What is a platelet count test. How does it measure blood clotting ability. When should you get a platelet count test. What are the symptoms of abnormal platelet levels. How is a platelet count test performed.

What Is a Platelet Count Test and Why Is It Important?

A platelet count test is a crucial laboratory examination that measures the number of platelets in your blood. Platelets, also known as thrombocytes, are tiny cell fragments that play a vital role in blood clotting. This test is essential for assessing your blood’s ability to form clots and stop bleeding.

Why is this test so important? Abnormal platelet levels can lead to serious health complications:

• Low platelet counts (thrombocytopenia) can result in excessive bleeding
• High platelet counts (thrombocytosis) may cause excessive clotting

Both conditions can have significant impacts on your health, ranging from minor inconveniences to life-threatening situations.

Understanding the Purpose of Platelet Count Testing

Platelet count tests serve multiple purposes in healthcare. They are often included in routine blood work, but they can also be ordered for specific reasons:

• Diagnosing platelet disorders
• Assessing bleeding risk before surgery
• Monitoring the effects of certain medications or treatments
• Evaluating the progression of diseases affecting platelet production

How often should you get a platelet count test? Your healthcare provider will determine the frequency based on your individual health needs. For some, it may be part of an annual check-up, while others with specific conditions might require more frequent testing.

Platelet Count in Routine Health Screenings

Platelet count tests are often included in comprehensive blood panels like the Complete Blood Count (CBC). These routine screenings can provide valuable insights into your overall health and may detect potential issues before symptoms appear.

How Is a Platelet Count Test Performed?

The process of getting a platelet count test is straightforward and minimally invasive. Here’s what you can expect:

1. A healthcare professional will draw a small blood sample from a vein in your arm
2. The sample is sent to a laboratory for analysis
3. Automated laboratory equipment counts the platelets in your blood sample
4. Results are typically reported as the number of platelets per microliter of blood

In some cases, if the automated results are questionable, a manual count using a peripheral blood smear may be necessary for confirmation.

Preparing for Your Platelet Count Test

Generally, no special preparation is required for a platelet count test. However, it’s always best to consult with your healthcare provider beforehand. They may advise you to:

• Fast for a certain period before the test if other blood tests are being done simultaneously
• Inform them about any medications or supplements you’re taking, as some can affect platelet counts
• Avoid strenuous physical activity immediately before the test

Interpreting Platelet Count Results: What Do the Numbers Mean?

Understanding your platelet count results is crucial for assessing your health. But what exactly do these numbers indicate?

A normal platelet count typically ranges from 150,000 to 450,000 platelets per microliter of blood. However, it’s important to note that “normal” can vary slightly between laboratories and individuals.

Low Platelet Count (Thrombocytopenia)

A platelet count below 150,000 per microliter is generally considered low. Thrombocytopenia can be caused by various factors, including:

• Certain medications
• Autoimmune disorders
• Bone marrow problems
• Viral infections
• Excessive alcohol consumption

High Platelet Count (Thrombocytosis)

A platelet count above 450,000 per microliter is typically considered high. Thrombocytosis can result from:

• Infections or inflammatory conditions
• Certain types of cancer
• Iron deficiency anemia
• Recent surgery or trauma
• Genetic factors

It’s crucial to remember that a single abnormal result doesn’t necessarily indicate a serious problem. Your healthcare provider will consider your platelet count in conjunction with other test results and your overall health picture.

Recognizing Symptoms of Abnormal Platelet Levels

While abnormal platelet levels may not always cause noticeable symptoms, being aware of potential signs can help you seek timely medical attention. Let’s explore the symptoms associated with both low and high platelet counts.

Signs of Low Platelet Count

Low platelet levels primarily manifest through bleeding-related symptoms. These may include:

• Easy bruising
• Prolonged bleeding from minor cuts
• Frequent nosebleeds
• Bleeding gums
• Blood in urine or stool
• Unusually heavy menstrual periods
• Petechiae (small, reddish-purple spots on the skin)

If you notice these symptoms, especially if they occur frequently or seem excessive, it’s important to consult your healthcare provider promptly.

Indicators of High Platelet Count

High platelet levels can lead to increased clotting, which may cause:

• Unexplained headaches
• Dizziness or weakness
• Chest pain
• Numbness or tingling in hands and feet
• Pain or swelling in the legs

In some cases, extremely high platelet counts can paradoxically lead to bleeding symptoms similar to those of low platelet counts. This underscores the importance of professional medical interpretation of your symptoms and test results.

The Role of Platelet Count in Disease Diagnosis and Treatment Monitoring

Platelet count tests play a crucial role in both diagnosing various conditions and monitoring the effectiveness of treatments. How does this work in practice?

Diagnostic Applications of Platelet Count Tests

Platelet count tests can help diagnose several conditions, including:

• Blood disorders like thrombocytopenia or thrombocytosis
• Certain types of leukemia
• Autoimmune diseases that affect platelet production or destruction
• Bone marrow disorders

In many cases, abnormal platelet counts serve as an early indicator, prompting further investigation to determine the underlying cause.

