What is a hematocrit test. How is it performed. What can abnormal hematocrit levels indicate. When should you get a hematocrit test. What are the normal hematocrit ranges for different age groups and genders.

What Is a Hematocrit Test and Why Is It Important?

A hematocrit test is a crucial medical procedure that measures the proportion of red blood cells in your blood. This test is typically part of a complete blood count (CBC) and provides valuable insights into your overall health. Red blood cells, along with white blood cells and platelets, are suspended in plasma, which facilitates blood circulation throughout your body.

The importance of the hematocrit test lies in its ability to detect various health conditions. Abnormal hematocrit levels can indicate blood disorders, dehydration, or other medical issues that require attention. By understanding the percentage of red blood cells in your blood, healthcare providers can better assess your health status and make informed decisions about your care.

Components of Blood and Their Functions

• Red blood cells: Contain hemoglobin, which carries oxygen to organs
• White blood cells: Crucial for immune system function
• Platelets: Essential for blood clotting
• Plasma: Fluid component that helps blood circulate

When Should You Get a Hematocrit Test?

Your doctor may recommend a hematocrit test if you exhibit symptoms of certain medical conditions or as part of routine health screening. Some common reasons for ordering this test include:

• Frequent breathing issues
• Dizziness, lightheadedness, or recurring headaches
• Pale skin
• Cold feet and palms
• Flushed skin or rashes
• Frequent itching and sweating
• Vision problems or double vision
• Persistent fatigue and tiredness

Additionally, if your doctor suspects anemia, blood disorders, or polycythemia vera, they may order a hematocrit test as part of the diagnostic process.

The Hematocrit Test Procedure: What to Expect

The hematocrit test is a quick and straightforward procedure that typically takes 10-20 minutes. Here’s what you can expect during the test:

1. A medical professional will clean the area where blood will be drawn, usually from a vein in your arm.
2. An elastic band may be placed around your upper arm to help the vein swell.
3. A needle will be inserted to draw the blood sample, which may cause a brief pricking sensation.
4. One or two vials of blood will be collected.
5. After the blood is drawn, the site will be covered with a band-aid to promote healing.

The blood sample is then sent to a laboratory for analysis. In the lab, the blood is mixed with an anticoagulant and spun in a centrifuge to separate its components. The technician measures the proportion of red blood cells and compares it to established guidelines to determine the hematocrit percentage.

Preparing for Your Hematocrit Test

How should you prepare for a hematocrit test? Generally, no special preparation is required. However, it’s important to inform your doctor about any medications you’re taking, as some may need to be temporarily discontinued. Always follow your healthcare provider’s instructions and discuss any concerns you may have before the test.

Understanding Hematocrit Test Results: Normal Ranges and Implications

Hematocrit levels vary based on age and gender. Understanding the normal ranges can help you interpret your test results:

• Men: 41% to 51%
• Women: 36% to 44%
• Newborns: 45% to 61%
• Toddlers: 32% to 42%

What do abnormal hematocrit levels indicate? Lower than normal levels may suggest:

• Anemia (insufficient red blood cells)
• White blood cell disorders
• Vitamin deficiencies
• Blood loss

Higher than normal levels could point to:

• Heart diseases
• Lung disorders
• Dehydration

Potential Risks and Side Effects of the Hematocrit Test

Is the hematocrit test safe? While the hematocrit test is generally considered a safe and standard procedure, some individuals may experience minor discomfort or side effects. These can include:

• Slight pain or swelling at the injection site
• Temporary bruising
• In rare cases, infection or irritation if unsterilized needles are used

To minimize risks, ensure that your healthcare provider uses sterilized equipment and follows proper hygiene protocols. If you experience persistent pain, swelling, or signs of infection after the test, contact your healthcare provider promptly.

After the Hematocrit Test: Recovery and Follow-up

What should you expect after a hematocrit test? Most people can resume normal activities immediately after the test. However, if you experience any discomfort:

• Apply gentle pressure to the injection site with a cotton ball to reduce bleeding and discomfort
• Rest for a short period if you feel dizzy (this is rare and usually resolves within an hour)
• Keep the bandage on for a few hours to protect the puncture site

Your healthcare provider will inform you about when to expect your results and schedule any necessary follow-up appointments based on the findings.

Special Considerations: Hematocrit Tests During Pregnancy

Can pregnant women undergo a hematocrit test? Yes, hematocrit tests are safe for pregnant women and are often part of routine prenatal care. During pregnancy, a woman’s blood volume increases, which can affect hematocrit levels. Regular monitoring helps healthcare providers ensure the mother and baby are receiving adequate oxygen and nutrients.

Why are hematocrit tests important during pregnancy? They can help detect anemia, which is common during pregnancy due to increased iron demands. Early detection and treatment of anemia can prevent complications for both mother and baby.

Frequency of Hematocrit Tests During Pregnancy

How often should pregnant women have hematocrit tests? Typically, healthcare providers recommend:

• First trimester: As part of initial prenatal screening
• Second trimester: Around 24-28 weeks
• Third trimester: If anemia is suspected or as part of routine monitoring

However, the frequency may vary based on individual health factors and your healthcare provider’s recommendations.

