prothrombin time

What are the recommended prothrombin time values?

If you want to know the recommended values ​​for prothrombin time in blood and what factors can alter these values, refer to our guide on: prothrombin time in normal blood
What do high or elevated blood prothrombin time values ​​indicate?

Elevated levels of prothrombin time indicate a problem with blood clotting; that is, it takes a long time for blood to clot to close a bleeding (a wound), and therefore there is excessive bleeding.

Elevated prothrombin time levels are often due to:

Liver (liver) problems such as cirrhosis or hepatitis.
Lack of vitamin K in the diet.
Disseminated intravascular coagulation.

The prothrombin test is also used to monitor the appropriate dose of oral anticoagulant medications (such as warfarin or acenocoumarol) in those who take them to prevent strokes, although the normalized INR is usually more practical.

Elevated prothrombin time levels usually mean:

Slightly elevated levels (13 - 16 seconds in adults):

Prothrombin time levels are slightly elevated. On some occasions, it may be simply due to the components used to perform the coagulation test and not suppose any notable alteration.

Check with your doctor if you have other symptoms in case some other coagulation tests are needed.
Moderately elevated levels (16-20 seconds in adults):

Prothrombin times are moderately high, and you should consult your doctor.

If vitamin K is administered through intravenous pricks and the prothrombin time returns to normal in about three days, a malabsorption or vitamin K deficiency. If it does not return to normal, it is usually a liver problem (liver).

Another possible cause may be disseminated intravascular coagulation if it presents with low fibrinogen and lower than normal platelets and high activated partial thromboplastin time.
Excessively high levels (20 - 50 seconds in adults):

Prothrombin time levels are excessively high and may correspond to a liver problem (cirrhosis, hepatitis) if GOT and GPT transaminases are elevated.

It may also be due to acute disseminated intravascular coagulation (fibrinogen and low platelets and high activated partial thromboplastin time).

In any case, you must go to your doctor to reverse the situation as soon as possible since values ​​above 30 seconds can cause bleeding that isn't easy to control.
Levels much higher than usual (> 50 seconds in adults):

Prothrombin time levels are much higher than usual and can correspond to severe liver failure, leading to significant health problems.

Likely, the liver does not function properly, and it is convenient to study the degree of hepatic encephalopathy, the serum creatinine level and the arterial pH for a more precise diagnosis.

What can cause an increase in prothrombin time in the blood?

Among the leading causes, which without being a disease in itself, can increase prothrombin time levels are:

Alcohol
Vitamin K deficiency
Diarrhea
Vomiting
Medicines
    Antacids
        Cimetidine
    Antiarrhythmics
        Amiodarone
    Antibiotics
        Metronidazole
        Tetracyclines
    Anticancer
        Asparaginase
    Anticoagulants
        Acenocoumarol
        Dabigatran
        Dicumarol
        Heparin
        Warfarin (Coumarin)
    Antidepressants
        Cholestyramine
    Aspirin
    Fibrates
        Clofibrate
    Uricosuric
        Allopurinol

Surgical pathology in pediatrics represents a frequent cause of care in daily practice. At present, it is accepted in case of scheduling a minor surgery or an outpatient procedure, the request of complementary examinations as a screening of coagulation disorders only in cases in which a family history of coagulopathy or a suggestive clinical history and physical examination is identified of a bleeding disorder, or if the genetic information about the biological family is not evaluable1-3. The level of evidence that supports these recommendations is based on observational studies, but not on randomized clinical trials, which generates controversy when applying these recommendations, especially in facilities with limited resources and in populations with a high prevalence of anemia and malnutrition. that could have repercussions and in a certain way differ from the population studied in the studies4-15 as mentioned above. Knowing these data will provide valuable information during the pediatric preoperative evaluation and allow cost / beneficial decisions to be made for the patients and the institution.

The purpose of this study is to find out the usefulness of PT and APTT in preoperative screening for coagulopathies in children undergoing outpatient surgical interventions or minor scheduled surgeries in the surgery department of the Hospital del Niño Manuel Ascencio Villarroel (HNMAV)

Material and methods

A single-center, prospective, observational study was designed in the pediatric surgery area of ​​the HNMAV, the only public sector hospital of 3rd level of complexity with this service, a sample size of 69 patients, was established, considering a margin of error of 5%, and 95% confidence for a finite universe of 321 minor and scheduled surgeries; were recruited from January 2019 until the sample was completed in June 2020. Patients with no previous comorbidities (known liver, hematological, oncological or nutritional), outpatient procedures or minor surgeries, low estimated bleeding risk, without medication were included in the study that interferes with clotting.

The data collections were carried out in two stages:

Time 1: During the preoperative pediatric outpatient evaluation or the first day of hospitalization, the following measurements were performed:

    Filling in the questionnaire suggested by Rapaport 1

    Search and record of clinical findings suggested by Chee2.

    Request and record TP, APTT, platelet test results, and others suggested by the treating surgeon or anesthesiology team.

Time 2: Early and late postoperative period

    Registry of bleeding complications early (hours) and late (days) after surgery

    Record of laboratory costs, medication and blood products consumed by the patient to correct alterations in the correlogram.

The data were analyzed with the IBM statistics SPSS v25 program, performing descriptive statistics of central tendency and bivariate analysis of the linear correlation between the variables studied and the results (hospital outcomes and costs).

The HNMAV bioethics committee approved the study in October 2018, as it was a descriptive study without intervention in humans, the use of specific, informed consent was avoided, and all the ethical considerations suggested by the committee were taken into account.