I. People who need anticoagulation for valve replacement 1. Biological valve replacements require short-term anticoagulation for about 6 months; 2. Mechanical valve replacements must have lifelong anticoagulation. Types of anticoagulant drugs There are four main types of anticoagulant drugs currently used after valve replacement: 1) coumarins: warfarin; 2) antiplatelet drugs: pansentin, aspirin, etc.; 3) heparin/low molecular heparin; 4) prothrombin inhibitors: similartan. Warfarin is currently recognized as the anticoagulant of choice after prosthetic valve replacement. The pharmacological effects of warfarin Warfarin is a vitamin K antagonist, which exerts anticoagulant effects by hindering the synthesis of four coagulation factors, II, VII, IX and X, in which vitamin K is involved. The anticoagulant effect of warfarin can be maintained for 3-4 d. After stopping the drug, the coagulation function will be gradually restored after many days with the synthesis of new active coagulation factors. Fourth, the method of warfarin administration Warfarin administration has two kinds of maintenance dosing method and saturation dosing method. The former is the most widely used for patients who do not need emergency anticoagulation, for 1-2 days after surgery, drainage flow is significantly reduced or after the removal of the drainage tube oral warfarin anticoagulation, starting with a small daily dose (2.5-3mg), 2-3 days later according to the test results to adjust the amount of medication, generally 7-14 days to achieve stable anticoagulation effect. V. Anticoagulation monitoring and standards The prothrombin time (PT) is the most commonly used monitoring method for warfarin anticoagulation, but there are many factors affecting the PT test process, and the test should be repeated several times if necessary. 1982, the World Health Organization recommended the use of the International Sensitivity Index (ISI) to correct the PT value, and the result is called the International Standard Ratio (INR), and in 1985, the International Society for Thrombosis and Anticoagulation and the International Blood Standards In 1985, the International Society for Thrombosis and Anticoagulation and the International Blood Standards Association jointly required that the PT report must be accompanied by an INR result. Currently, most scholars in China believe that the anticoagulation standard in China is lower than that in Europe and the United States. The PTR/INR of anticoagulation after mechanical valve replacement should be controlled between 1.5 and 3.0. VI. Factors affecting the anticoagulation effect and treatment strategies 1. influence of drugs (1) enhancing effect: alcohol, pautazone, chloral hydrate, diuretic acid, allopurinol, cimetidine, steroids (steroids), anti-inflammatory pain, quinidine, salicylate, thyroxine, methotrexate, chloramphenicol, sulfonamide, metronidazole, diuretic acid, amiodarone, omeprazole, acetaminophen, heparin, hyperglycemia, etc. (2) Hypotensive effects: vitamin K, sleeping pills, estrogen, oral contraceptives, rifampin, ashwagandha, etc. 2, the effect of diet The patient’s postoperative diet can interfere with the anticoagulant effect of coumarin drugs, but not directly, generally very little interference. Early postoperative period, the systemic condition improved, liver function returned to normal, after the increase in stomach stomach a stage should often increase the amount of medication, especially often eat spinach, green vegetables, tomatoes, cauliflower, fresh peas and other vegetables in larger amounts, or often eat more meat such as pork liver, or fruit, because these side food crystals contain more vitamin K, can make the prothrombin time is reduced. However, after the stage of anticoagulant dose adjustment, the effect of diet on anticoagulation is not important in normal diet and lifestyle habits.