Interpreting Hematocrit Results in Different Medical Contexts

How do healthcare providers use hematocrit test results in different medical scenarios? The interpretation of hematocrit levels can vary depending on the clinical context:

Anemia Diagnosis and Monitoring

In cases of suspected anemia, how do hematocrit levels help? Low hematocrit levels, especially when combined with low hemoglobin, can confirm anemia. The severity of anemia can be assessed based on how far below normal the hematocrit level is. Follow-up tests may be needed to determine the underlying cause, such as iron deficiency or chronic diseases.

Polycythemia Vera Evaluation

What role does the hematocrit test play in diagnosing polycythemia vera? Consistently high hematocrit levels, along with other blood test results, can indicate polycythemia vera, a condition where the body produces too many red blood cells. Additional genetic tests may be required for a definitive diagnosis.

Dehydration Assessment

How can hematocrit levels indicate dehydration? Elevated hematocrit levels can suggest dehydration, as the blood becomes more concentrated when there’s a lack of fluids. This information is particularly useful in emergency settings or when evaluating patients with heat-related illnesses.

Monitoring Chronic Conditions

For patients with chronic conditions like kidney disease or heart failure, how are hematocrit tests used? Regular hematocrit tests can help monitor the progression of these conditions and the effectiveness of treatments. For instance, in kidney disease, hematocrit levels may decrease as the kidneys’ ability to produce erythropoietin (a hormone that stimulates red blood cell production) declines.

Lifestyle Factors Affecting Hematocrit Levels

What lifestyle factors can influence your hematocrit levels? Understanding these factors can help you maintain healthy hematocrit levels:

Diet and Nutrition

How does diet affect hematocrit levels? A balanced diet rich in iron, vitamin B12, and folate is crucial for maintaining healthy red blood cell production. Vegetarians and vegans may need to pay extra attention to their iron intake through plant-based sources or supplements.

Hydration Status

Why is proper hydration important for hematocrit levels? Dehydration can artificially elevate hematocrit levels by concentrating the blood. Conversely, overhydration can dilute the blood and lower hematocrit levels. Maintaining proper hydration helps ensure accurate test results.

Physical Activity

How does exercise impact hematocrit levels? Regular physical activity, especially endurance training, can lead to a natural increase in hematocrit levels as the body adapts to increased oxygen demands. However, excessive exercise without proper hydration can lead to dehydration and skewed results.

Altitude

What effect does living at high altitudes have on hematocrit? People living at high altitudes often have naturally higher hematocrit levels due to the lower oxygen levels in the air. The body compensates by producing more red blood cells to improve oxygen-carrying capacity.

Technological Advancements in Hematocrit Testing

How has technology improved hematocrit testing? Recent advancements have made hematocrit testing more efficient and accessible:

Point-of-Care Testing

What are the benefits of point-of-care hematocrit testing? Portable devices now allow for rapid hematocrit testing at the bedside or in remote locations. This enables quicker decision-making in emergency situations and improves access to testing in resource-limited settings.

Automated Hematology Analyzers

How have automated analyzers enhanced hematocrit testing? Modern hematology analyzers can perform complete blood counts, including hematocrit, with high precision and speed. These machines can process hundreds of samples per hour, improving laboratory efficiency and reducing human error.

Non-Invasive Techniques

Are there non-invasive methods for measuring hematocrit? Research is ongoing into non-invasive techniques for estimating hematocrit levels, such as using optical sensors or bioelectrical impedance. While not yet widely available, these methods could potentially reduce the need for blood draws in the future.

Hematocrit Test in Relation to Other Blood Tests

How does the hematocrit test complement other blood tests? The hematocrit test is often performed alongside other blood tests to provide a comprehensive picture of a patient’s health:

Complete Blood Count (CBC)

What is the relationship between hematocrit and other CBC components? The hematocrit is a key part of the CBC, which also includes measurements of hemoglobin, white blood cells, and platelets. Together, these tests provide a broad overview of blood health and can help diagnose various conditions.

Mean Corpuscular Volume (MCV)

How does MCV relate to hematocrit? MCV measures the average size of red blood cells. When interpreted alongside hematocrit, it can help differentiate between types of anemia. For example, low MCV and low hematocrit might suggest iron deficiency anemia.

Reticulocyte Count

Why might a reticulocyte count be ordered with a hematocrit test? Reticulocytes are immature red blood cells. A high reticulocyte count with a low hematocrit might indicate that the body is trying to compensate for blood loss or hemolysis (destruction of red blood cells).

Hematocrit Levels in Different Medical Specialties

How do different medical specialties use hematocrit test results? The hematocrit test has applications across various fields of medicine:

Hematology

In hematology, how are hematocrit levels used? Hematologists rely on hematocrit levels to diagnose and monitor blood disorders such as anemia, polycythemia, and leukemia. The test helps in assessing the severity of these conditions and guiding treatment decisions.

Cardiology

Why are cardiologists interested in hematocrit levels? Hematocrit levels can affect blood viscosity, which impacts heart function. High hematocrit levels may increase the risk of blood clots, while low levels could indicate heart failure or other cardiovascular issues.

