abnormal in only one patient on warfarin.
  
  
  CONCLUSIONS
  Our study suggests that TEG-R is not superior at identifying VitK-CF deficiency compared to INR in trauma.
authors: Tory Regional Trauma Centre, Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
authors: Bartolomeu
authors: B
authors: Nascimento
authors: Mohammed
authors: M
authors: Al Mahoos
authors: Jeannie
authors: J
authors: Callum
authors: Antonio
authors: A
authors: Capone
authors: Jennifer
authors: J
authors: Pacher
authors: Homer
authors: H
authors: Tien
authors: Sandro
authors: S
authors: Rizoli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001777:Blood Coagulation / Q000502:physiology; D001779:Blood Coagulation Factors / Q000378:metabolism*; D001798:Blood Proteins / Q000172:deficiency*; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D013916:Thrombelastography; D014812:Vitamin K / Q000378:metabolism*; D014947:Wounds and Injuries / Q000378:metabolism*; D055815:Young Adult
chemical_list: D001779:Blood Coagulation Factors; D001798:Blood Proteins; D014812:Vitamin K