When we get a wound somewhere in our body and start bleeding, our body works very hard to stop the bleeding, right? This stopping of bleeding is what we call blood clotting. Sometimes this blood clotting may not happen properly. It may be too slow, or it may happen too fast. In such cases, an important test to know exactly how your blood clotting process is going is called the Prothrombin Time (PT/INR) Test . Let's talk about this in detail today.
What is the Prothrombin Time (PT/INR) Test?
Simply put, the Prothrombin Time (PT) , or sometimes called PT/INR, measures how quickly your blood clots. The results can be given in seconds, or, more commonly, in a calculation called the International Normalized Ratio (INR) .
When you have an injury and are bleeding, our blood contains special proteins called clotting factors . These are like a team that works together. This team works together to form a clot and stop the bleeding. Prothrombin is another essential protein that is essential for this process. It is produced by our liver.
Doctors usually do another test called the Partial Thromboplastin Test (PTT) along with the PT test. The PTT test looks at how the other clotting factors in your blood are working. By combining the information from both, your doctor can get a better understanding of your condition.
Why do we do this PT Test? What do we expect from it?
Doctors do this PT test to check if your blood is clotting properly. Imagine, if your blood is clotting very poorly, even a small injury can cause a large amount of blood to flow through your body. Also, if your blood is clotting too quickly, those blood clots can form and block our blood vessels. This is also a dangerous situation.
There are several reasons why your doctor may decide to perform this PT test:
1. Check if the Warfarin medication is working properly.
Warfarin , which some people may know by the brand name Coumadin® , is a blood thinner. It is given to prevent the formation of dangerous blood clots. If not treated properly, people who are at risk for blood clots can develop serious conditions such as Deep Vein Thrombosis (DVT) or Pulmonary Embolism (PE) in their veins. So, doctors often do this PT test to make sure that the dosage of warfarin you are being given is correct.
2. Prepare before surgery
If you are having surgery, your doctor may order this test to check your blood clotting ability before the procedure. This is to make sure you are not at risk of excessive bleeding during the procedure.
3. Identify bleeding and blood clotting disorders
A PT test can help determine if you have a medical condition that causes you to bleed excessively. Some people have it, such as bruising easily, frequent nosebleeds, or bleeding that doesn't stop even from a small cut. This test can help determine the cause of these symptoms.
4. Check for liver disease
As I mentioned earlier, a protein called prothrombin is made by the liver. So, a problem with prothrombin is a sign that you may have liver disease. The PT test is one of the liver function tests that is done to see how well the liver is working and how much liver disease there is.
How is this Prothrombin Time Test done?
This is a very simple blood test. After a small amount of blood is drawn from you, the lab adds a substance called thromboplastin to the blood sample. This helps the blood to clot. Then, a specialist in the lab uses a device to measure how long it takes for your blood sample to clot.
How to prepare for the PT Test?
Your doctor will explain how to prepare for this. You may need to do the following:
- Avoid taking certain medications: For example, some medications, such as antibiotics , can increase your PT/INR. Also, things like oral birth control pills and hormone replacement therapy can decrease your PT.
- Reduce Vitamin K: You may be told to stop taking Vitamin K supplements or reduce your intake of foods rich in Vitamin K, such as kale, spinach, broccoli, and tea leaves. This is because Vitamin K is a substance that affects blood clotting.
But remember, all of this should only be done under your doctor's advice. Never stop taking your medication without your doctor's advice.
What to expect when taking the PT Test?
This is just like donating blood. A doctor or nurse will do it like this:
- The area where your blood will be drawn will be cleaned with alcohol. Then, an elastic band will be placed over your arm.
- They tell you to shake your hand to get the blood vessels to come up better.
- Then, a needle is slowly inserted into the vein and a small amount of blood is collected into a small vial. You may feel a slight stinging sensation when the needle is inserted.
- After the blood is drawn, a small plaster or bandage is applied to the site where the needle was inserted.