Monitoring Treatment Effectiveness

For patients with diagnosed conditions affecting platelet levels, regular platelet count tests are essential for:

• Assessing the effectiveness of treatments
• Adjusting medication dosages
• Detecting potential side effects of therapies
• Monitoring disease progression or remission

For instance, patients undergoing chemotherapy often have their platelet levels closely monitored, as many cancer treatments can affect platelet production.

Factors That Can Affect Platelet Count Results

While platelet count tests are generally reliable, several factors can influence the results. Understanding these can help you and your healthcare provider interpret your test results more accurately.

Lifestyle and Environmental Factors

Certain lifestyle choices and environmental conditions can impact your platelet count:

• Alcohol consumption: Excessive alcohol intake can suppress platelet production
• Altitude: Living at high altitudes can temporarily increase platelet counts
• Exercise: Intense physical activity can cause a temporary increase in platelet count
• Stress: Acute stress can lead to temporary elevations in platelet levels

Medical Conditions and Treatments

Various health conditions and medical treatments can affect platelet counts:

• Infections: Certain viral or bacterial infections can impact platelet production or destruction
• Medications: Some drugs, including antibiotics and blood thinners, can affect platelet counts
• Pregnancy: Platelet counts may decrease slightly during pregnancy
• Autoimmune disorders: Conditions like lupus or rheumatoid arthritis can affect platelet levels

It’s crucial to inform your healthcare provider about any medications, supplements, or recent lifestyle changes before undergoing a platelet count test.

When to Seek Medical Attention for Platelet-Related Concerns

While regular check-ups can help monitor your platelet levels, certain situations warrant immediate medical attention. When should you be concerned about your platelet count?

Emergency Situations

Seek immediate medical care if you experience:

• Unexplained, severe bruising
• Prolonged bleeding that doesn’t stop with pressure
• Blood in vomit or stools
• Sudden, severe headache accompanied by neurological symptoms
• Chest pain or difficulty breathing

These symptoms could indicate a severe platelet disorder or other serious medical conditions requiring urgent attention.

Non-Emergency Concerns

Schedule an appointment with your healthcare provider if you notice:

• Increased frequency of nosebleeds or bleeding gums
• Unexplained bruising or petechiae
• Heavier than usual menstrual periods
• Persistent fatigue or weakness

While these symptoms may not always indicate a platelet disorder, they warrant investigation to rule out potential health issues.

Advancements in Platelet Count Testing and Future Directions

The field of hematology is constantly evolving, with new technologies and methodologies emerging to improve platelet count testing. What are some recent advancements, and what might the future hold?

Current Innovations

Recent advancements in platelet count testing include:

• Automated digital cell morphology systems for more accurate platelet identification
• Flow cytometry techniques for precise platelet counting and characterization
• Point-of-care testing devices for rapid platelet count results
• Advanced algorithms for distinguishing platelets from other blood components

These innovations have improved the accuracy and efficiency of platelet count testing, allowing for faster diagnoses and treatment decisions.

Future Prospects

Looking ahead, several exciting developments are on the horizon:

• AI-powered analysis of blood samples for more precise platelet counting and characterization
• Wearable devices for continuous monitoring of platelet levels in high-risk patients
• Gene therapy approaches for treating inherited platelet disorders
• Personalized medicine strategies based on individual platelet function profiles

These advancements promise to enhance our understanding of platelet disorders and improve patient care in the coming years.

As we continue to unravel the complexities of blood disorders and refine our diagnostic tools, platelet count testing remains a cornerstone of hematological assessment. By staying informed about these tests and their implications, you can take a more active role in your health management and work more effectively with your healthcare providers to maintain optimal well-being.

Platelet Count (PLT) Blood Test

Test Quick Guide

The platelet count test is a lab test that measures the number of platelets you have in your blood. Platelets, also known as thrombocytes, are tiny, round cell fragments that circulate in your blood. They are essential for the formation of blood clots, masses of blood the body forms to stop bleeding.

Platelets are one of three main components of the blood along with red and white blood cells.

Platelet count testing can detect when platelet levels are too low or too high. Low platelet levels make it difficult for the body to form blood clots, which can cause excessive bleeding. High platelet levels can cause too much clotting. Blood clots in the blood vessels can become lodged in the lungs, intestines, brain, or heart, and this can result in serious medical conditions.

About the Test

Purpose of the test

The purpose of a platelet count test is to assess your blood’s ability or inability to clot. While platelet counts are often included on multi-test panels such as the complete blood count, this test can also be done on its own.

The platelet count may be conducted by your doctor as part of routine blood testing. Platelet counts are also ordered to:

• Diagnose a platelet disorder
• Assess the risk of bleeding before surgery
• Monitor you during medical treatments such as blood thinners or chemotherapy

The platelet count is used to diagnose disease and help determine the cause of excess bleeding or clotting. Both high and low platelet counts can have associated risks that can range from not causing any noticeable health problems to being very serious and life-threatening.

