title: The international normalized ratio overestimates coagulopathy in patients after major hepatectomy.
abstract: BACKGROUND
  The International Normalized Ratio (INR) is commonly used to guide therapy after hepatectomy. We hypothesized that the use of thrombelastography (TEG) would demonstrate a decreased incidence of hypocoagulability in this patient population.
  
  
  METHODS
  Seventy-eight patients were prospectively enrolled before undergoing hepatectomy. INR, TEG, and coagulation factors were drawn before incision, postoperatively, and on postoperative days 1, 3, and 5.
  
  
  RESULTS
  Patients demonstrated an elevated INR at all postoperative time points. However, TEG demonstrated a decreased R value postoperatively, with subsequent normalization. Other TEG measurements were equivalent to preoperative values. All procoagulant factors save factor VIII decreased postoperatively, with a simultaneous decrease in protein C.
  
  
  CONCLUSIONS
  TEG demonstrated a brief hypercoagulable state after major hepatectomy, with coagulation subsequently normalizing. The INR significantly overestimates hypocoagulability after hepatectomy and these data call into question current practices using the INR to guide therapy in this patient population.
authors.affiliation: Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA. Electronic address: louis@ohsu.edu.
authors.forename: Scott G
authors.initials: SG
authors.lastname: Louis
authors.affiliation: Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Barton
authors.affiliation: Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA.
authors.forename: Gordon M
authors.initials: GM
authors.lastname: Riha
authors.affiliation: Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Orloff
authors.affiliation: Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA.
authors.forename: Brett C
authors.initials: BC
authors.lastname: Sheppard
authors.affiliation: Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA.
authors.forename: Rodney F
authors.initials: RF
authors.lastname: Pommier
authors.affiliation: Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA.
authors.forename: Samantha J
authors.initials: SJ
authors.lastname: Underwood
authors.affiliation: Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA.
authors.forename: Jerome A
authors.initials: JA
authors.lastname: Differding
authors.affiliation: Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Schreiber
authors.affiliation: Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA.
authors.forename: Kevin G
authors.initials: KG
authors.lastname: Billingsley
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001778:Blood Coagulation Disorders / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D001779:Blood Coagulation Factors / Q000378:metabolism; D005260:Female; D006498:Hepatectomy; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods*; D011183:Postoperative Complications / Q000097:blood / Q000175:diagnosis*; D011446:Prospective Studies; D013916:Thrombelastography
chemical_list: D015415:Biomarkers; D001779:Blood Coagulation Factors
keywords: Coagulation; Hepatectomy; INR; Thrombelastography