Sometimes, this test is done by taking a small amount of blood from your fingertip. There are also at-home PT test kits that work by taking blood from your fingertip. If you are taking warfarin and need to take this test frequently, your doctor may recommend that you use a home kit like this. If so, you will be instructed on how to use it and how to report the results to your doctor.
What happens after the PT Test?
Usually, after the PT test, you can go about your daily activities as usual. You may experience some discomfort or bruising where the needle was inserted. But this does not last long.
What are the results we get? What does it mean?
The lab reports the results of the PT test in seconds, or (more commonly) as a value called the International Normalized Ratio (INR) . This INR value is a standard measurement introduced by the World Health Organization (WHO). This INR method was introduced to ensure that the results do not differ due to slight differences in the testing methods of different labs, and that everyone can give the same interpretation.
Here are the normal ranges for PT/INR results:
- If in seconds: 11 to 13.5 seconds.
- INR value: 0.8 to 1.1. (This is for someone who is not taking blood thinners like warfarin)
- If you are taking warfarin, your INR should be between 2.0 and 3.0 . (However, in some medical conditions, a higher or lower INR may be desired. This will be determined by your doctor.)
Abnormal PT results
A high PT test result or INR means that your blood is taking longer than normal to clot. If you are not taking warfarin, this could be a sign that you have a bleeding disorder, a clotting disorder, or a liver problem. It could also mean that you do not have enough vitamin K in your body.
If you are taking warfarin, your INR value may be abnormal (either too high or too low) for the following reasons:
- If you are not taking the correct dose of warfarin.
- Some over-the-counter medicines you take without a doctor's advice, for example cold medicine and vitamin supplements, may interact with warfarin.
- Some foods and drinks you consume, such as kale, spinach, cranberry juice, and alcohol, may interact with warfarin.
- If a medication you are taking for another condition affects the effectiveness of warfarin and increases or decreases your INR.
How long does it take to know the test results?
Most people can get their PT/INR test results within a few hours or a day. Fingerstick tests can give results in minutes. However, if your blood sample needs to be sent to another lab, it can take several days for the results to come back.
If the results are abnormal, what do you do next?
Doctors usually use both the PT test and the PTT test results to decide what to do next. Depending on your condition, your doctor may order more tests. This is done to accurately diagnose the disease and start the right treatment for it. The PT test is one of the first tests to diagnose a bleeding or clotting disorder. To confirm the diagnosis, more tests are needed.
If you are taking warfarin, your doctor will adjust your dose to keep your blood clotting properly, without the risk of blood clots.
When should I call my doctor?
If you have any questions about how to prepare for this PT test, how to get the results, or what to do next, be sure to ask your doctor. Because everyone's situation is different, only your doctor can give you the best guidance on what your results mean for your health plan.
Remember, when you have a cut and are bleeding, your body quickly forms a clot to stop the bleeding and start healing. If that doesn't happen, doctors use this Prothrombin Time (PT) test to find out why.
In summary, things to remember
Okay, so here are some of the key points you need to remember from what we've talked about today:
- The Prothrombin Time (PT/INR) test measures how quickly your blood clots.
- If you are taking blood thinners like Warfarin , you will need to have this test done more often.
- This helps diagnose bleeding disorders, blood clotting disorders, and some liver diseases.
- You may need to do some preparation before the test, which the doctor will tell you about.
- If the results are abnormal, the doctor will find the cause and prescribe the necessary treatment.
So, if your doctor asks you to do this PT/INR test, don't be afraid of it. It's a simple test that will tell you important information about your health. Your doctor will explain everything to you about what your results mean and what to do next.
` Prothrombin time test, PT/INR test, blood clotting, warfarin, blood tests, liver function, bleeding
💬 අදහස් (0)
තවමත් කිසිදු අදහසක් පළ කර නොමැත. ඔබේ අදහස පළමු වරට මෙහි එක් කරන්න.
ඔබේ අදහස එක් කරන්න