Hey everyone. With only a few weeks down to the end of SIP, I bet everyone's been working hard on their MP. Anyway, for my turn in blogging, I'll touch on what I've learnt in the Coagulation section of the lab, which deals with blood samples that have been placed in 3.2% sodium citrate tubes. (shown above)
In this entry I'll highlight a particular test that is the most highly requested test for my section.
And that would be the test for Prothrombin Time (PT).
Prothrombin time is a test used to evaluate the extrinsic coagulation of the system. It can screen for congenital deficiencies of factors II, V, VII and X. PT can also monitor anticoagulant therapy (eg. warfarin medication), which is usually given on a long-term basis to patients who suffer from recurrent inappropriate blood clotting. The measurement of PT can aid in the control of the dosage of the drugs. PT is normally measured in seconds and the INR (Intl Normalized Ratio)
INR = (patient's results / normal patient average)
The ref range for patients on warfarin should be between 2.0-3.0. Those with high risk of clotting have a ref range of 2.5-3.5.
PT is usually evaluated with the results of Activated Partial Thromboplastin Time (aPTT) to assess the coagulation system better.
It irradiates red light at 660nm onto a mixture of blood plasma with added reagent (Dade Innovin) and it will read a change in turbidity as the fibrin clots are formed. This measures the coagulation time.
It also uses the Coagulation Point Detection Method (Percentage Detection Method) to calculate the coagulation time. This is considered as the time taken to achieve the amount of scattered light that is set for the coagulation detection point, susing the amount of scattered light that is present just after the start of detection as 0% and the amount of light scattered that is present at the completion of coagulation as 100%.
Antibiotics, aspirin, and cimetidine can increase the PT/INR. Barbiturates, oral contraceptives and hormone-replacement therapy (HRT), and vitamin K - either in a multivitamin or liquid nutrition supplement - can decrease PT. Certain foods (such as beef, green tea, broccoli, chickpeas, kale, turnip greens, and soybean products) contain large amounts of vitamin K and can alter PT results.
In this entry I'll highlight a particular test that is the most highly requested test for my section.
And that would be the test for Prothrombin Time (PT).
Prothrombin time is a test used to evaluate the extrinsic coagulation of the system. It can screen for congenital deficiencies of factors II, V, VII and X. PT can also monitor anticoagulant therapy (eg. warfarin medication), which is usually given on a long-term basis to patients who suffer from recurrent inappropriate blood clotting. The measurement of PT can aid in the control of the dosage of the drugs. PT is normally measured in seconds and the INR (Intl Normalized Ratio)
INR = (patient's results / normal patient average)
The ref range for patients on warfarin should be between 2.0-3.0. Those with high risk of clotting have a ref range of 2.5-3.5.
PT is usually evaluated with the results of Activated Partial Thromboplastin Time (aPTT) to assess the coagulation system better.
To run the test, my lab uses the Sysmex Ca-1500. We first check the tubes for clot then spin the sodium citrate tubes at 6000rpm for 3minutes. We then load the samples into racks and place them on the machine.The caps need not be removed as the machine has a probe that can pierce through the cap.
It works by using the Coagulation Reaction Detection Method (Scattered Light Detection Method)
It irradiates red light at 660nm onto a mixture of blood plasma with added reagent (Dade Innovin) and it will read a change in turbidity as the fibrin clots are formed. This measures the coagulation time.
It also uses the Coagulation Point Detection Method (Percentage Detection Method) to calculate the coagulation time. This is considered as the time taken to achieve the amount of scattered light that is set for the coagulation detection point, susing the amount of scattered light that is present just after the start of detection as 0% and the amount of light scattered that is present at the completion of coagulation as 100%.
Antibiotics, aspirin, and cimetidine can increase the PT/INR. Barbiturates, oral contraceptives and hormone-replacement therapy (HRT), and vitamin K - either in a multivitamin or liquid nutrition supplement - can decrease PT. Certain foods (such as beef, green tea, broccoli, chickpeas, kale, turnip greens, and soybean products) contain large amounts of vitamin K and can alter PT results.
1 comment:
hihi, can i ask why sodium citrate tubes must be used?why we cant used EDTA or sodium heparin tubes?thanks
Rachael
Tg01
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