scholarly journals Extreme Elevation of the Prothrombin Time-International Normalized Ratio due to a Probable Interaction between Warfarin and Flutamide

2019 ◽  
Vol 58 (22) ◽  
pp. 3251-3253 ◽  
Author(s):  
Yasunobu Konishi ◽  
Takafumi Terada ◽  
Yoshimori Araki ◽  
Osamu Kawaguchi
Keyword(s):  
Prothrombin Time ◽  
International Normalized Ratio ◽  
Probable Interaction

Calibration of a Lyophilized Pooled Plasma as Candidate Reference Plasma for Standardization of the Prothrombin Time Ratio

1993 ◽  
Vol 13 (02) ◽  
pp. 96-105 ◽  
Author(s):  
H. Beeser ◽  
U. Becker ◽  
H. J. Kolde ◽  
E. Spanuth ◽  
P. Witt ◽  
...  
Keyword(s):  
Prothrombin Time ◽  
International Study ◽  
International Normalized Ratio ◽  
Measurement Methods ◽  
Factor V ◽  
Diagnostic Instruments ◽  
Plasma Pool ◽  
Normal Plasma ◽  
German Association ◽  
Prothrombin Time Ratio

SummaryThe prothrombin time (PT), obtained from a fresh normal plasma pool (FPP), is the basis both for the establishment of the 100% activity (normal plasma) and for the ratio calculation used in the International Normalized Ratio (INR) according to the recommendations of the ICSH/ICTH (6). Today the PT of lyophilized normal plasma pools are successfully used as reference for the assessment of samples in proficiency studies. However, a lack of comparability is to be recognized. Therefore the Committee of Hematology of the German Association of Diagnostics’ and Diagnostic Instruments’ Manufacturers (VDGH) decided to produce a candidate reference plasma (VDGH Reference Plasma) which was calibrated against fresh normal plasma pools in an international study.The basic calibration was performed by using the same certified BCR thromboplastin (BCT/099) by all participants. The endpoint was determined manually and by using the coagulometer Schnitger-Gross. In additional testings each participant used his own routine thromboplastins and methods. Calculating the ratio [PT VDGH Reference Plasma (sec)/PT fresh normal plasma pool (sec)] the VDGH Reference Plasma showed a deviation from the average fresh normal plasma pool of 1.05 both with the BCT/099 and with all thromboplastins. There were obtained some statistical differences between “plain” and “combined’’ (added factor V and fibrinogen) thromboplastins. No statistical difference was found between the different endpoint measurement methods (manual, mechanical, optical).In spite of these statistical deviations the VDGH Reference Plasma can be used for the standardization of the PT-normal (100%) value with different ratios for plain (1.06) and combined (1.02) thromboplastins. The manufacturers will use this VDGH Reference Plasma for the calibration of their commercially available calibration plasmas, which allows the user of such a material to calculate a calibrated 100% PT value.

scholarly journals The effect of vitamin K on prothrombin time in critically ill patients: an observational registry study

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sofia Dahlberg ◽  
Ulf Schött ◽  
Thomas Kander
Keyword(s):  
Propensity Score ◽  
Prothrombin Time ◽  
Critically Ill ◽  
Vitamin K ◽  
Critically Ill Patients ◽  
International Normalized Ratio ◽  
University Hospital ◽  
Red Blood Cell Transfusion ◽  
Registry Study ◽  
Exclusion Criteria

Abstract Background Previous studies have indicated that vitamin K deficiency is common in non-bleeding critically ill patients with slightly prolonged prothrombin time-international normalized ratio (PT-INR). It has never been investigated thoroughly whether the administration of vitamin K to these patients could affect their PT-INR. Therefore, the aim of this registry study was to evaluate changes in PT-INR in response to vitamin K in critically ill patients with PT-INR in the range of 1.3–1.9. Methods Patients admitted to a mixed 9-bed general intensive care unit at a University Hospital, between 2013 and 2019 (n = 4541) with a PT-INR between 1.3 and 1.9 at any time during the stay were identified. Patients who received vitamin K with appropriate sampling times for PT-INR and without exclusion criteria were matched with propensity score to patients from the same cohort who did not receive vitamin K (controls). PT-INR was measured at admission, within 12 h before vitamin K administration and 12–36 h following vitamin K administration. Exclusion criteria included pre-existing liver cirrhosis, any plasma or platelet transfusion, or > 1 unit red blood cell transfusion between PT-INR samplings. Results Propensity score matching resulted in two groups of patients with 129 patients in each group. PT-INR decreased in both groups (1.4 [1.3–1.4] in the vitamin K group and 1.4 [1.3–1.6] in the controls, p < 0.001 and p = 0.004, respectively). The decrease in PT-INR was slightly more pronounced in patients who received vitamin K (delta PT-INR − 0.10 [− 0.30 to − 0.10] in the vitamin K group and − 0.10 [− 0.20 to 0.10] in the controls, p = 0.01). Conclusion In critically ill patients with a PT-INR of 1.3–1.9, the administration of vitamin K resulted in a slightly larger decrease of PT-INR 12–36 h after administration compared to controls. Future studies should focus on identifying which patient populations may benefit most from vitamin K administration as well as whether vitamin K could be a better alternative than plasma or prothrombin complex concentrate to improve PT-INR before non-emergent invasive procedures.