A platelet count test is also used to monitor if you have been diagnosed with a clotting condition. Regularly conducting a platelet count allows doctors to check the effectiveness of medications that increase or decrease the blood’s ability to form a clot.

What does the test measure?

A platelet count measures the platelets in your sample of blood with the results reported as a number of platelets per microliter. Measuring a platelet count typically involves analyzing a blood sample using automated laboratory technology. In some cases, automated results need to be confirmed using a peripheral blood smear, a method of manually measuring the number of platelets in a blood sample.

When should I get a platelet count test?

Your doctor may recommend you take a platelet count test during a check-up as part of a broader screening panel such as a complete blood count. They might also recommend platelet count testing if you have symptoms associated with abnormal platelet levels. Low or high platelet counts may or may not cause signs and symptoms. It’s important to speak with your doctor any time you notice health changes that concern you.

Symptoms of low platelet levels

Bleeding is the main sign and symptom of a low platelet count. Early signs of a low platelet count can occur in any part of the body and may include (but are not limited to):

• Purple, reddish, or brown bruising, occurring easily and often
• Small red and purple dots on the skin
• Abnormally prolonged bleeding, including from minor cuts
• Bleeding from the nose or mouth
• Atypically heavy vaginal bleeding, especially during menstruation
• Excessive bleeding during dental work, including flossing or surgery
• Blood in the urine or stool, or bleeding from the rectum

Symptoms of high platelet levels

Signs of high platelet levels are primarily related to blot clots and bleeding. They may include:

• Weakness or dizziness
• Unexpected headache
• Chest pain
• Tingling of the hands and feet
• Pain, swelling, warmth, and/or tenderness in one or both of the lower extremities

In some instances, extremely high platelet counts may result in signs and symptoms that mirror low platelet counts. Signs and symptoms of high platelet levels include:

• Bleeding from many sites of the body at once
• Shortness of breath
• Confusion and changes in memory or behavior
• Fever

Monitoring platelet levels

Your health care provider may also order a platelet count test when monitoring other health conditions. If you have been diagnosed with a disease that puts you at risk for high or low platelets, or if you have had abnormal results on past platelet count tests, your doctor may test you for platelet levels periodically. This allows your doctor to monitor your overall health and assess the effectiveness of treatment.

Finding a Platelet Count Test

How can I get a platelet count test?

Typically, a platelet count test is done by a licensed professional in a health care setting using a blood sample. The test can be conducted on its own or as part of a complete blood count test that is done in a doctor’s office, clinic, laboratory, or hospital.

A platelet count test is normally prescribed by a doctor. Talk with your health care provider if you have symptoms that could be related to abnormal platelet levels or if you are interested in a platelet count test.

You can order a platelet test online with a blood draw at a local lab.

Can I take the test at home?

Currently, there are no at-home testing options available for the platelet count. A medical professional conducts platelet counts and they are analyzed by a laboratory from a blood draw sample in a health care setting.

How much does the test cost?

The cost of a platelet count test depends on whether or not you have insurance and if that insurance plan covers the test. Some other factors that affect the price are the setting of the blood draw and the lab to which the sample is sent.

For details on the expected cost for a platelet count that you may be responsible for, check with your doctor or insurance provider about any associated copays or deductibles.

Taking a Platelet Count Test

The platelet count test requires a blood sample ordered by a doctor that is collected in a medical setting by a licensed professional, such as a phlebotomist.

Before the test

No special preparation is required prior to a platelet count test unless specified by your health care provider. They may order the platelet count by itself, as part of the complete blood count, or along with other blood tests.

If you are receiving more than one blood test, your provider may ask you to not eat anything for a certain amount of time prior to your test. Contact your health care provider for detailed instructions if you have questions or concerns about any test preparation.

During the test

A blood sample for a platelet count is taken from a vein in your arm or forearm by a phlebotomist, a health care professional trained in drawing blood. They tie a tourniquet around the upper part of your arm to increase the blood pressure in the vein so it is easier to find.

They will cleanse your skin around the vein with an antiseptic wipe and insert a needle to draw blood from the vein. Next, they attach a vacuum tube to the needle to help pull blood from the vein and, if drawing blood for multiple tests, they may attach several different tubes.

There may be a brief stinging sensation when the needle is initially inserted into your arm. This pain usually does not last long, and the test itself can be completed in under one minute.

After the test

After the procedure is complete, the phlebotomist will apply folded gauze and an adhesive bandage over the site to reduce bleeding, as well as remove the tourniquet and needle.

The main risk associated with blood draws is local bruising at the site of the needle puncture. This bruising may last longer than usual if you are experiencing low platelets. Because low platelet counts reduce the clotting potential of your blood it may be suggested to keep the bandage on for a specified period of time.

The phlebotomist may ask you to stay at the facility for a few minutes so they can monitor you for dizziness before you return to normal activities including walking and driving.

