title: Activity of factor VII in patients with isolated blunt traumatic brain injury: association with coagulopathy and progressive hemorrhagic injury.
abstract: BACKGROUND
  Given the importance of factor VII (FVII) in extrinsic pathway of coagulation cascade, we sought to elucidate the relationship between FVII and traumatic brain injury-induced coagulopathy and progressive hemorrhagic injury (PHI).
  
  
  METHODS
  Eighty-one patients with isolated traumatic brain injury, 16 years or older, were recruited between 2010 and 2012. Blood was collected on arrival in the emergency department and analyzed with activated partial thromboplastic time, international normalized ratio, platelet count, and activity of FVII. Coagulopathy was defined as thrombocytopenia (platelet count < 120,000/μL) or elevated international normalized ratio of greater than 1.2 or prolonged activated partial thromboplastin time greater than 40 seconds at admission. PHI was present when the follow-up computed tomographic scan reported any increase in size or number of the hemorrhagic lesions. Logistic regression examined the risks for coagulopathy and PHI.
  
  
  RESULTS
  Mean (SD) FVII activity in patients with coagulopathy was 85.69% (34.88%), which was significantly lower than patients without coagulopathy (99.57% [29.37%], p = 0.04). Isolated traumatic brain injury patients with FVII activity less than 77.5% have an odds ratio for coagulopathy of 5.52 (95% confidence interval, 1.82-16.68; p = 0.03) relative to patients with FVII activity of 77.5% or greater. Mean (SD) FVII activity in patients with PHI was 70.76% (18.21%), which was significantly lower than patients without PHI (105.76% [32.27%], p < 0.001). A stepwise logistic regression analysis identified FVII less than 77.5% (odds ratio, 4.53; 95% confidence interval, 1.62-12.67; p = 0.004) as a predisposing risk factors independently associated with the presence of PHI. The overall mortality rate in the study population was 7.4% (n = 6). The plasma FVII in death patients (91.44% [47.19%]) was slightly lower than that in survival patients (92.01% [32.04%]). However, there was no statistical difference between the two groups (p = 0.95).
  
  
  CONCLUSIONS
  A decrease of FVII activity significantly contributes to the coagulopathy and PHI in patients with isolated traumatic brain injury.
  
  
  METHODS
  Prognostic study, level III.
authors.affiliation: From the Department of Neurosurgery (X.W., Z.D., J.Y., Y.S., M.Y., L.Z., J.H.), Huashan Hospital, Fudan University; and SARI Center for Stem Cell and NanoMedicine (Z.T.), Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai; Department of Neurosurgery (B.P.), Henan Provincial People's Hospital, Xinxiang Medical University, Xinxiang City, Henan Province; and Department of Neurosurgery (X.L.), The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Wu
authors.forename: Zhuoying
authors.initials: Z
authors.lastname: Du
authors.forename: Jian
authors.initials: J
authors.lastname: Yu
authors.forename: Yirui
authors.initials: Y
authors.lastname: Sun
authors.forename: Bingbing
authors.initials: B
authors.lastname: Pei
authors.forename: Xin
authors.initials: X
authors.lastname: Lu
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Tang
authors.forename: Mao
authors.initials: M
authors.lastname: Yin
authors.forename: Liangfu
authors.initials: L
authors.lastname: Zhou
authors.forename: Jin
authors.initials: J
authors.lastname: Hu
mesh_terms: D001778:Blood Coagulation Disorders / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D005167:Factor VII / Q000502:physiology*; D005260:Female; D016489:Head Injuries, Closed / Q000097:blood / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D019934:International Normalized Ratio; D020198:Intracranial Hemorrhage, Traumatic / Q000097:blood / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D010976:Platelet Count; D011446:Prospective Studies; D013921:Thrombocytopenia / Q000209:etiology
chemical_list: D005167:Factor VII