Duration of anticoagulant application Anticoagulation for 3-6 months after biologic valve replacement, with appropriate prolongation in case of atrial fibrillation, giant left atrium. Lifelong anticoagulation is required after mechanical valve replacement. Anticoagulation criteria and monitoring Inadequate anticoagulation carries the risk of thrombosis and embolism, and overdose of anticoagulants carries the risk of bleeding; 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) above 80%. The correct standard for anticoagulation is a PT of 1.5 to 2 times the normal value (18-25 seconds). Activity is between 35 and 50%. The International Ratio (INR) is around 2.0. In order to properly anticoagulate, blood tests should be taken frequently to adjust the dosage. During the period of searching for the proper dosage (i.e., during the period of finding out the regularity of the dosage), the blood test is usually conducted once a day or every other day, and after finding out the regularity, the blood test can be conducted once a week, and if the repeated measurements are very stable, the blood test can be conducted once every 2-4 weeks, or once every 3 to 6 months in the longest period of time. Adjustment of dosage (1) Generally, the first dose of warfarin is 3-5mg, and then it will be adjusted according to the results of laboratory tests and whether there are signs of bleeding. (2)Insufficient anticoagulation: if the prothrombin time is lower than 1.5 times of normal value or the activity is >60%, 1/4-1/8 of the maintenance dose can be added as appropriate; if the prothrombin time is close to normal, the cause should be found and anticoagulation should be resumed. (3)Anticoagulation overdose:If the prothrombin time is more than 2.5 times of normal or the activity is lower than 25%, the dosage can be reduced by 1/4-1/8, such as the activity is low 20%, it can be discontinued once, and then adjusted after the next day’s laboratory test, such as mistakenly served (or repeated medication), no bleeding tendency can be closely observed, and if there is a tendency to bleed, it will be injected with vitamin K1 immediately to fight. And immediately contact the hospital. (4) Pay attention to whether there is bleeding tendency, often manifested as epistaxis, bleeding gums, blood in urine, intra-abdominal hemorrhage manifested as abdominal pain, intracranial hemorrhage manifested as coma and so on. If there is any sign of bleeding, the dosage should be reduced or suspended even if the laboratory test is in the appropriate range. And contact the hospital immediately. (5) Pay attention to the presence of thrombosis and embolism: the cause of thrombosis in addition to insufficient anticoagulation is still related to the valve material, structure, thrombosis manifested as valve sound changes, heart failure, such as cerebrovascular embolism neurological symptoms: confusion, hemiplegia, and so on. Limb arterial embolism may cause pain in the limbs. Anticoagulant maintenance dose General maintenance warfarin in 3mg / day, but due to individual differences, the required dose is different, clinical observation of up to 7mg / day, the least only 0.5mg / day. Make sure to have regular PT and INR tests as ordered by the cardiac surgeon. Factors affecting drug dosage and monitoring results (1) Drug effects: Drugs that enhance anticoagulation are as follows: A. Reduces intestinal production of vitamin K; broad-spectrum antimicrobials. B. Competition for plasma protein binding sites, so that the end of the proportion of protein-bound drugs increased, aspirin, Antomin, sulfonamide, probenecid. C. Decreases absorption of vitamin K; liquid paraffin, etc. D. Inhibits enzymes that degrade chemo-falcons: chloramphenicol, metronidazole, mephedrone, disulfiram, alcohol. E. Competition for the same vicarious route of emission: phenytoinna, toluene sulfobutylurea. F. Enhancement of their action or alteration of other coagulants at the site of drug administration: quinidine, antomin, metronidazole, phenelzine. G. Synergistic anticoagulant effects: aspirin, acetaminophen. H. Influence on platelet function: salicylates, prednisone, chlorpromazine, phenelzine. Drugs that reduce anticoagulant effects are as follows: A. of the intestinal tract with anticoagulant conjugation of the whole: cholestyramine. B. Promote hepatic microsomal enzyme activity and accelerate the intrahepatic metabolism of warfarin: hypnotics, rifampicin, ashwagandha. C. Elevate the level of juxtaglobin in the blood: estrogen, oral contraceptives. (2) Effect of food: Foods rich in vitamin K can reduce the efficacy 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), cow’s milk (trace). Long-term large quantities of the above foods should be promptly laboratory adjusted farin dosage. (3) The effect of disease: diarrhea, vomiting can affect the absorption of drugs, liver stasis in heart failure and liver disease all make V-K synthesis reduced, so that the dosage of warfarin reduced. (4) Warfarin drugs: pay attention to the expiration date of the drug, the dose of each tablet (3mg, 5mg two types of dosage), the drug has no deliquescence, mold, deterioration. (5) Blood collection time: whether the peak time is reached after taking the drug (after taking the drug). (6) Laboratory error: there is an error in the laboratory, if necessary, repeat the blood test. Or at the same time draw normal human blood control. If there is a change in the test results, you should think of the influence of the above factors, and conversely, you should think of the influence of anticoagulant when applying drugs and changing the type of diet. Consult your doctor promptly. Treatment of bleeding complications (1) Minor bleeding: e.g. bleeding gums, skin bruises, the dosage of warfarin can be reduced by 1/4-1/8 according to the results of laboratory tests. (2) Obvious bleeding: e.g. epistaxis, hematuria, the use of warfarin can be discontinued for 1 or 2 days. (3)Serious bleeding:such as hemoptysis, vomiting blood, intracranial hemorrhage, immediately static injection of vitamin K120mg, wait for the bleeding to stop and observe for 1-2 days, 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 operating hospital. Anticoagulation during menstruation Most people do not have much menstruation, and the amount of anticoagulants used remains unchanged; 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, such as menstrual disorders, bleeding persists, menstruation-regulating medications should be taken; very few cases of heavy bleeding, hysterectomy is required.