Platelet Count Test Results

Receiving test results

The results from a platelet count can be available in a few minutes or up to a few days after the blood sample arrives at the laboratory, depending on the equipment that is used.

If not available immediately, a copy of your results may be sent to you by mail or through an electronic health portal. It is also possible that your health care provider may call you to discuss the results, retest, or schedule an appointment to review them together.

Interpreting test results

Results are interpreted in comparison with the test reference range, the results range that is considered to be normal. Platelet test results that fall outside of the reference range indicate that platelet levels may be too low or too high.

The reference range for platelet counts gives a wide range of normal results. This reflects the range in platelet levels that allows most people to function without adverse health issues. Specific reference ranges vary from one laboratory to the next, and your results are considered in the context of your overall health risk factors.

The American Board of Internal Medicine lists a typical platelet count reference range as 150,000 to 450,000 per microliter.

Platelet counts tend to be slightly higher in certain populations, including:

• Females
• Younger people when compared with older people
• Non-Hispanic Black individuals when compared with white individuals

Your doctor may consider retesting if you have significant decreases or increases in your platelet numbers from one test to the next even if they are within the normal range as this may indicate a potential problem.

If you have a platelet count test result that is lower than expected, your doctor will consider whether another condition may be causing or contributing to a decrease in platelets. Some causes and risk factors associated with low platelet counts are:

• Certain cancers
• Aplastic anemia
• Autoimmune diseases and conditions
• Certain medications
• Viral or bacterial infections
• Genetic condition
• Heavy alcohol use
• Pregnancy

Other conditions can cause or increase the risk for high platelet counts:

• Rare genetic conditions
• Bone marrow conditions
• Certain cancers
• Iron deficiency or hemolytic anemia
• Inflammatory disease
• Infections such as tuberculosis
• Adverse medication reactions
• Severe blood loss
• Recovery from low blood platelet counts caused by heavy alcohol use or vitamin B12 or folate deficiency
• Physical activity

Depending on the results of your platelet count test, it is possible that your doctor will order follow-up tests to learn more about your overall health. Commonly ordered follow-up tests include:

• Complete blood count: If your platelet count does not match the context of your symptoms and other test results, your doctor may reorder a complete blood count panel to confirm the results prior to more extensive evaluations or interventions.
• Peripheral blood smear: Automated instrumentation is most often used to measure blood counts, including platelet counts. A peripheral blood smear involves manually analyzing the blood sample under a microscope and can be used to confirm an abnormal result on an automated platelet count.
• HIV or HCV test: Low platelet counts are often seen if you have human immunodeficiency virus (HIV) or hepatitis C virus (HCV) infection. Follow-up testing may be used to rule out or confirm the existence of HIV or HCV as the cause of low platelets.

Other tests may be conducted to diagnose the cause of abnormal platelets. Testing depends on the specific conditions that are suspected. If you receive an abnormal platelet count result, your doctor can help you understand what follow-up testing is recommended for you and why.

It may be helpful to ask your doctor the following questions about your platelet count results:

• Was my test result abnormal? If so, was it abnormally high or low?
• What does my platelet count indicate about my health?
• Are there any diagnoses to be made based on my platelet count results?
• Will any follow-up tests be needed?
• Will I be prescribed medication based on my results?

• Platelet Function Tests
  Learn More
• PTT Blood Test (Partial Thromboplastin Time)
  Learn More
• PT/INR Test (Prothrombin Time and International Normalized Ratio)
  Learn More
• Protein C and Protein S
  Learn More
• CBC Blood Test (Complete Blood Count)
  Learn More
• HIV Testing
  Learn More
• Hepatitis C Test
  Learn More
• Blood Smear
  Learn More
• von Willebrand Factor
  Learn More
• D-Dimer Test
  Learn More

Resources

• National Library of Medicine: Platelet Disorders
• National Library of Medicine: Bleeding Disorders

Sources

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Platelet count Information | Mount Sinai

Thrombocyte count

A platelet count is a lab test to measure how many platelets you have in your blood. Platelets are particles in the blood that help the blood clot. They are smaller than red or white blood cells.

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

Most of the time you do not need to take special steps before this test.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.

Why the Test is Performed

The number of platelets in your blood can be affected by many diseases. Platelets may be counted to monitor or diagnose diseases, or to look for the cause of too much bleeding or clotting.

Normal Results

The normal number of platelets in the blood is 150,000 to 400,000 platelets per microliter (mcL) or 150 to 400 × 10⁹/L.

Normal value ranges may vary slightly. Some labs use different measurements or may test different specimens. Talk to your health care provider about your test results.

What Abnormal Results Mean

LOW PLATELET COUNT

A low platelet count is below 150,000 (150 × 10⁹/L). If your platelet count is below 50,000 (50 × 10⁹/L), your risk for bleeding is higher. Even every day activities can cause bleeding.

