What is the normal value of prothrombin time? The normal value is 12- 14 seconds. Some patients will ask, what is the role of detecting prothrombin time? Prothrombin time is a very important index reflecting liver synthesis function, reserve function, severity of pathological changes and prognosis. Low prothrombin time can be seen in women's oral contraceptives, thromboembolic diseases and hypercoagulability.
However, other diseases cannot be excluded, such as hepatitis B, liver cirrhosis, fatty liver and low prothrombin time caused by alcoholic hepatitis.
Director Du finally reminded: Everyone must pay attention to the low prothrombin time when they are examined in the hospital. It is best to go to a hospital with good conditions for examination, understand the condition and make clear the cause, and treat them in time, so as not to delay the treatment time.
Prothrombin time detection
1.Purpose
1. 1 Preoperative detection.
The consultation of 1.2 DIC.
1.3 detection of anticoagulant therapy.
2. Test project analysis principle
Excessive tissue thromboplastin and calcium ions are added to the plasma to change prothrombin into thrombin, and the latter changes fibrinogen into fibrin. The time required to observe plasma coagulation is prothrombin time.
3. Specimen collection
3. 1 Take venous blood on an empty stomach in the morning.
3.2 1.8 ml venous blood+0.2 ml 109mmol/L sodium citrate, inverted for 5 ~ 8 times and fully mixed.
4. Specimen storage: plasma is separated within 1 hour (3000r/min× 10min), stored at room temperature for no more than 2 hours, and stored at 2 ~ 8℃ for no more than 4 hours. After separation, the plasma can be sealed below -20℃ for 24 hours.
5. Specimen rejection criteria: the anticoagulant does not meet the requirements, the amount of blood collected is inaccurate, and samples with coagulation, hemolysis, lipemia, no bar code and no label cannot be determined.
6. Instruments and reagents
Instrument: Sysmex CA-7000 automatic blood coagulation analyzer.
Reagent: Thromborel S from DADE BEHRING, USA, redissolved with 10 ml distilled water, and bathed in water at 37℃15 ~ 20min. 2 ~ 8℃ (screw down the bottle cap) can be stored for 5 days.
7. Operating steps
7. 1 input work list: enter the work list input interface from the main menu [Work List], select [ID,No. Enter], input the first specimen number, and select the test item "PT". Use "↑↓" to input other specimen numbers and test items in sequence, press [Enter] to confirm, press [QUIT] to exit the [ID,No. Enter] interface, and then press [Enter] to make the instrument accept the input tasks.
Quick batch input: after inputting a specimen number and test item, the cursor stays on the item, and press [Repeat] to repeat the input of the same test item of the whole specimen, with the number increasing in ascending order, and press [NEXT] to be the next sample rack.
Specimen number or test item modification: press [Enter Cancel] to modify, and then press [Enter] to confirm.
7.2 Place the centrifugally separated samples on the sample rack in sequence according to the above-mentioned work list, and then arrange the sample rack on the right side of the Sampler in sequence.
7.3 Confirm that the instrument is in the "Ready" state, press the [Start] key, start sample injection, and conduct sample determination.
7.4 Add sample rack: Follow the steps of 4.3. 1 and 4.3.2, and then press [Rigester] to continue to confirm the test task.
7.5 After testing, the results are only transmitted to the computer LIS system. (See the corresponding work instruction for specific operation)
8. Indoor quality control
8. 1 quality control: level1:ci-troll1
Level 2：Ci-Trol2
Level 3：Ci-Trol3
8.2 Configuration method: 1 ml distilled water is redissolved at room temperature 10 minutes or so.
8.3 Quality Control Procedure
8.3. 1 Set the target value, warning limit and out-of-control limit of each test item of the quality control product in the function bar [QC].
8.3.2 Add the configured quality control product Level 1 into a clean plastic sample cup and put it on the specimen rack.
8.3.3 Select [Work List] from the main course, select [ID,No. Enter], enter [QC 1] in the numbered position, select the test item, confirm with [Enter], press [QUIT] to exit the [ID,No. Enter] menu, and then press [Enter] to accept the input.
8.3.4 Press the [Start] key to start testing. After testing, the results are automatically input into the quality control chart in the [QC] column of the function bar.
8.3.5 Carry out quality control analysis of quality control products Level 2 and Level 3 according to the same operation steps.
8.3.6 The quality control results are qualified before testing the patient's specimens. For details of quality control rules, please refer to the indoor quality control work instruction.
9. Biological reference interval
Pt:11.0 ~14.0 seconds INR value: 0.8 ~1.2.
10. Critical value
Pt ≥18second
11.reportable range of patient results
Pt: 7 ~100 second
12. Clinical significance
12. 1 PT prolongation is seen in congenital deficiency of coagulation factors Ⅱ, ⅴ, ⅶ and ⅹ. Low (no) fibrinogen; Acquired in DIC, primary fibrinolysis, vitamin K deficiency, liver disease, and anticoagulant substances (such as oral anticoagulants and heparin) in the blood circulation.
Shortening of 12.2 PT: seen after congenital coagulation factor V increase, oral contraceptives, hypercoagulable state (early DIC, acute myocardial infarction, etc.), thrombotic diseases (cerebral thrombosis, acute thrombophlebitis), multiple myeloma, digitalis poisoning and ether anesthesia.
12.3 Important indicators for monitoring oral anticoagulants (such as warfarin and dicoumarin).
13. Precautions
13. 1 Improper sample collection and processing, such as blood and anticoagulant not fully mixed, and blood clots appear, and excessive force is exerted when mixed, which makes the sample hemolytic and causes the result variation.
13.2 influence of fibrinolytic drugs, such as dicoumarin, streptokinase, urease, etc.
