Contents:
- Medical Video: Hemostasis: Lesson 4 - Tests (INR, PTT, platelets, fibrinogen, D-dimer)
- What should I know before undergoing activated clotting time?
- What do the test results mean?
Medical Video: Hemostasis: Lesson 4 - Tests (INR, PTT, platelets, fibrinogen, D-dimer)
Definition
What is activated clotting time?
Activated clotting time (ACT) test is used to measure blood response to the use of several anticoagulants such as heparin or direct thrombin inhibitors (DTI). These drugs are commonly used in angioplasty, kidney dialysis, and cardiopulmonary bypass (CPB).
This test measures the time it takes for the blood to freeze after being given several stimulants. With ACT, your doctor can observe your blood reactions when you encounter anticoagulants such as heparin.
Both APPT (activated partial thromboplastin time) and ACT (activated clotting time) can be used to monitor patients given heparin during the CPB process (cardiopulmonary bypass). But compared to APTT, ACT has more advantages.
First, ACT results are more accurate than APTT when high-dose heparin is used to inhibit coagulation. This is very useful for some clinical situations that require high doses of heparin, including CPB. Unlike ACT, APTT is not able to measure conditions like this. The ACT target is 400-480 seconds in CPB (cardiopulmonary bypass).
Second, ACT does not require a lot of costs and is easier to do even this test can be done on the bed. Of course this can save time and energy.
When should I undergo activated clotting time?
This test is carried out for patients who will undergo:
- percutaneous coronary intervention
- kidney dialysis
- CPB (Cardiopulmonary bypass)
Prevention & warning
What should I know before undergoing activated clotting time?
Several factors that can affect test results include:
- biological conditions such as hypothermia, blood dilution, platelet count and function
- factors that affect heparin pharmacokinetics (for example, kidney disease or liver disease) and anti-heparin
- blood clots can increase ACT results more than normal so the test results are inaccurate
Pay attention to warnings and precautions before undergoing this operation. If you have questions, please consult a doctor for further information and instructions.
Process
What should I do before undergoing activated clotting time?
There is no special preparation before undergoing this test. However, your doctor may check your health condition first. Consult your doctor about certain preparations before undergoing the test.
You are recommended to use short-sleeved clothing to make it easier to take blood samples from your hands.
What is the activated clotting time process?
The medical personnel who are in charge of taking your blood will take the following steps:
- wrap an elastic belt around your upper arm to stop the blood flow. This makes the blood vessels under the bond enlarge making it easier to inject needles into the vessels
- clean the part to be injected with alcohol
- inject a needle into a vein. More than one needle may be needed.
- attach the tube to the syringe to fill it with blood
- remove the ties from your arms when taking blood is enough
- attach gauze or cotton to the injected part, after the injection is finished
- put pressure on the part and then put on a bandage
What should I do after I get activated clotting time?
Some people may feel pain when a syringe is inserted into the skin. But for most people, the pain will gradually disappear when the needle is right in the vein. Generally, the level of pain experienced depends on the expertise of the nurse, the condition of the arteries, and a person's sensitivity to pain.
After going through the process of taking blood, wrap your hands in a bandage. Press the vein slowly to stop bleeding. After doing the test, you can do activities as usual.
If you have questions about the test process, please consult a doctor for further instructions.
Explanation of Test Results
What do the test results mean?
The normal range for each test may vary depending on the laboratory you choose. Usually, the normal range will be written on the test paper. Discuss with our doctor or health professional before the test and after receiving the test results for accurate results.
Normal
Blood clots in 70-120 seconds.
If you are on anticoagulant therapy, the normal range is 150-600 seconds.
Abnormal
Blood takes longer to freeze. Some causes include:
- use of Heparin
- lack of blood clotting factors
- cirrhosis
- lupus inhibitor
- use of Warfarin
Blood requires a shorter time to freeze (aggregation) which can interfere with blood flow.
The normal range for activated clotting time tests can vary depending on the laboratory you choose. Discuss with your doctor if there are questions about your test results.
Hello Health Group does not provide medical advice, diagnosis or treatment.
