aPTT from citrate plasma. Blood sampling only on location Mönchengladbach. This test has to be performed directly at the lab, cannot be sent.
To investigate blood coagulation problems (citrate tube). In addition, the test is used to monitor the effect of blood thinners (e.g. heparin).
The activated partial thromboplastin time(aPTT) is used to determine how long it takes for the blood to clot. Blood coagulation is a very complex process consisting of a series of successive chemical reactions between different coagulation factors, which are produced in the liver. The time it takes for a clot to form in the blood sample is called activated partial thromboplastin time and is measured in seconds.
The test is used to examine blood clotting. Clotting too fast leads to an increased risk of thrombosis and clotting too slow can lead to serious bleeding.
The physician will request anaPTT test, sometimes along with other coagulation tests such as thePT, for patients who suffer from bleeding tendencies, clotting tendencies, or severe liver disease.
Sometimes the test is requested for women who have repeated miscarriages; it could be that too many anticoagulants in the blood cause a miscarriage.
In some cases, the doctor requests the test prior to surgery if the patient's history indicates an increased risk of bleeding.
The doctor also requests anaPTT when a patient is administered heparin (blood thinner) to prevent clotting in the body. The administration must remain within narrow limits. Too high a dose of heparin can cause serious bleeding; too low a dose increases the risk of blood clots.
A shortenedaPTT clotting time, i.e. less than 30 seconds, can indicate an increased amount of coagulation factor typeVIII in the blood. This coagulation factor is often temporarily increased after an acute inflammation or injury.
An extendedaPTT clotting time, i.e. longer than 40 seconds, means that the formation of a clot takes longer than expected. Usually, something is going on with the clotting factors, substances the body makes in the liver that are needed to make the blood clot. A prolongedaPTT can be caused by:
- a shortage of coagulation factors, for example due to a hereditary defect (e.g. Von Willebrand disease);
- inhibitors of coagulation factors. Sometimes it is a specific inhibitor of a coagulation factor that is used to treat patients with a bleeding tendency. For example, people with haemophilia A (bleeding tendency) are administered coagulation factorVIII, but the drug does not work in patients who have a specific inhibitor of coagulation factorVIII in their blood;
- treatment with heparin as a blood thinner;
- Treatment with coumarin as a blood thinner may also prolong theaPTT test, but this treatment is not controlled by this test;