The increase of 13.3 FDP prolongs the solidification time.
13.4 Some drugs, such as oral contraceptives, estrogen, asparaginase and naloxone, affect the test results.
Determination of activated partial thromboplastin time in plasma
1. Purpose
1. 1 Preoperative detection.
The consultation of 1.2 DIC.
1.3 detection of anticoagulant therapy.
2. Test project analysis principle
Various activators (such as clay) are used to activate the coagulation factor Ⅶ in the plasma to be tested, and then phospholipids are used as the active surface of coagulation to activate the endogenous coagulation pathway, so that prothrombin can be converted into thrombin, and thrombin can convert fibrinogen into fibrin, which leads to the coagulation of plasma. It is observed that the time required from adding reagents to plasma coagulation is the activated partial thromboplastin time APTT.
3. Specimen collection
3. 1 Take venous blood on an empty stomach in the morning.
3.2 1.8 ml venous blood+0.2 ml 109mmol/L sodium citrate, inverted for 5 ~ 8 times and fully mixed.
4. Specimen storage: plasma is separated within 1 hour (3000r/min× 10min), stored at room temperature for no more than 2 hours, and stored at 2 ~ 8℃ for no more than 4 hours. After separation, the plasma can be sealed below -20℃ for 24 hours.
5. Specimen rejection criteria: the anticoagulant does not meet the requirements, the amount of blood collected is inaccurate, and samples with coagulation, hemolysis, lipemia, no bar code and no label cannot be determined.
6. Instruments and reagents
Instrument: Sysmex CA-7000 automatic blood coagulation analyzer.
Reagent: Actin Reagente: It is a liquid reagent that does not need to be redissolved. After opening the bottle, it is directly put into the corresponding reagent position for use. It can be stored for 5 days at 2 ~ 8℃ (screw down the bottle cap and seal the vial).
0.025m calcium chloride (CaCl _ 2) can be stored for 5 days at 2 ~ 8℃.
7. Operating steps
7. 1 input work list: enter the work list input interface from the main menu [Work List], select [ID,No. Enter], input the first specimen number, and select the test item "APTT". Use "↑↓" to input other specimen numbers and test items in sequence, press [Enter] to confirm, press [QUIT] to exit the [ID,No. Enter] interface, and then press [Enter] to make the instrument accept the input tasks.
Quick batch input: after inputting a specimen number and test item, the cursor stays on the item, and press [Repeat] to repeat the input of the same test item of the whole specimen, with the number increasing in ascending order, and press [NEXT] to be the next sample rack.
Specimen number or test item modification: press [Enter Cancel] to modify, and then press [Enter] to confirm.
7.2 Place the centrifugally separated samples on the sample rack in sequence according to the above-mentioned work list, and then arrange the sample rack on the right side of the Sampler in sequence.
7.3 Confirm that the instrument is in the "Ready" state, press the [Start] key, start sample injection, and conduct sample determination.
7.4 Add sample rack: Follow the steps of 4.3. 1 and 4.3.2, and then press [Rigester] to continue to confirm the test task.
7.5 After testing, the results are only transmitted to the computer LIS system. (See the corresponding work instruction for specific operation)
8. Indoor quality control
8. 1 quality control: level1:ci-troll1
Level 2：Ci-Trol2
Level 3：Ci-Trol3
8.2 Configuration method: 1 ml distilled water is redissolved at room temperature 10 minutes or so.
8.3 Quality Control Procedure
8.3. 1 Set the target value, warning limit and out-of-control limit of each test item of the quality control product in the function bar [QC].
8.3.2 Add the configured quality control product Level 1 into a clean plastic sample cup and put it on the specimen rack.
8.3.3 Select [Work List] from the main course, select [ID,No. Enter], enter [QC 1] in the numbered position, select the test item, confirm with [Enter], press [QUIT] to exit the [ID,No. Enter] menu, and then press [Enter] to accept the input.
8.3.5 Press the [Start] key to start testing. After testing, the results are automatically input into the quality control chart in the [QC] column of the function bar.
8.3.6 Conduct quality control analysis of quality control products Level 2 and Level 3 according to the same operation steps.
8.3.7 The quality control results are qualified before testing the patient specimens. For details of quality control rules, please refer to the indoor quality control work instruction.
9. Biological reference interval
Aptt: 20.0 ~ 40.0 seconds (the patient's result is abnormal if it exceeds the normal control 10 seconds or more).
10. Critical value
APPT ≥50 seconds
11.reportable range of patient results
Aptt:15.0 ~156.0 seconds
12. Clinical significance
12. 1 APTT is often used to screen endogenous coagulation systems (ⅷ, ⅸ, ?, factors) and monitor heparin anticoagulation therapy.
12.2 APTT prolongation: seen congenital coagulation factor deficiency (such as hemophilia A and B, contact factor, Ⅶ deficiency, VWF, etc.); Deficiency of multiple coagulation factors (such as severe liver disease, vitamin K deficiency, DIC, hyperfibrinolysis, etc.); There are anticoagulants in the blood.
12.3 APTT shortening: it is found in hypercoagulable state such as DIC and pregnancy-induced hypertension syndrome.
12.4 is the first choice for monitoring heparin therapy.
13. Precautions
13. 1 Improper sample collection and processing, such as blood and anticoagulant not fully mixed, and blood clots appear, and excessive force is exerted when mixed, which makes the sample hemolytic and causes the result variation.
13.2 influence of fibrinolytic drugs, such as dicoumarin, streptokinase, urease, etc.
The increase of 13.3 FDP prolongs the solidification time.
13.4 Some drugs, such as oral contraceptives, estrogen, asparaginase and naloxone, affect the test results.