prothrombin time

(redirected from International normalized ratio)
Also found in: Dictionary, Thesaurus, Medical, Financial, Acronyms.
Related to International normalized ratio: INR

prothrombin time

[prō′thräm·bən ‚tīm]
(pathology)
A one-stage clotting test based on the time required for clotting to occur after the addition of tissue thromboplastin and calcium to decalcified plasma.
Mentioned in ?
References in periodicals archive ?
The influence of the reference mean prothrombin time on the international normalized ratio. Am J Clin Pathol.
Failure of the International Normalized Ratio to generate consistent results within a local medical community.
Enhanced standardization of the international normalized ratio through the use of plasma calibrants: a concise review [Review].
The international normalized ratio: a guide to understanding and correcting its problems.
Problems with the international normalized ratio. Blood.
Very close monitoring of the international normalized ratio (INR) is essential when initiating the binder.
The MELD score uses a mathematical formula based on serum creatinine levels, bilirubin levels, and international normalized ratio. A patient's score can range from 6 to 40.
Low-intensity warfarin (target international normalized ratio [INR], 1.5-2.0) effectively prevents recurrent venous thromboembolism without increasing the risk of major bleeding when used long-term for secondary prophylaxis.
Standardization of the prothrombin time (PT) with the International Normalized Ratio has been difficult, but the more complex PTT has not yet been standardized even to this extent.
Noting that data are scarce to guide clinicians in the dosing of warfarin for the elderly, the researchers assessed established dosing practices in two large cohorts of more than 12,000 ambulatory patients with international normalized ratio target ranges of 2.0-3.0.
Compared with aspirin alone, aspirin plus warfarin (goal for international normalized ratio, 2-2.5) or warfarin alone (goal for international normalized ratio, 2.8-4.3) results in fewer reinfarctions and thromboembolic events.
The geometric mean of the prothrombin times (PT) (5) of a reference sample group (mean normal prothrombin time, MNPT) is currently recommended as the denominator term in the expression of PT ratios and International Normalized Ratio (INR) values [1, 2].

Encyclopedia browser ?
Full browser ?