A modified international normalized ratio as an effective way of prothrombin time standardization in hepatology

Hepatology ◽  
2007 ◽  
Vol 46 (2) ◽  
pp. 528-534 ◽  
Author(s):  
Laurent Bellest ◽  
Valérie Eschwège ◽  
Raoul Poupon ◽  
Olivier Chazouillères ◽  
Annie Robert
Keyword(s):  
Prothrombin Time ◽  
International Normalized Ratio

Outpatient Use of a Portable International Normalized Ratio/Prothrombin Time Monitor

1994 ◽  
Vol 87 (2) ◽  
pp. 206-210 ◽  
Author(s):  
RICHARD H. WHITE ◽  
DANIEL M. BECKER ◽  
MICHAEL G. GUNTHER-MAHER
Keyword(s):  
Prothrombin Time ◽  
International Normalized Ratio

scholarly journals Factors That Determine the Prothrombin Time in Patients With Atrial Fibrillation Receiving Rivaroxaban

2018 ◽  
Vol 24 (9_suppl) ◽  
pp. 188S-193S
Author(s):  
Jen-Hung Huang ◽  
Yung-Kuo Lin ◽  
Cheng-Chih Chung ◽  
Ming-Hsiung Hsieh ◽  
Wan-Chun Chiu ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Prothrombin Time ◽  
Factor Xa ◽  
International Normalized Ratio ◽  
Biochemical Properties ◽  
Study Patient ◽  
Group 3 ◽  
Multiple Variables ◽  
Group 2 ◽  
Group 1

Rivaroxaban, a direct factor Xa inhibitor, is widely used to reduce the chance of stroke in patients with atrial fibrillation (AF). It is not clear why the prothrombin time (PT) of the international normalized ratio (INR) fails to correlate with treatment using rivaroxaban in patients with AF. In this study, patient characteristics, the rivaroxaban dosage, AF type, drug history, biochemical properties, and hematological profiles were assessed in patients treated with rivaroxaban. In 69 patients with AF receiving rivaroxaban, 27 (39.1%) patients had a normal INR (≤1.1, group 1), 27 (39.1%) patients had a slightly prolonged INR (1.1∼1.5, group 2), and 15 (21.7%) patients had a significantly prolonged INR (>1.5, group 3). Group 1 patients had a higher incidence of a stroke history than did patients in group 2 ( P = .026) and group 3 ( P = .032). We scored patients with a persistent AF pattern (1 point), paroxysmal AF pattern (0 point), renal function (ie, the creatinine clearance rate in mL/min/1.73 m2 of >60 as 0 points, of 30∼60 as 1 point, and of <30 as 2 points), and no history of stroke (1 point), and we found that group 3 had a higher score than groups 2 or 1 (2.9 ± 0.8, 2.4 ± 0.7, and 2 ± 0.7, respectively; P < .05). There were similar incidences of bleeding, stroke, and unexpected hospitalizations among the 3 groups. The PT of the INR is determined by multiple variables in patients with AF receiving rivaroxaban. Rivaroxaban-treated patients with AF having different INR values may have similar clinical outcomes.

scholarly journals ASSESSMENT OF COAGULATION PROFILE IN PATIENTS WITH LIVER CIRRHOSIS AND ATRIAL FIBRILLATION

2021 ◽  
Vol 121 (1) ◽  
pp. 22-31
Author(s):  
Alіna Baylo ◽  
Vadym Shypulіn ◽  
Volodymyr Chernyavskyi ◽  
Luiza Parunyan
Keyword(s):  
Atrial Fibrillation ◽  
Liver Cirrhosis ◽  
Prothrombin Time ◽  
Partial Thromboplastin Time ◽  
International Normalized Ratio ◽  
Activated Partial Thromboplastin Time ◽  
Fibrinolytic System ◽  
Thrombin Time ◽  
Group I ◽  
D Dimer

