What is the value of 0 99

From Lena Machetanz, doctor
and, medical editor and biologist
All NetDoktor content is checked by medical journalists.

The INR value tells how quickly the blood coagulates. It refers to a standard of the World Health Organization (WHO) and replaces the Quick value, which was often determined in the past, due to better comparability. Read more about the topic here: What is the INR value exactly? When is it determined? When is the INR normal? How can it deviate upwards or downwards?

What is the INR value?

The INR value (abbreviation for "International Normalized Ratio") is a laboratory test for blood clotting. It records the blood coagulation factors V, VII, X and II. To determine the INR value, the coagulation time of a patient's blood plasma is divided by the coagulation time of a standardized normal plasma.

In the past, the so-called Quick value (also known as the "thromboplastin time") was often measured instead of the INR value. However, it has the disadvantage that its result is heavily dependent on the batch and method. That is why the Quick value is now usually converted into the standardized (and therefore more comparable) INR value. The following applies: Quick and INR behave the other way around. So if the Quick value is high, the INR value is low and vice versa.

When is the INR value determined?

The doctor determines the INR value in the following cases:

  • if a deficiency in vitamin K is suspected
  • to control therapy with vitamin K antagonists (phenprocoumon, warfarin), which are intended to prevent blood clots (such as pulmonary embolism)
  • to assess the liver function in severe liver diseases (for example liver damage from fungal toxins)
  • to rule out a bleeding disorder before a planned operation
  • if a tendency to bleeding is suspected, for example due to prolonged and particularly heavy menstrual bleeding or bleeding into joints

INR / Quick value table

In healthy adults this is the case INR value at 0.85 to 1.15. A higher target range is aimed for in patients treated with anticoagulants (e.g. for deep vein thrombosis: 2.0 to 3.0).

For the Quick value The following standard ranges apply:

When is the INR too low (or the Quick value too high)?

If the INR value is reduced, the Quick value is correspondingly too high. Reasons for this are, for example, the use of certain antibiotics (cephalosporins or penicillins). Antispasmodic drugs (anticonvulsants) can also lower the INR value or increase the Quick value. However, a lowered INR value is not an indication of illness and generally does not require any further clarification.

When is the INR too high (or the Quick value too low)?

An increased INR value (and, by analogy, a decreased Quick value) indicate that blood clotting does not work as well as in a healthy person. This can have the following causes, for example:

  • Deficiency of certain coagulation factors (for example fibrinogen)
  • Taking oral anti-coagulants (anticoagulants)
  • Vitamin K deficiency, for example in severe liver disease or celiac disease
  • Taking certain medications (barbiturates, acetylsalicylic acid, heparin, coumarin, and others)

In addition, incorrect blood collection or incorrect handling of the blood sample can lead to incorrectly increased INR values. This happens, for example, if the tourniquet was placed on the patient's upper arm for too long before blood was drawn or if the blood collection tube was not sufficiently filled with blood.

What to do if the INR value changes?

If there is a deviation from the INR normal value, it is important to find out the cause. If the values ​​are elevated before a planned operation, the doctor must first rule out the possibility that the patient has impaired blood clotting. If necessary, the operation must also be postponed until this diagnosis has been completed. If there is a diet-related vitamin K deficiency, this can be remedied with substitution therapy. This means that the patient receives vitamin K supplements until the deficiency is compensated for and blood clotting has normalized.

A deviation from the INR normal value is even desirable in patients who are treated with anticoagulants for a specific underlying disease. For example, an INR value between 2.0 and 3.0 is aimed for in patients with atrial fibrillation and a value for patients with a mechanical heart valve INR value from 2.0 to 3.5.

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