Objective: To explore the effect of high-fat chyle on coagulation function measurement results. Methods: Collect two portions of high-fat chyloblood, one using normal temperature high-speed centrifugation to separate the plasma (fat-free chylo-plasma), and one using conventional low-speed centrifugation to separate the plasma (original plasma), and then use the Sysmex CA7000 blood coagulation analyzer to measure the fat-free chylo. Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen (FIB) measurements of plasma and raw plasma. At the same time, the PT, APTT, TT and FIB of the original plasma were measured manually, and the measurement results were compared. Results: The difference between the PT and FIB results of the original plasma measured by the Sysmex CA7000 blood coagulation analyzer and the results of the fat-free chylo-plasma measured by the Sysmex CA7000 blood coagulation analyzer and the manual method of measuring the original plasma were statistically significant (P<0.01), APTT There was no statistically significant difference between PT, APTT, FIB and TT (P>0.05); compared with the results measured by the Sysmex CA7000 blood coagulation analyzer and the manual method, there was no statistically significant difference in the four indicators of PT, APTT, FIB and TT (P >0.05). Conclusion: High-fat chyle has a serious impact on the results of blood coagulation analyzer measurement of PT and FIB. Using normal temperature and high-speed centrifugation to separate plasma can remove the impact of high-fat chyle on the measurement results.
Keywords: Chylous blood; prothrombin time; partially activated thrombin time; thrombin time; fibrinogen; blood coagulation analyzer
Coagulation function is a routine test in clinical laboratories Items generally include the measurement of coagulation factors such as prothrombin time, activated partial thromboplastin time, fibrinogen and thrombin time. It is used for pre-operative examination, thrombosis treatment and monitoring of anticoagulant use in DIC treatment, etc. It is one of the emergency inspection items [1]. The classic method for measuring coagulation factors is the manual method, but due to the complex operation and low efficiency, it cannot meet the needs of clinical determination of large batches of specimens. With the development of laboratory testing technology, clinical laboratories currently use automatic blood coagulation analyzers to measure coagulation function in batches. The measurement results of the blood coagulation analyzer are susceptible to interference from high-fat chyloblood. High-fat chyloblood samples need to be measured manually, which brings inconvenience to the work. This article discusses the influence of high-fat chyle on the measurement results of blood coagulation analyzer and the method of removing the interference of fat chyle. The report is as follows.
1 Materials and Methods
1.1 Specimens
Forty-five cases of chylo-plasma were obtained from outpatients and inpatients in our hospital from June 2006 to December 2006. A special vacuum anticoagulation tube for coagulation function (containing 0.2 ml of 109 mmol/L sodium citrate) was used to collect 1.8 ml of venous blood, and the measurement was completed within 4 hours.
1.2 Instruments
SYSMEX CA-7000 blood coagulation analyzer, product of Japanese SYSMEX; TGL-16C desktop ordinary high-speed centrifuge.
1.3 Reagents
Using the original supporting reagents and quality control materials of SYSMEX CA?7000 blood coagulation analyzer.
1.4 Method
1.4.1 Preparation of fat-free chyloblood plasma
Collect obviously high-fat chyloblood coagulation function test specimens and centrifuge at 3 000 r/min After 10 minutes, the original plasma was obtained. Divide the specimen into two parts, and centrifuge one part at 13,000 r/min for 10 min. The clear plasma in the lower layer is the fat-free chylolytic plasma. The instrumental measurement method used SYSMEX CA-7000 blood coagulation analyzer to measure PT, APTT, FIB and TT of fat-free chylo plasma and original plasma. Determine PT, APTT, FIB, and TT in the original plasma by manual method, repeat the measurement 2 to 3 times, and take the average value.
1.4.2 Data processing method
All experimental data are expressed in ±s and analyzed using paired t test.
2 Results
The results of measuring the original plasma using the instrument method, the results of the fat-free chylo-plasma and the results of measuring the original plasma using the manual method are shown in Table 1.
Table 1 Determination results of PT, APTT, FIB and TT in fat-free chylo-plasma and original plasma (omitted) Note: # symbol indicates that no specific results can be measured, and the result is expressed as 0; * indicates the manual method and fat-free chylo-plasma instrumental method Comparison, P<0.01.
