1, anticoagulant application duration: 3-6 months of anticoagulation after biological flap replacement, such as atrial fibrillation, huge left atrium can extend the anticoagulation time, mechanical flap replacement after lifelong anticoagulation. 2, anticoagulation standards and monitoring: anticoagulant drug dosage is insufficient, there is a risk of thrombosis, embolism, anticoagulant drug overdose, there is a risk of bleeding, the correct anticoagulation is very important. Insufficient or excessive anticoagulation can threaten your health and life! Normal values: prothrombin time (pt) 12-14 seconds; activity (pi) at 80% or more. The correct standard for anticoagulation is a pt of 1.5-2 times the normal value (21-28 seconds). Activity was between 35-50%. The international ratio (inr) is between 2.0 and 3.0. For proper anticoagulation, blood should be collected frequently for laboratory testing to adjust the dose of medication. During the period of figuring out the appropriate dosage (i.e., to find out the regular period of medication), the blood is usually tested once a day or every other day, after finding the regularity, it can be measured once a week, and if it is repeatedly measured many times, it can be measured once every 2-4 weeks, and the longest can be once every 3 months. 3, the adjustment of the dose: (1) the general first dose of warfarin 3-5mg, later adjusted according to the results of laboratory tests and the presence of signs of bleeding. (2)Insufficient anticoagulation: if the prothrombin time is lower than 1.5 times the normal value or activity > 60%, 1/4-1/8 of the maintenance dose can be added as appropriate; if the prothrombin time is close to normal, find the cause and re-anticoagulate. (3) anticoagulation overdose: if the prothrombin time is more than 2.5 times normal or activity is less than 25%, the dosage can be reduced by 1/4 a 1/8, if the activity is less than 20%, the dosage can be stopped once and adjusted after laboratory tests the next day, such as misuse (or repeated dosage), no bleeding tendency can be closely observed, there is a bleeding tendency on immediate injection of vitamin K1 against. And immediately contact with the hospital. (4) Pay attention to the presence of bleeding tendency, often manifested as epistaxis, gum bleeding, blood in urine, intra-abdominal bleeding manifested as abdominal pain, intracranial bleeding manifested as coma, etc. If there are signs of bleeding, the dose should be reduced or suspended even if the laboratory tests are in the appropriate range. And contact with the hospital immediately. (5) Pay attention to the presence of thrombosis and embolism: the cause of thrombosis is related to the valve material and structure in addition to insufficient anticoagulation, and thrombosis is manifested as valve acoustic changes and heart failure, such as cerebrovascular embolism with neurological symptoms: confusion, hemiparesis, etc. Limb artery embolism appears as limb pain. 4, anticoagulant maintenance dose: general maintenance warfarin in about 3mg/day, but due to individual differences, the required dose is different, clinical observation requires up to 7mg/day, the least only 0.5mg/day. Be sure to follow the cardiac surgeon’s orders for regular laboratory tests 5. Factors affecting drug dosage and monitoring results: (1) Drug effects: Drugs that enhance anticoagulation are as follows: a. Reduce intestinal production of vitamin K; broad-spectrum antimicrobial agents. b. Compete for plasma protein binding sites, increasing the proportion of drugs bound to protein at the end, aspirin, antomin, sulforaphane, and propofol. c. Decreases absorption of vitamin K; liquid paraffin, etc. d.Inhibits enzymes that degrade chemfacine: chloramphenicol, metronidazole, meclizine, disulfiram, alcohol. e.Competition for the same surrogate injection pathway: phenytoinamide, toluenesulfonylurea. f. Enhancing the action of a drug at its site of use or altering other coagulants: quinidine, anthromine, metformin, phenylephrine. g. Synergistic anticoagulant effects: aspirin, acetaminophen. h. Affecting platelet function: salicylates, pau d’arco, chlorpromazine, diphenhydramine. Decrease the anticoagulant effect of the following drugs: a. of the intestinal tract and anticoagulant drugs conjunctive whole: abciximide. b. Promote hepatic microsomal enzyme activity and accelerate the intrahepatic metabolism of warfarin: cataplexy, rifampin, ashwagandha. c. Increase the level of blood juxtaposition blood factors: estrogen, oral contraceptives. (2) The effect of food: foods rich in