High prothrombin time and INR results explanation

The results of Protime, INR test including such variations: Normal values, High PT with high PTT, high PT only, abnormal PT with other tests as PTT, CT, BT, and PLT

In case of Pregnancy PT with aPTT tests requested by gynecologist and the results may show an elevation in Protime only, usually aPTT is within normal.
In case of Bleeding and clotting disorders as in cardiovascular diseases and valves replacing patients the PT and aPTT are needed with other coagulation function tests, usually it should be normal of ordinary patients and raise gradually as the case be worse.
In case of Surgery PT,aPTT tests is requested.

PT test is the inverse relationship between the bleeding time and the hematocrit is particularly Prothrombin Time and Activated Partial Thromboplastin Time.
PTT (aPTT): (activated) partial thromboplastin time, tells you if patient on heparin is at a therapeutic level.
INR is made to unify PT time results between different Laboratories by internationalized normal ranges (INR) and calculated as the ratio of a patient’s prothrombin time to a normal (control) sample, raised to the power of the ISI value for the control sample used.
Thrombocytopenia is a Relationship between platelet count and bleeding time and means low thrombocytes count (Platelets).

PT INR reults explained
An example of PT test results is:
Prothrombin Time:
Control – 12 seconds
Patient – 18 seconds
Percent Activity – 34%
International Sensitivity index – 1.1
International normalize ratio – 1.6
Prothrombin ratio – 1.5
Activated Partial Thromboplastin time:
Patient – 47 seconds
Control – 30 seconds

Long prothrombin time and high INR can indicate:
a lack of one or more blood clotting factors (factors I, II, V, VII, or X), or the depression of vitamin K dependent Factors VII,X and II.
a lack of clotting factor activity,
a vitamin K deficiency,
liver disease,
A long PT time can be caused by treatment with certain medications, such as heparin or warfarin (Coumadin), that are used to liquefy the blood and decrease clotting.
Malabsorption or lack of intestinal colonization by bacteria (such as in newborns)

Blood thinners as NSAID or Anticoagulants as heparin and Coumadin dosage given for people being treated to prevent the formation of blood clots such patients with heart diseases of artery who suffer from blood clotting criteria and patients with severe liver inflammation, or patients after surgery heparin may be given to decrease clotting.

Anticoagulant dose must be adjusted gradually to avoid cute bleeding and according to the normal INR value and needed bleeding/clotting times as following:

The normal blood protime and INR is: PT between 10–13 seconds is normal this corresponding to International normalized ratio (INR) between 1.0–1.4 as International normal range of INR
For The warfarin (Coumadin) patients prothrombin time should be adjusted to be about 1.5 to 2.5 times the normal value (or INR values 2 to 3).
For People with artificial heart valves
Sometimes INR value should be higher than 3.0

Coumadin/warfarin dose that rise INR values between 1.5- 2.5 usually up to 3.0 mg then it adjusted for every case later.
Coumadin/warfarin dose needed to rise INR values higher than 3.0 usually starts from 5.0 mg and maybe go higher as needed for high bleeding demand as in heart valves surgeries.

The best solution to lower INR and PT time is vitamin K intake physiologically by nutrients rich in Vit.K or using Vitamin K therapy.

Example of medical condition may be as following:
I developed a DVT in the right shoulder (same arm as IV during surgery) , go to the lab once / week. Last week my INR was 2.9 and I have been taken 5mg of warfarin. This week my INR was 6.6.

The best time intervals to check for blood prothrombin time (Protime or INR) is 3 – 6 days according to half life time of Coumadin/warfarin in the blood (the time needed to fully metabolized usually it needs 2-4 days) with starting dose of 2.0 mg, cardiologist will request a lot of trial and error doses to fully understand and define the exact needed dose to make stabilization to patients, because some people metabolize Coumadin faster than others, after deciding the best dose and compatible time intervals patients can test for PT, and INR 1x/week, 2x/week, until reaching high stabilization it may be tested every 4 weeks.

Make a dosage adjustment it should not be until the previous dose make change then you can increase/decrease the doses and after INR screening.

Physician, Cardiologist, hematologist, Lab specialist, and cardiac liaisons nurses are the associated specialists to tell you the instructions and help you understand how Coumadin / Warfarin works to take the right doses and time intervals to carry out INR test.
Best Home PT testing solution is the use of Home Testers or machines as test strips and home testing machines/meters like Coaguchek and Coaguchek-type machines to cover the high costs of repeated INR tests.

The tests needed to diagnose bleeding and clotting status of the blood is The coagulation profile tests include a platelet count, a bleeding time, a coagulation time, a partial thromboplastin time, and a prothrombin time.
Initial laboratory tests of coagulation disorder are Complete blood count (CBC), platelet count, peripheral smear, prothrombin time (PT), activated partial thromboplastin time (APTT), and possibly a bleeding time. If the lesions appear vasculitic, consider a sedimentation rate and C-reactive protein determination. Serum creatinine and urinalysis can be ordered to screen for renal involvement. In vasculitis, the laboratory findings are often nonspecific and a skin biopsy for histology is employed.

If there is fever, blood cultures should be done. A bone marrow examination and bone marrow culture may be useful. If disseminated intravascular coagulation is suspected, a fibrinogen assay and estimation of fibrin degradation products should be done. Platelet function may be assessed by clot retraction tests. Spleen and liver scans and bone scans may be needed. A CT scan of the abdomen and pelvis may also be necessary. Skin, muscle, and even kidney biopsies are often done to complete the workup.

Dr.Megan Ralf

A Medical laboratory Scientist who devoted his life to medical and laboratory sciences, writes his everyday expertise dealing with various pathological conditions through laboratory diagnosis of different body fluids, also participating in many workshops for first aids, infection control, and urgent care. Also Dr Megan Ralf coaching many medical teams.

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