A lower-than-normal platelet count is called thrombocytopenia. Low platelet count can be divided into 3 main causes:

• Not enough platelets are being made in the bone marrow
• Platelets are being destroyed in the bloodstream
• Platelets are being destroyed in the spleen or liver

Three of the more common causes of this problem are:

• Cancer treatments, such as chemotherapy or radiation
• Drugs and medicines
• Autoimmune disorders, in which the immune system mistakenly attacks and destroys healthy body tissue, such as platelets

If your platelet count is low, talk to your provider about how to prevent bleeding and what to do if you are bleeding.

HIGH PLATELET COUNT

A high platelet count is 400,000 (400 × 10⁹/L) or above.

A higher-than-normal number of platelets is called thrombocytosis. It means your body is making too many platelets. Causes may include:

• Iron deficiency
• After certain infections, major surgery or trauma
• Cancer
• Certain medicines
• Bone marrow disease called myeloproliferative neoplasm (which includes polycythemia vera)
• Spleen removal (splenectomy)

Some people with high platelet counts may be at risk for forming blood clots or even bleeding too much. Blood clots can lead to serious medical problems.

Risks

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another, and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Multiple punctures to locate veins
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Iancu-Rubin C, Cantor AB. Thrombocytopoiesis. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 29.

Schafer AI. Approach to the patient with bleeding and thrombosis. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 162.

Last reviewed on: 2/2/2023

Reviewed by: Mark Levin, MD, Hematologist and Oncologist, Monsey, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

If an operation is to be done… — Unimed in Moscow

From the archive of the Novosti A/O Unimed newspaper

Gulidova O.V.

Experienced surgeons know that even when using well-established technologies and tactics for managing an operating patient, the doctor is not immune from emergencies. Of particular danger are surgical and postoperative hemostasiological complications, which manifest themselves in the form of bleeding or thrombosis.

The risk of postoperative thromboembolism increases with increasing age of patients, types, severity and duration of surgical interventions, the background state of the hemostasis system (the presence of hereditary or acquired thrombophilic conditions, vascular diseases and hemorheological disorders), the presence of diseases that create a particularly high predisposition to thrombosis – varicose veins veins, hyperlipidemia and atherosclerosis, diabetic angiopathy, malignant neoplasms (oncothrombosis), etc.

A special group of risk factors are hereditary and acquired (secondary) thrombophilias, among which forms characterized by polyglobulia (high hematocrit and hemoglobin levels in the blood), hyperthrombocytosis (more than 450-500´10 ⁹ /l), hyperaggregation of platelets, anomalies of coagulation factors, especially factors V and II, making them resistant to physiological anticoagulants, deficiency of the latter (antithrombin III, proteins C and S) and components of the fibrinolysis system, antiphospholipid syndrome.

Increase the risk of thrombosis and some medications – taking many hormonal contraceptives and a number of anticancer drugs, in some patients – heparin therapy (the so-called “heparin thrombotic thrombocytopenia”, GTT), etc.

Accounting for all of the listed risk factors separately and together allows for timely targeted prevention of thromboembolism. The groups of people with a very high risk of such thromboembolism, regardless of all other factors, include patients undergoing orthopedic operations on the lower extremities, including arthroplasty, operated on for visceral cancers, patients with any type of thrombophilia and with a history of lower extremity vein thrombosis.

The risk of arterial thromboembolism is especially high in patients with atherosclerosis who have had NCC and strokes in the past, with high blood pressure, paroxysmal or persistent atrial fibrillation, after commissurotomy and implantation of artificial heart valves, as well as with aneurysms of the main arteries. This risk is exacerbated by certain thrombophilias, hyperhomocysteinemia, diabetes, obliterating diseases of the arteries of the lower extremities. With a number of these types of pathology, there is a high risk of developing both arterial and venous thromboembolism. In the prevention of all these thromboses and embolisms, anticoagulants, inhibitors of platelet aggregation, as well as agents that increase endothelial thrombosis resistance and improve blood rheology, play a leading role, and in the treatment of already formed thrombi, thrombolytics in combination with anticoagulants and antiaggregants.

Based on the foregoing, it is clear that the success of the operation depends on how accurately the hemostatic status of the organism is established, on the preparedness of the patient for surgical intervention. The effectiveness of the preoperative examination is entirely determined by the joint coordinated work of the attending physician and the doctor of the clinical diagnostic laboratory.

The meaning of a high-quality preoperative coagulogram is seen in determining not individual trends – a decrease or increase in fibrinogen, the detection of a hyper- or hypocoagulation shift, which in itself is not sufficiently informative, but diagnostics based on known algorithms for the most common syndromes in the clinic, selection of patients for grouping the risk of developing postoperative thromboembolism, monitoring the conduct of antithrombotic, anticoagulant therapy, identifying the risk of bleeding, etc. In other words, the laboratory is faced with the task of finding, with the help of a minimum number of tests, the shortest path to a diagnosis, abandoning the little useful one-type examination of patients with different types of pathology.