As can be seen from Table 1, the difference between the PT and FIB measurement results of the original plasma measured by the instrumental method and the results of fat-free chylo-plasma measured by the instrumental method and the manual method of measuring the original plasma is statistically significant (P <0.01), the difference between APTT and TT is not statistically significant (P>0.05); compared with the results measured by the instrument method and the manual method, there is no statistically significant difference in the four indicators of PT, APTT, FIB, and TT. (P>0.05).
3 Discussion
Coagulation factors PT, APTT, FIB and TT are routine measurement items for clinical judgment of coagulation function, and are required items for screening for abnormal coagulation function before surgery. Diagnostic items such as examination of prothrombotic states, experimental diagnosis of disseminated intravascular coagulation and bleeding disorders (DIC), and medication guidance and prognosis estimation for patients receiving various anticoagulation treatments are of great value in the diagnosis and treatment of clinical diseases. The classic method for measuring coagulation factors is manual measurement, and measurement standardization plans have been formulated by authoritative international academic organizations such as the International Committee for Standardization in Hematology (ICSH), the International Committee on Thrombosis and Hemostasis (ICTH), and the National Committee for Clinical Laboratory Standards (NCCLS). However, due to the complex operating procedures and low efficiency of the manual method, it cannot be adapted to the detection of large quantities of specimens in large hospitals. Therefore, the use of automatic blood coagulation analyzers to measure coagulation factors is a key means to solve the problem of large-volume specimen determination, and is widely used in hospitals at all levels.
At present, automatic blood coagulation analyzers can be divided into two types according to the measurement principle: mechanical vibration method and photoelectric turbidimetry. The measurement principle of photoelectric turbidimetry is that when a beam of light (light source halogen lamp) passes through the sample cup, transmission and scattering will occur. During the coagulation process of the plasma in the sample cup, fibrinogen gradually transforms into fibrin, and its physical properties change. , causing the intensity of transmitted light and scattered light to change, thereby determining the end point of coagulation [2]. The Sysmex CA7000 blood coagulation analyzer is one such instrument. It is widely used in clinical laboratories due to its low measurement cost and high measurement accuracy and precision for normal appearance specimens. It can be seen from our measurement results that high-fat chyle has a significant impact on the measurement results of PT and FIB measured by the Sysmex CA7000 blood coagulation analyzer, which can cause the FIB measurement results to be undetectable and the PT measurement results to be high. This is because fatty chyle makes the plasma turbidity too high, which exceeds the detection range of the instrument, causing the instrument to be unable to detect results or the test data to be inaccurate. It has been reported that the method of artificially adding interfering agents was used to evaluate the ability of the Sysmex CA7000 blood coagulation analyzer to resist high-fat chyloblood, indicating that high-fat chyloblood has no effect on the test results [3]. Our measurement results also show that high-fat chyle blood has little effect on the measurement results of APTT and TT, which is consistent with reports, but it has a significant impact on the measurement results of PT and FIB. The difference was statistically significant (P﹤0.01) when compared with the results measured by manual method and the results determined by fat-removed chylo-plasma. This may be due to the increase in turbidity caused by the artificial addition of interfering agents, which is different from the properties of fat chyle in the body. Methods reported in the literature to remove high-fat chyle include specimen placement [2], low-temperature high-speed centrifugation [4, 5], etc. The specimen placement method takes a long time, cannot detect in time, and delays diagnosis and treatment; the low-temperature high-speed centrifugation method has higher equipment requirements and is difficult to equip in general laboratories. We used a high-speed centrifuge at room temperature to remove fat chyle. The results of PT, APTT, TT and FIB in the plasma were consistent with the manual method, indicating that high-speed centrifugation (13 000 r/min for 10 min) at room temperature to remove fat chyle had an impact on coagulation factors in the plasma. Activity has no effect. Room-temperature high-speed centrifuges are cheap and easy to equip in laboratories. Therefore, high-speed centrifugation at room temperature is a simple and easy method to eliminate the influence of high-fat chyle on the measurement results of blood coagulation analyzer.
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