INR examination
The INR, the so-called prothrombin time, is a test based on measuring the external factors of blood clotting or blood-clotting. Therefore, the doses of drugs used to prevent blood clotting are measured or determined, such as liver damage and varicose veins, The condition of vitamin K; the time of the prothrombin is to measure the factors in the coagulation of the blood, namely: (Factor I, Factor II, V, VII, and factor X), and used this test in addition to the partial time of active thermoplastin, which measures the factors of internal clotting.
The normal level of the international print ratio is 0.8-1.2. Most doctors aim at a higher rate than the international typographic ratio in most cases (2.5) , When some cases require the use of anticoagulants such as warfarin.
As for the common method of measuring prothrombin, blood plasma is used by taking a blood sample and placing it in the test tube, which contains a quantity of liquid cysts that act as anticoagulant when combined with the calcium in the blood, The sample is subjected to centrifugal force for separation of blood cells and plasma.
Plasma is often analyzed by a biomedical scientist through a machine to set the sample temperature to 37 ° C, where the plasma is, then the calcium is added to the blood clot again, and there are some controls for accurate measurement, With some of the laboratories refusing to perform the examination if the tube is not filled with blood.
In terms of results, prothrombin time is the time taken by the plasma to clot after the tissue factor is added and obtained from animals. It is based on measuring the quality of the external factors of the clotting process. There are some factors that determine the accuracy of the analysis of the results, : “Lupus factor”, which works to prevent the factors that lead to clotting when the blood flow, resulting in inaccuracies in the results, depending on the method and method of analysis used.
In the past, there was a decline in the accuracy of readings of the international print ratio because of the difference in thromboplastin preparation, but in 2005 a study was done on the international print ratios for differences in test results, but the accuracy and reliability of the INR test for international printing is questioned as a procedure To measure the effect of anticoagulation.