And so, the initial preoperative examination of the patient includes a set of tests showing how likely the development of a thrombotic or hemorrhagic complication in the examined patient and what preventive measures or additional studies are needed.

Bleeding risk assessment

Thrombosis risk determination

A competent doctor in a diagnostic laboratory is the first assistant to a surgeon. What is not visible to the eye, those processes that have not yet given clinical signs of pathology, have already manifested themselves in laboratory tests. The CDL doctor does not see the patient, but he can very accurately characterize his hemostatic status. Here, the attending physician is required to correctly formulate the task – the purpose of the examination. Be sure to indicate the presence of hemorrhagic (nose, uterine or other bleeding), and / or thrombotic manifestations. Give information about the ongoing treatment that can affect the parameters of hemostasis, their dosages and the timing of the last administration. This information will allow you to make a correct conclusion. If abnormalities are detected in screening tests, a decision is made on preventive preoperative measures or on the need for additional laboratory testing to clarify the cause of coagulation abnormalities. Let us consider in more detail the clinical interpretation of the indicators of the main tests.

Determination of the platelet count

During surgical operations complicated by bleeding, disturbances in the system of vascular-platelet hemostasis in most cases are caused not by a violation of aggregation or other functional properties of platelets, but by the presence of thrombocytopenia of one degree or another (see Table 1). Normally, these cells live in the body for 7-10 days. A decrease in the number of platelets can occur due to many processes.

Reduced platelet production cause adenovirus infections, some antibiotics, liver diseases, ionizing radiation, megaloblastic anemia, tumor diseases, hereditary pathologies of platelet formation (Fanconi, Wiskott-Aldrich, Bernard-Soulier syndromes, May-Heglin anomaly). Increased destruction of platelets occurs in autoimmune diseases, prosthetic heart valves, extracorporeal circulation. The number of platelets can decrease sharply when they are intensive consumption with DIC, thrombotic thrombocytopenic purpura. It should be borne in mind that in women during menstruation, the number of platelets can decrease up to 25-50%.

Activated partial thromboplastin time (APTT)

This is the most valuable of the general tests, revealing exclusively plasma defects in the intrinsic factor X activation system. Prolongation of APTT indicates the predominance of hypocoagulation. For all cases of detecting an extended APTT, an additional examination is necessary to establish the cause and choose methods for correcting and preventing possible bleeding.

Prolongation of APTT with normal prothrombin and thrombin time is observed only with deficiency or inhibition of factors VIII, IX, XI, XII, as well as prekallikrein and kininogen.

Corrective tests are performed in the laboratory for differential diagnosis. When confirming the deficiency of any factor, it is necessary to evaluate its activity in%. To perform operations, the minimum hemostatic level of factors VIII, IX, XI is 25%, with a lower activity of one of the factors, the risk of postoperative bleeding is extremely high.

In the absence of a positive result in corrective tests, an examination for the detection of lupus anticoagulant is necessary.

Deceleration of coagulation (both APTT and prothrombin test ) is observed with a deficiency of X, V, II factors, and under the influence of indirect anticoagulants.

Prolongation of APTT, prothrombin and thrombin time is observed with deep hypofibrinogenemia, treatment with fibrinolysis activators and during treatment with heparin. It is known that patients can be with increased and decreased sensitivity to heparin. To resolve the issue of tolerance to heparin, the APTT is re-determined 1 hour before the next injection. If the APTT is more than 2 times higher than normal, hypersensitivity is noted.

Determination of soluble fibrin (RF or RFMK)

The end result of blood clotting is the known thrombin-induced transformation of fibrinogen into fibrin. In a number of pathologies characterized by intravascular coagulation (DIC, thrombosis, thrombophilia), an increased amount of intermediate products of fibrinogen transformation into fibrin circulates in the blood – fibrin monomer and its oligomers, referred to as soluble fibrin (RF) or soluble fibrin-monomeric complexes – RFMK. Determination of an increased amount of soluble fibrin in plasma is of great diagnostic value, since this protein is a marker of thrombinemia and intravascular coagulation.

Paracoagulation tests, ethanol and protamine sulfate, have traditionally been used to detect MFMC in the clinic. However, they are not informative enough, give false positive results in hyperfibrinogenemia and false negative in hypofibrinogenemia, and only qualitatively reflect the process of transformation of fibrinogen into fibrin. Many researchers consider these tests obsolete and out of use. In recent years, a paracoagulation ortho-phenanthroline test (PT) has been developed and widely used, reflecting the content of soluble fibrin in plasma and the presence of thrombinemia. Approbation of this test in many laboratories has shown that FT allows quite reliably not only qualitatively, but also quantitatively determine the content of soluble fibrin in plasma, including in the conditions of express diagnostics. This opened up prospects for a more accurate assessment of the severity of intravascular coagulation and dynamic monitoring of the effectiveness and sufficiency of therapy for DIC and thrombosis.

