INR stands for "International Normalized Ratio" which is the ratio of the prothrombin time of the patient, and the prothrombin time reference in the normal individual. The PT is a test to identify the quality of blood
clotting, which depends on many factors, the main one being the prothrombin. Prothrombin is synthesized by the liver
in response to vitamin K
. Thus, vitamin K is used as an anticoagulation treatment to increase the fluidity of the blood. INR enables the determination of the effectiveness of anticoagulant
therapy with vitamin K antagonists (VKA). Specifically, when the ratio is 1, the anticoagulant effect is zero (this is the rate of a normal person, without treatment). Generally, the desired rate is located between 2 and 3, especially in the prevention of thromboembolic diseases
such as in cardiac atrial fibrillation
, or between 3 and 4 in patients at high risk, who have a heart valve, for instance. In case of an imbalance of treatment, the INR can rise to values higher than 4 and cause a risk of bleeding. Depending on the INR rate and the presence or absence of signs of bleeding, the treatment may vary from a simple dose adjustment to vitamin K antagonist
therapy administered in an emergency.
Original article published by
. Translated by Jeff
Latest update on December 11, 2013 at 04:42 AM by Jeff.