international normalized ratio


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Related to international normalized ratio: INR

international normalized ratio (INR),

the prothrombin time ratio that would have been obtained if a standard reagent had been used in a prothrombin time determination; the prothrombin time ratio is expressed as the patient prothrombin time divided by the mean of the prothrombin time reference interval; the prothrombin time ratio is obtained for a working reagent in the laboratory through use of a parameter designated the international sensitivity index. Compare: international sensitivity index.

international normalized ratio

(ĭn′tər-năsh′ə-nəl)
n.
A standardized measure of the clotting ability of blood based on the ratio of an individual's prothrombin time to the normal mean prothrombin time, used especially to monitor the risk of bleeding in patients receiving anticoagulant therapy.

International Normalized Ratio (INR)

a comparative rating of a patient's prothrombin time (PT) ratio, used as a standard for monitoring the effects of warfarin. The INR indicates what the patient's PT ratio would have been if measured by using the primary World Health Organization International Reference reagent.

International Normalized Ratio

Hematology A method of reporting prothrombin time–PT results for Pts receiving oral anticoagulant therapy; the INR is defined by the formula, PTPatient/PTMNPTISI that uses the international sensitivity index to adjust PT results from thromboplastin of different sources and facilitates monitoring anticoagulant therapy when using more than one lab and comparing a Pt's PT results with published standards for treatment. See Anticoagulation, International sensitivity index, Prothrombin time.

in·ter·na·tion·al nor·mal·ized ra·ti·o

(INR) (in'tĕr-nash'ŭn-ăl nōr'măl-īzd rā'shē-ō)
The prothrombin time ratio that would have been obtained if a standard reagent had been used in a prothrombin time determination; the prothrombin time ratio is expressed as the patient's prothrombin time divided by the mean of the prothrombin time reference interval; the prothrombin time ratio is obtained for a working reagent in the laboratory through use of a parameter designated the international sensitivity index.
See also: international sensitivity index

INR

; international normalized ratio index of blood coagulability (normal INR = 1); anticoagulant therapy (e.g. warfarin) adjusts INR to 2-4 (i.e. anticoagulated blood takes twice to four times as long to clot)
References in periodicals archive ?
Moreover, the effects of warfarin last for an average of three days after the last dose, so the international normalized ratio may continue to increase following treatment with tPA.
Comparison of Participant Performances Assessed by Using International Normalized Ratio (INR) and Prothrombin Time (PT) Ratio (n = 121) * Sample October 2006 Consensus INR PT Ratio Outwith, No.
In a previous report in Clinical Chemistry, we described much higher international normalized ratios (INRs) [1] with recombinant Neoplastin R (Roche Diagnostics) than with tissue-extract Neoplastin Plus (Roche Diagnostics) in patients initiating oral anticoagulant therapy (1).
Inaccuracy of international normalized ratio (INR) measurements and suggestions for improved WHO guidelines for calibration of reference preparations; a statistical study.
Therefore, every physician should be aware of possible drug-herb interactions especially in patients on warfarin who experience excessive bleeding or unexpected prolongation of international normalized ratio and who have previously been under good anticoagulant control.
About the Alere INRatio2 PT/INR Professional Monitoring System The Alere INRatio2 PT/INR Professional Monitoring System, consisting of the Alere INRatio2 PT/INR Monitor and the Alere INRatio2 PT/INR Professional Test Strip, is intended for use in the quantitative determination of International Normalized Ratio (INR) in fresh capillary whole blood to monitor the effect of warfarin on clotting time by health care professionals.
For patients taking warfarin, weekly at-home self-testing of international normalized ratio is no better than high-quality monthly clinic INR testing at preventing major adverse events, according to a new report.
Is the international normalized ratio also 'valid' for prothrombin times measured in patients not receiving oral anticoagulants?
5%, a platelet count of 376, and an international normalized ratio (INR) of 9.
International Normalized Ratio (INR) is the standard unit for reporting the clotting time of blood, which must be tested on a regular basis in order for a person on anticoagulants to remain in his or her prescribed "range" For those with chronic atrial fibrillation or venous thromboembolism, it can mean monthly trips to the physician, clinic or lab for blood work, which imposes a tremendous burden on both the patient and the physician.
WARNING : Ingestion of more than 3 grams of omega-3 fatty acids per day has been shown to have potential antithrombotic effects, including an increased bleeding time and international normalized ratio (INR).
Also, there is considerable doubt as to whether control patients were equally managed post intervention, and there were no data on the international normalized ratio achieved.

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