There are many patients who need anticoagulation, such as lower extremity venous thrombosis after valve replacement in the next anticoagulation oral warfarin problem to do a description of the hope that can be helpful to the friends who have this need. 1, anticoagulation of many factors affecting what we should do? My suggestion is to respond to all changes with no change. The so-called unchanged is that the dose of warfarin should always be regulated according to the results of the INR value. As we all know, after valve replacement, INR value should be controlled between 1.8-2.5, below 1.8 should increase the dose of the drug, above 2.5 should decrease the dose of the drug, which is the general rule of warfarin regulation. Therefore, when you take the so-called “may affect the anticoagulation of food and drugs,” what to do, is to review the INR, according to the results of the decision on the dosage of warfarin. 2. What if the INR is significantly higher? Currently, the recommended standard of anticoagulation after valve replacement in China is to maintain the INR between 1.8 and 2.5. When the INR is greater than 2.5, adjustments can be made according to the specific value. Adjustments can be made by discontinuing warfarin, or by administering vitamin K1, or by transfusing fresh plasma and concentrated prothrombin preparations. Generally, the INR value can be significantly decreased after stopping warfarin for 4 to 5 days. In contrast, administration of vitamin K1 can result in a significant decrease in INR values within 24 hours. In general, the risk of bleeding increases only when the INR value is greater than 4, and the risk of bleeding increases significantly when the INR value is greater than 5. Even with excessively prolonged INR values, the absolute risk of bleeding remains low, so many physicians often manage patients with INR values as high as 5 to 10 by discontinuing warfarin unless the patient has high-risk qualities for bleeding or is already experiencing bleeding symptoms. Therefore, for patients with INR values greater than 2.5 and less than 3, it is important not to have any nervousness and to adjust the drug dose appropriately by discontinuing the drug once and rechecking the INR value every other day. However, patients with high INR values should also be treated seriously, and the following is a reproduction of the principles of management of increased INR in the anticoagulation guidelines published by the American College of Chest Physicians (ACCP). (1) When INR values are outside the therapeutic range but less than 5, and the patient is not bleeding from a clinically important site or undergoing surgery that requires rapid reversal of the INR value, warfarin may be reduced in dosage or discontinued. It is then reintroduced at a lower dose when the INR value approaches the desired range. (2) If the INR value is between 5 and 9, the patient is not bleeding, and there are no risk factors contributing to bleeding, warfarin may be discontinued for 1 to 2 days and then re-given in a smaller dose when the INR value falls into the therapeutic range. Give oral vitamin K1 (1 to 2.5 mg) and discontinue warfarin in patients at high risk for bleeding. (3) If emergency surgery or tooth extraction requires rapid reversal of the INR and the INR is expected to decrease within 24 hours, oral vitamin K12 to 5 mg can be given, with an additional 1 to 2 mg of vitamin K1 if the INR is still high after 24 hours. (4) If the INR is greater than 9, but is not associated with bleeding from a clinically important site, oral vitamin K13 to 5 mg and expect the INR to decrease within 24 to 48 hours, monitor the INR closely, and repeat oral vitamin K1 if necessary. (5) If rapid reversal of anticoagulation is required because of severe bleeding or warfarin overdose (INR >20), 10 mg of vitamin K1 should be given intravenously by slow infusion, and supplemented with fresh plasma or plasminogen complex concentrates, depending on the degree of urgency. Additional doses of vitamin K1 may be given every 12 hours if necessary. (6) In the event of life-threatening hemorrhage or severe warfarin overdose, prothrombin complex concentrate replacement therapy is necessary, with a slow intravenous injection of 10 mg of vitamin K1 as supplemental therapy, which may be repeated depending on the INR. If warfarin is to be reapplied after administration of high doses of vitamin K1, heparin should be given until the effects of vitamin K1 are reversed and the patient regains warfarin sensitivity. 3.What if bleeding occurs during anticoagulation? Depending on the degree of bleeding, patients can be categorized into minor bleeding and major bleeding. For minor bleeding, such as oral (gum) bleeding, nosebleeds, subcutaneous bruises or hematomas, subconjunctival bleeding, microscopic or hematuria, respiratory bleeding, menstrual bleeding or black stools, etc., the vast majority of the short-term reduction or suspension of the drug for 1 or 2 times after bleeding can be controlled and gradually absorbed, bleeding control can be restored to the therapeutic dose of the level of the INR value, the bleeding will not affect the continuation of treatment or lead to serious consequences. This kind of bleeding does not affect the continuation of treatment or lead to serious consequences. In addition, some patients reflected that the lower legs of both lower limbs are prone to purple spots, which may be related to the rupture of capillaries, I often recommend patients to take a small amount of vitamin C to improve the flexibility of the capillary wall, the efficacy of which needs to be further observed. For major hemorrhage, such as cerebral hemorrhage or severe internal bleeding, it is necessary to go to the hospital for rapid medication to terminate the anticoagulant effect of warfarin. For bleeding that occurs when the INR value is outside the therapeutic range, reintroduction of warfarin can be initiated as soon as the bleeding stops or the cause of the bleeding is corrected. For patients who are at risk of bleeding if the INR value is maintained within the therapeutic range, the INR value should be lowered to between 1.5 and 2.0 so that the anticoagulant effect is diminished but not lost. 4.What should I do if I want to do other surgeries after the anticoagulation period? First, decide the appropriate response according to the size of the surgery. If it is a tooth extraction or superficial surgery on the body surface, you can appropriately reduce the dose of warfarin, maintain the INR value at about 1.8 and then the surgery can be performed. After the surgery, pay attention to moderately increase the time of hemostasis by compression to avoid bleeding, and if necessary, you can apply tranexamic acid or aminoacetic acid to rinse the oral cavity to help stop bleeding. If it is a large operation or emergency surgery, the INR value should be reduced to 1.0~1.5 level as far as possible at the time of operation; since the patient is not allowed to have anticoagulation “vacuum” state, so it must be supplemented with low molecular heparin or heparin therapy. Generally, warfarin is stopped for 4-5 days before surgery, and low-dose heparin (5000U subcutaneous injection) or low molecular heparin is added until the early morning of the day of surgery. Second, warfarin dosing is resumed starting the evening after surgery with the addition of low-dose heparin or low-molecular heparin for at least 4-5 days, because it takes 3-7 days for anticoagulation to occur after warfarin is taken orally, and heparin or low-molecular heparin is discontinued after the target INR value is reached by monitoring the INR.