Prothrombin test

The synthesis of prothrombin complex factors occurs in the liver with the participation of vitamin K. Indirect anticoagulants inhibit the final stage of synthesis in hepatocytes (carboxylation) of vitamin K-dependent coagulation factors. The efficacy and safety of AEDs are monitored by the indications of a standardized prothrombin test, which should be performed taking into account the sensitivity index of the thromboplastin used in the test (ISI) to depression of prothrombin complex factors. Currently, the Russian Federation produces several thromboplastins standardized according to ISI, which is indicated on the packages of this reagent. For different thromboplastins, this index varies from 1.1 to 1.5, which is taken into account when calculating the international normalized ratio (INR), which guides when choosing the right doses of AED. INR is calculated using the following formula:

INR = (PV of patient plasma/ PV of control normal plasma) ^ISI

. Currently, a number of countries produce coagulometers that immediately give the result of a prothrombin test for INR. This greatly simplifies the control of dosages of AEDs, allows you to more often evaluate the effect of these drugs, avoiding their overdose.

Antithrombin III activity

It should be taken into account that the anticoagulant and antithrombotic effects of heparins are realized by their complex connection with plasma antithrombin III (AT III). Therefore, with a deep deficiency of AT III, the effect of these drugs is sharply reduced, which is observed in thrombophilia due to AT III deficiency and in some consumption coagulopathy. This decrease in the effectiveness of heparins can be temporarily reversed by transfusions of fresh frozen plasma that contains AT III, or by intravenous administration of AT III concentrate.

To conduct a full-fledged preoperative coagulological examination in each health facility, there is no need to purchase extra expensive equipment and reagents. Today, domestic manufacturers produce high-quality modern devices and diagnostic kits for the study of all parameters of the hemostasis system. Two-channel programmable optical-mechanical coagulometers Minilab 701 and Minilab 704 are currently operating in more than 300 clinics in the country. The well-known in our country and CIS analyzers of platelet aggregation Biola LA 230 allow you to get complete information about the functional activity of platelets based on the results of spontaneous and induced aggregation, study of the factor Willebrand, counting the number of platelets, determining the platelet shape factor. All devices are open to reagents from both domestic and foreign manufacturers, which gives Russian laboratories ample opportunities for accurate and timely diagnosis of hemostasis parameters, especially if an operation is to be performed…

First blood | Such Cases

• Chronic and incurable diseases
• Drama
• How it works

• 
  05. 08. 2020

Even doctors sometimes make mistakes in orphan diseases. Patients sound the alarm themselves, look for specialized specialists, get themselves referrals for tests, control their performance, delve into the reasons, and discuss their prospects in thematic communities on VKontakte. “Takie Dela” figured out what to do and what to expect if you live in Russia and have a rare disease – ITP, primary immune thrombocytopenia

Sudden death is not worth waiting for – before bleeding in the gastrointestinal tract or brain, hematomas appear on the body, all mucous membranes bleed, platelets fall below 10 thousand. “These situations develop quickly and always require emergency hospitalization. That is why the goal of treating a patient with ITP is to achieve a stable, safe platelet level (>30-50 thousand),” explains Dr. Zotova. But sometimes the disease immediately starts with serious blood loss.

“Wouldn’t have saved anyone”

“I had a sudden uterine bleeding, I was admitted to the hospital – and they found a decrease in platelets. They put me on hormone therapy, it helped only while I was taking the pills. I took a break, went to rest, when I returned, I already had bruises and 7 platelets. The doctors insisted [on the removal of the spleen], I removed it. She went into remission for two years, platelets were 80-120. By that time I was already married and wanted a child. At the fifth month of pregnancy, platelets dropped to 10 thousand, there was a risk of fetal loss. If bleeding had happened, no one would have been saved, ”says Valeria.

After giving birth, she needed to continue taking hormones, but she couldn’t: the side effects were too tormenting. “I had a “lunar” [edematous] face, a [fatty] hump, everything was swollen, my joints hurt. When I stopped taking the pills, it all went away. It was my decision, I myself found a cancellation scheme on the Internet and canceled.

It is possible not to be treated and hope that there will be no next exacerbation, but not for long. Valeria stayed without drugs for two years, and then again ended up in the hospital with uterine bleeding: “I lost a lot of blood, I had zero platelets. I lost consciousness, I vomited, I could not get up. Clots came out of me. It was scary. I could not come to my senses, I fell. I was shaking, my blood pressure was high. They took me away in an ambulance.” Now Valeria is being treated, observed and is waiting for remission. This is the best thing a person with ITP can do.

“Wait”

ITP cannot be cured. You can only maintain a safe level of platelets – for everyone it is different. Synthetic hormones are the first line of therapy. Their job is to suppress the immune system. The second line (for those who have not been affected by the first line) triggers the natural hormone responsible for the production of platelets, thrombopoietin, by interacting with its receptor. These drugs are called thrombopoietin receptor agonists and work in 85-90 percent of patients. The unresponsive 10 percent have their source of immune cells, the spleen, removed. Both methods have serious side effects: bacterial and viral infections stick to the body deprived of the spleen, the use of agonists in some cases excludes pregnancy, since the drugs are harmful to the fetus. But it was agonists, according to Dr. Zotova, that “made a revolution” in the treatment of chronic ITP. “Some patients (about 30 percent) on agonists go into remission, free of therapy, when platelets are kept at a safe level, nothing bleeds, and treatment can be stopped without resorting to long-term hormone therapy and preserving the spleen,” explains the doctor.

