history of the prothrombin time and development of the inr
DESCRIPTION
European Concerted Action on Anticoagulation. History of the Prothrombin Time and Development of the INR. Leon Poller. Mean results with different thromboplastins in 30 patients. Poller L. Acta Haemat. 32:292-298 (1964). Mean doses of warfarin from different geographical locations. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/1.jpg)
History of the Prothrombin Time and Development of the INR
Leon Poller
European Concerted Action on Anticoagulation
![Page 2: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/2.jpg)
Mean results with different thromboplastins in 30 patients
Poller L. Acta Haemat. 32:292-298 (1964)
![Page 3: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/3.jpg)
Mean doses of warfarin from different geographical locations.
Striped boxes indicate rabbit reagent.
![Page 4: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/4.jpg)
Bleeding events with Simplastin (ISI 2.5) and Manchester Reagent (ISI 1.0) control.
Hull et al (1982). Prothrombin Ratio 2.0 Simplastin = 4.7 INR.
![Page 5: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/5.jpg)
![Page 6: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/6.jpg)
![Page 7: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/7.jpg)
Figure 1 Figure 2
![Page 8: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/8.jpg)
![Page 9: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/9.jpg)
![Page 10: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/10.jpg)
ACCP Consensus Meeting
![Page 11: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/11.jpg)
An example of the orthogonal regression line
![Page 12: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/12.jpg)
Calibration lines from the seventeen participant centres
![Page 13: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/13.jpg)
The hierarchical structure of thromboplastin calibration
![Page 14: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/14.jpg)
IRP = International Reference Preparation. *Now discontinued.
IRR = International Reference Reagent. IS = International Standard.
International reference preparations for thromboplastins 2003
![Page 15: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/15.jpg)
INR = Prothrombin Ratio (PR)ISI
![Page 16: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/16.jpg)
Causes of Erroneous INRs (1)
• Pretest variablesErroneous prothrombin ratio determination
Variations in manual techniqueCoagulometer effects
• Incorrect normal value due to: Failure to use MNPT Error in MNPT due to: (a) unrepresentative selection; (b) technical faults; (c) non-use of geometric mean.
![Page 17: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/17.jpg)
Causes of Erroneous INRs (2)
• Incorrect ISI calibration • Drift of ISI • Poor distribution of coumarin test samples,
inadequate numbers of test samples• Incorrect choice of IRP • Incorrect transformation of PR to INR
• ‘Rogue’ plasmas (outliers)
![Page 18: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/18.jpg)
Errors in PT Determination • Pretest variables • blood collection • citrate • container • storage time • temperature • evacuated and non-evaculated tubes • variations in manual technique • coagulometers The overall trend of coagulometers is to accelerate the normal PT
with the PR distorted.System-related ISI of limited value.
![Page 19: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/19.jpg)
Coagulometer Effects of ACL and MLA
![Page 20: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/20.jpg)
The ISI of thromboplastins and effect of ISI on the width of therapeutic range in prothrombin ratios.
![Page 21: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/21.jpg)
Percentage deviation of mean INR from the IRP value with various thromboplastin reagents during the
induction phase
Reagent C
Reagent B
Reagent A
Reagent D
![Page 22: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/22.jpg)
![Page 23: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/23.jpg)
![Page 24: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/24.jpg)
![Page 25: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/25.jpg)
![Page 26: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/26.jpg)
Reliability of monitor INR on CoaguChek Mini and TAS PT-NC at 10
centres
No. of samples
Displayed INR
“true” INR
% difference
Mean displayed
INR difference
TAS PT-NC 536 2.91 2.52 +15.2
21.3
CoaguChek Mini
536 2.40 2.59 -7.1
Br Med J 2003;327:30-34
![Page 27: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/27.jpg)
DAILY TELEGRAPH 23 SEPTEMBER 2003
![Page 28: History of the Prothrombin Time and Development of the INR](https://reader036.vdocuments.us/reader036/viewer/2022081503/56814a9d550346895db7ac2c/html5/thumbnails/28.jpg)
Proportion of time in INR ranges
*INR results for all weeks, including first 3 weeks
Lancet 1998;352:1505-9