title: Reliability of a point-of-care device for international normalized ratio testing during the three surgical phases of orthotopic liver transplantation: a retrospective observational study.
abstract: OBJECTIVE
  To investigate the reliability of a point-of-care device, the HEMOCHRON(®) Jr. Signature, for measuring the international normalized ratio (INR) during the three surgical phases of liver transplantation.
  
  
  METHODS
  A retrospective review was performed on patients undergoing liver transplantation during July to December 2013. Thirty-one patients who had simultaneous laboratory and point-of-care INR readings from each phase of liver transplant surgery (paleohepatic, anhepatic, and neohepatic) were eligible for inclusion. Bland-Altman analysis, Spearman's rank correlation, and four quadrant plots were used to compare INR results from the point-of-care device (pocINR) with those from the laboratory (labINR).
  
  
  RESULTS
  Based on the Bland-Altman analysis, mean biases (95% prediction interval) were 0.10 (0.03 to 0.17), 0.19 (0.12 to 0.27), and 0.21 (0.01 to 0.43) for the paleohepatic, anhepatic, and neohepatic phases, respectively. The pocINR device showed a systematic underestimation of the labINR. The Spearman's rank correlation coefficients (95% confidence interval [CI]) were: Ρ = 0.90 (95% CI 0.80 to 0.95); Ρ = 0.92 (95% CI 0.71 to 0.93); and Ρ = 0.71 (95% CI 0.46 to 0.85), respectively. Direction-of-change analysis between the paleohepatic to anhepatic and the anhepatic to neohepatic phases showed strong concordance of 84% and, also considering the small bias between the measurements, supports the use of the pocINR device in the clinical management of liver transplant surgery.
  
  
  CONCLUSIONS
  Point-of-care INR was accurate prior to hepatic reperfusion, but reliability decreased in the neohepatic phase.
authors: Hepatobiliary and Transplant Anesthesia, Toronto General Hospital, University Health Network, Toronto, ON, Canada.
authors: Hamish S
authors: HS
authors: Mace
authors: Nicholas J
authors: NJ
authors: Lightfoot
authors: Maria-Jose
authors: MJ
authors: Cordero-Rochet
authors: Coimbatore
authors: C
authors: Srinivas
authors: Keyvan
authors: K
authors: Karkouti
authors: Stuart A
authors: SA
authors: McCluskey
mesh_terms: D005260:Female; D006801:Humans; D019934:International Normalized Ratio / Q000295:instrumentation*; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems; D015203:Reproducibility of Results; D012189:Retrospective Studies