Agonists are expensive and given to patients at a discount. That is why hormones are considered the first line of therapy. The president of the All-Russian Society of Hemophilia, lawyer Yuri Zhulev, is sure that the problem is that the regional authorities are responsible for drug provision. “In the regions they often proceed from the financial component. It is easiest to first treat with hormones, then remove the spleen, and only then, if problems continue, transfer to this group of drugs [agonists]. Patients are actively encouraged to remove the spleen,” says Zhulev.

Abrupt withdrawal of agonists and hormones is life threatening. But sometimes nothing depends on the patient. “We had a delay with our [health] department, the drug was not supplied. The child was without treatment for a month. And [try] to explain to our doctors. They said: “Wait.” How can she wait? God forbid, internal bleeding, ”says Kira’s mother Elena.

“It’s completely illegal”

The health of a person with ITP is directly related to geography. According to Zhulev, there are practically no problems in economically prosperous regions, while in poorer regions, patients are forced to beat out vital drugs for themselves through the courts. As a result, local authorities often purchase the drug at a minimum – for reporting, so that it lasts for a couple of months. People who have been on hormones all this time and have been treated with everything they have at hand start saving the drug by reducing dosages, and you can forget about high-quality treatment and the chances of remission.

Sometimes the problem is not even that the agonist is not in the pharmacy, but that a prescription has not been issued for it: the electronic system simply will not allow this if the drug has not arrived at the warehouse. Zhulev calls this a violation of the law and advises in such cases to complain to the regional Ministry of Health, Roszdravnadzor, the prosecutor’s office, and patient organizations. If it doesn’t work, sue. “We are citizens of one country, and laws should be the same for everyone. Interruptions or refusal of treatment is a terrible, very hard life, ”says the lawyer.

Left: View from Elena’s room in her parents’ apartment in Krasnoyarsk. Right: Elena, Krasnoyarsk

Photo: Tatyana Tkacheva for TD

Zhulev is sure that money for agonists should be allocated from the federal budget, this is the only way to reduce the cost of drugs. To do this, it is necessary that ITP be included in the program of high-cost nosologies [state funding of the most expensive treatment], according to which the Ministry of Health of the Russian Federation holds centralized auctions every year with a nationwide volume of purchases. There are far more reasons to demand low prices than in regions with two or three patients. There is no decision yet to include ITP in the program, but the lawyer and his colleagues do not give up: “We have repeatedly appealed [to the president] and hope for him. ITP, unfortunately, did not fall into either the first or the second wave of expanding the list of high-cost nosologies. The arguments are as follows: there are many adults among the patients, and we have an emphasis on children. But adults also deserve the right to a quality life.”

“I had to get myself analyzed”

“It is not clear how long you have to live with this sore. If we don’t know the cause, then we don’t know how serious it is. <...> It is expensive for [government clinics] to buy reagents for analysis. I did a lot of tests for my own money,” says Maria* from Krasnoyarsk. “I had to get myself an analysis for a bone marrow puncture from the thigh, because my local hematologist did not want to send me for this procedure.” Primary immune thrombocytopenia is a diagnosis made “on the contrary”, excluding all other causes of a drop in platelets, from HIV and hepatitis C to rheumatoid arthritis, SLE [systemic lupus erythematosus affecting connective tissues] and oncology. These studies are prescribed in the National Clinical Guidelines for the Diagnosis and Treatment of ITP in Adults and are required by everyone under the CHI policy, but in reality, success again depends on the region and the doctor.

Yury Zhulev explains how and why to defend his right to free tests: “Even if there is no opportunity to carry out any diagnostics in the region, the authorities have two ways: they can sign an agreement with a commercial structure and send patients there, paying for their analysis , or within the framework of the CHI system, send the patient to another region or to the federal center, also paying for such a study. You can complain to your insurance medical organization [its name can be found in the territorial CHI fund], Roszdravnadzor, call the free hotline of the All-Russian Hemophilia Society. Our task is to pose problems and insist on their solution, and then reagents will appear.

***

“You won’t convince me that everything is bad,” this is how Yury Zhulev answers the question of why everything looks so hopeless in the case of ITP. – The way to solve this problem is clear: federalization. The example of other diseases shows that where it occurred, the problem generally goes away. If treated, fully provided with medicines, then people can live a decent life. I am sure that if you take an active position, you can achieve change.”

In anticipation of changes, you can knock on the ITP chat: ask for advice, ask for contacts of familiar specialists and just talk out when things are bad, scary and nothing is clear. There, among the photos of lilac-black bruises, there are stories of remissions.