title: Moderate elevations in international normalized ratio should not lead to delays in neurosurgical intervention in patients with traumatic brain injury.
abstract: BACKGROUND
  The management of severe traumatic brain injury (TBI) frequently involves invasive intracranial monitoring or cranial surgery. In our institution, intracranial procedures are often deferred until an international normalized ratio (INR) of less than 1.4 is achieved. There is no evidence that a moderately elevated INR is associated with increased risk of bleeding in patients undergoing neurosurgical intervention (NI). Thrombelastography (TEG) provides a functional assessment of clotting and has been shown to better predict clinically relevant coagulopathy compared with INR. We hypothesized that in patients with TBI, an elevated INR would result in increased time to NI and would not be associated with coagulation abnormalities based on TEG.
  
  
  METHODS
  A secondary analysis of prospectively collected data was performed in trauma patients with intracranial hemorrhage that underwent NI (defined as cranial surgery or intracranial pressure monitoring) within 24 hours of arrival. Time from admission to NI was recorded. TEG and routine coagulation assays were obtained at admission. Patients were considered hypocoagulable based on INR if their admission INR was greater than 1.4 (high INR). Manufacturer-specified values were used to determine hypocoagulability for each TEG variable.
  
  
  RESULTS
  Sixty-one patients (median head Abbreviated Injury Scale [AIS] score, 5) met entry criteria, of whom 16% had high INR. Demographic, physiologic, and injury scoring data were similar between groups. The median time to NI was longer in patients with high INR (358 minutes vs. 184 minutes, p = 0.027). High-INR patients were transfused more plasma than patients with an INR of 1.4 or less (2 U vs. 0 U, p = 0.01). There was no association between an elevated INR and hypocoagulability based on TEG.
  
  
  CONCLUSIONS
  TBI patients with an admission INR of greater than 1.4 had a longer time to NI. The use of plasma transfusion to decrease the INR may have contributed to this delay. A moderately elevated INR was not associated with coagulation abnormalities based on TEG. Routine plasma transfusion to correct a moderately elevated INR before NI should be reexamined.
  
  
  METHODS
  Diagnostic study, level III.
authors.affiliation: From the Departments of Surgery (S.E.R., T.C.L., K.A.F., S.J.U., M.A.S.), and Neurological Surgery (A.J.R.), Oregon Health and Science University; and Trauma Services (R.R.B.), Legacy Emanuel Hospital and Health Center, Portland, Oregon.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Rowell
authors.forename: Ronald R
authors.initials: RR
authors.lastname: Barbosa
authors.forename: Tori C
authors.initials: TC
authors.lastname: Lennox
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Fair
authors.forename: Abigail J
authors.initials: AJ
authors.lastname: Rao
authors.forename: Samantha J
authors.initials: SJ
authors.lastname: Underwood
authors.forename: Martin A
authors.initials: MA
authors.lastname: Schreiber
mesh_terms: D015998:Abbreviated Injury Scale; D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000097:blood* / Q000601:surgery; D002543:Cerebral Hemorrhage / Q000097:blood / Q000601:surgery; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D007427:Intracranial Pressure; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013916:Thrombelastography; D013997:Time Factors; D055815:Young Adult