The comorbid course of liver cirrhosis and atrial fibrillation causes higher levels of hospitalizations, mortality and ischemic stroke. According to current data, hemostasis in patients with liver cirrhosis is in a rebalanced dynamic state, but there are no data on the effect of atrial fibrillation on the hemostasis in patients with liver cirrhosis. Aims of the study. To assess abnormalities in primary, secondary haemostasis and fibrinolytic system in patients with liver cirrhosis and atrial fibrillation by using standard laboratory coagulation parameters and to investigate their changes depending on the stage of liver cirrhosis A, B, C according to Child-Pugh score. Materials and methods. A cross-sectional prospective study was conducted with the inclusion of 106 patients aged 42 to 83 years: group I (n = 70) - with liver cirrhosis and atrial fibrillation, II (n = 36) - with liver cirrhosis, which were distributed depending on the Child-Pugh score stages of cirrhosis and 20 healthy individuals. The levels of platelets, activated partial thromboplastin time, international normalized ratio, prothrombin time, thrombin time, fibrinogen, D-dimer were assessed on a Steellex M200 coagulometer. Statistical analysis (IBM SPSS Statistics) was performed. Results. The level of platelets in patients of group I was reduced by 37.4% (200 ± 8.33 vs. 274.7 ± 3.4; p,000.001), an activated partial thromboplastin time was prolonged by 38.6% (44.35 ± 1.39 vs. 32.01 ± 0.63, p˂0.001), prothrombin time was prolonged by 73.5% (19.4 ± 0.87 vs. 11.18 ± 0.53, p˂0.001), thrombin time was prolonged by 2.07 (25, 7 ± 1.31 vs. 12.4 ± 0.66, p˂0.001), the international normalized ratio was increased by 24.3% (1.38 ± 0.04 vs.1.11 ± 0.01, p˂0.001) compared to control. The fibrinogen level was 20.9% higher (4.17 ± 0.17 vs. 3.45 ± 0.11, p˂0.001) than in control group and was 83.7% higher (4.17 ± 0.17 vs. 2.27 ± 0.13, p˂0.001) than in group II. The D-dimer level was 83% higher than in control (675 ± 22.3 vs. 368.8 ± 21.85, p˂0.001) and 44% higher (675 ± 22.3 vs. 469 ± 37.18, p ˂0.001) compared with group II. Conclusions. In patients with liver cirrhosis and atrial fibrillation abnormalities of primary hemostasis are detected due to decrease of platelets on the background of portal hypertension. At the secondary stage of hemostasis indicators of external and internal coagulation mechanisms are prolonged due to the reduced synthesis of coagulation factors by the liver. Increased level of fibrinogen is determined at the stage of compensated and subcompensated cirrhosis with a gradual decrease at the stage of decompensation. The high activity of the fibrinolytic system is observed due to increase in the D-dimer levels, which may indicate a prothrombotic state in these patients.

scholarly journals Monitoring "mini-intensity" anticoagulation with warfarin: comparison of the prothrombin time using a sensitive thromboplastin with prothrombin fragment F1+2 levels

Blood ◽  
1992 ◽  
Vol 79 (8) ◽  
pp. 2034-2038 ◽  
Author(s):  
MM Millenson ◽  
KA Bauer ◽  
JP Kistler ◽  
S Barzegar ◽  
L Tulin ◽  
...  
Keyword(s):  
Prothrombin Time ◽  
Factor Xa ◽  
High Sensitivity ◽  
International Normalized Ratio ◽  
Target Range ◽  
Lower Sensitivity ◽  
Sensitivity Index ◽  
Plasma Samples ◽  
Prothrombin Activation

Treatment with warfarin using a target International Normalized Ratio (INR) range of 1.7 to 2.5 is efficacious for many clinical indications, but the minimal intensity of anticoagulation required for antithrombotic protection has yet to be determined. To evaluate whether patients could be reliably monitored with a less intense regimen, we anticoagulated patients with warfarin for several months using a target INR range of 1.3 to 1.6 as determined by prothrombin time (PT) using a sensitive thromboplastin (Dade IS, International Sensitivity Index [ISI] = 1.3). Plasma measurements of F1+2, a marker of factor Xa action on prothrombin in vivo, were also obtained to determine the suppressive effect of warfarin on hemostatic system activity. Overall, 20 of 21 patients with a history of cerebrovascular events (mean age, 61 years) could be reliably regulated with warfarin in the target INR range. F1+2 levels were significantly suppressed from baseline in all patients, with a mean reduction of 49% (range, 28% to 78%). We found a significant relationship between the extent of suppression of prothrombin activation levels and the baseline measurements. A mean reduction of 65% was observed for those patients with baseline F1+2 greater than or equal to 1.5 nmol/L, but only 38% for baseline F1+2 less than or equal to 0.5 nmol/L. Overall, 68% of plasma samples obtained during stable anticoagulation were within the target INR range. PTs were also determined on all plasma samples with two thromboplastins of lower sensitivity (C+, ISI = 2.09; and automated simplastin, ISI = 2.10). Only 47% and 35% of PT determinations, respectively, were within the target range with these reagents. We conclude that prothrombin activation can be significantly suppressed in vivo with use of warfarin in an INR range of 1.3 to 1.6. This level of anticoagulation can be reliably achieved by monitoring PTs with a thromboplastin of high sensitivity.

Sign in / Sign up

Export Citation Format

Share Document