vitamin k can reduce the effectiveness of the drug. Vitamin k content per 100g of dry food (mg): spinach (4.40), cabbage (3.20), cauliflower (3.00), peas (2.80), carrots (0.80), tomatoes (0.40-0.80), potatoes (0.16), pig liver (0.80), eggs (0.80), buttermilk (trace). Long-term consumption of large amounts of the above foods should be timely laboratory tests to adjust the amount of falin. (3) The influence of disease diarrhea, vomiting can affect the absorption of drugs, liver stasis and liver disease in heart failure can reduce the synthesis of v-k, so that warfarin dosage is reduced. (4) Warfarin drug: pay attention to the expiration date of the drug, the dose per tablet (there are 3mg, 5mg dosage forms), whether the drug has dampness, mold, deterioration. (5) Blood collection time: whether the peak time is reached after taking the drug (after taking the drug). (6) Assay error: there is an error in the assay, if necessary, repeat the blood collection assay. Or at the same time draw normal human blood control. If there is a change in the test results, you should think of the above factors, and vice versa when applying drugs or changing the type of diet, you should also think of the effect of anticoagulation. Consult with your doctor in a timely manner. 6, the management of bleeding complications: (1) light bleeding: such as gum bleeding, skin bruising can be reduced according to the laboratory results of warfarin dosage 1/4-1/8. (2) obvious bleeding: such as epistaxis, hematuria can stop using warfarin for 1 or 2 days. (3) Severe bleeding: such as hemoptysis, vomiting blood, intracranial hemorrhage, immediate sedation of vitamin K 120mg, observation for 1-2 days after the bleeding stops, and re-anticoagulation. (4) Fresh frozen plasma or coagulation factor concentrates should be used in critical cases to supplement coagulation factors. (5) Do not forget to contact the surgical hospital. 7, anticoagulation during menstruation: most people do not have a lot of menstruation, the amount of anticoagulants used remains the same; if the bleeding increases, the amount of warfarin can be reduced, if there is a lot of bleeding, vitamin K can be injected to stop the bleeding, if the menstrual bleeding is disordered and the bleeding continues, menstrual regulating drugs should be taken; in very few cases of heavy bleeding, hysterectomy is required. 8, the treatment of surgery during anticoagulation: in order to surgery does not cause excessive blood loss, the following methods can be used: (1) non-stop anticoagulation: bleeding less or can be stopped by compression of minor surgery can be non-stop anticoagulation, such as removal of small masses on the body surface, debridement. (2) Maintenance of anticoagulation: anticoagulation can be postponed for those who have not started anticoagulation recently after surgery and need to perform emergency surgery, such as tracheotomy, no tendency to continue bleeding after emergency surgery, anticoagulation should be started as early as possible. (3) Suspend anticoagulation: When emergency surgery is required, blood should be taken immediately to measure prothrombin time and activity, and vitamin k 120mg should be injected sedately, and surgery can be performed 4 hours later after the prothrombin time is normal; if time is urgent, surgery can be started after vitamin k1 is injected sedently without waiting for the laboratory results, and anticoagulation should be started 24-48 hours after bleeding has stopped. (4) Suspension of anticoagulation: stop warfarin 3-5 days before surgery and operate after normal laboratory tests, or stop warfarin 5 days before surgery. Heparin injection, stop heparin 4-6 hours before surgery. 9, pregnancy: warfarin can enter the placenta, the first trimester of pregnancy to take warfarin risk of fetal malformation, heparin can not pass through the placenta, the first trimester of pregnancy to stop warfarin, heparin subcutaneous injection. However, there are reports in the literature of normal babies born on warfarin. If the pregnancy is not suitable to continue, abortion is feasible, see 8 for pre- and post-operative treatment. 10, perinatal anticoagulation: (1) change warfarin to heparin 1-2 weeks before the expected date of delivery, postpartum, such as bleeding with fisetin to counteract, 24-48 hours after delivery of the fetus without signs of bleeding, start oral warfarin. (2) No stopping warfarin, injecting vitamin K1 after contractions start, and starting anticoagulation 24-48 hours after delivery of fetus without bleeding signs. (3) Cesarean section.