Nephrology

How do nephrologists use hematocrit test results? Kidney disease can affect red blood cell production, often leading to anemia. Nephrologists monitor hematocrit levels to assess kidney function and manage anemia in patients with chronic kidney disease.

Sports Medicine

What role does the hematocrit test play in sports medicine? Athletes’ hematocrit levels are monitored to ensure optimal performance and detect any abnormalities. Some sports organizations also use hematocrit testing as part of anti-doping measures to detect blood doping practices.

Future Directions in Hematocrit Testing and Research

What does the future hold for hematocrit testing? Ongoing research and technological advancements are shaping the future of hematocrit testing:

Personalized Reference Ranges

How might reference ranges for hematocrit evolve? Research is exploring the development of more personalized reference ranges that take into account factors such as age, gender, ethnicity, and individual baseline levels. This could lead to more accurate interpretations of test results.

Integration with Artificial Intelligence

How could AI enhance hematocrit testing? Artificial intelligence algorithms could potentially analyze hematocrit results along with other health data to predict disease risk or guide treatment decisions more effectively.

Continuous Monitoring

Is continuous hematocrit monitoring possible? Research is ongoing into wearable devices that could potentially monitor hematocrit levels continuously, providing real-time data for patients with chronic conditions or those undergoing intensive medical treatments.

As research progresses, these advancements may lead to more precise diagnoses, personalized treatment plans, and improved patient outcomes. The hematocrit test, while seemingly simple, continues to be a vital tool in modern medicine, evolving alongside technological and medical advancements.

Hematocrit Test – Everything you Need to Know

A hematocrit test measures the proportion of red blood cells in your body. Your blood contains red blood cells, white blood cells, and platelets. Plasma is a fluid that contains red blood cells, white blood cells, and platelets. Plasma helps in blood circulation through your body. Haemoglobin is a protein present in your red blood cells that carries oxygen to all your organs from your lungs. Abnormal hematocrit levels hint at a few medical conditions, including blood disorders and dehydration. 

Why is Hematocrit Test Done? 

A hematocrit test is part of the complete blood count (CBC). It is essential to know the proportion of red blood cells in your blood to assess your health condition better. Your doctor may suggest a hematocrit test if you exhibit symptoms of anemia, a blood disorder, or polycythemia vera, and in any of the following cases: 

• If you suffer from breathing issues frequently
• If you have symptoms like dizziness, lightheadedness, and frequent headaches 
• If you have pale skin
• If you have cold feet and palms
• If your doctor observes flushed skin and rashes
• If you have frequent itching and sweating
• If you experience vision trouble or double vision
• If you experience fatigue and tiredness

Call 1860-500-1066 to book an appointment

Before the Procedure:

The hematocrit test is a quick and straightforward procedure. It is a non-invasive test. 

• Tell your doctor about your medications. Your doctor might ask you to discontinue a few medicines, but this happens in rare cases.  
• Talk to your doctor and get the details of the test. 

During the Procedure: 

Hematocrit test typically takes 10-20 minutes as it is a simple procedure. 

• A medical professional will take a blood sample from your vein or arm. 
• The medical professional will initially clean the surface from where the blood is to be drawn. 
• The lab professional will take blood from a vein on the inside of your elbow. 
• Your lab professional will place an elastic band around the region from where the blood is drawn to avoid swelling of the vein. 
• Your nurse will then insert the needle to draw the blood sample. He/she will take the blood sample in one or two vials. 
• You might initially feel a prickling sensation, but it subsides after a couple of minutes.  
• After taking blood, the lab professional will close the wound with a band-aid to enable better and quicker healing of the swollen wound. 
• Your blood samples will be sent to a laboratory for further examination
• The technician will separate the contents of blood and add an anticoagulant to prevent your blood from clotting. The contents, including red blood cells, plasma, and anticoagulants, will settle separately in the test tube after spinning in a centrifuge. 
• The technician will compare the separated red blood cells with a guide to note the count PERCENTAGE of your red blood cells. 

After the Procedure: 

Hematocrit is a non-invasive test and does not require hospitalization after the procedure. However, if you experience discomfort at the injection site, press the site with cotton to prevent blood flow and reduce the prickling sensation. 

If you feel dizzy, you can rest for an hour after the procedure. This happens only in rare cases, and you will be normal within an hour 

• The hematocrit test is simple. Hence, you can resume your regular activities immediately. 

Hematocrit Test:

Results 

Normal Hematocrit Levels

Your condition is abnormal if your hematocrit results are not in line with the following range. The hematocrit levels usually vary between genders and age groups. 

• Men: 41% to 51%
• Women: 36% – 44%
• New born: 45% – 61%
• Toddlers: 32% – 42% 

A lower hematocrit level indicates any of the following condition: 

• Anemia: Anemia is a health condition where your body produces insufficient red blood cells. 
• White blood cell disorder: A lower hematocrit level may indicate production of an overwhelming number of white blood cells. 
• Vitamin deficiency: The lower hematocrit level may be due to vitamin deficiency. 
• Blood loss: Blood loss can sometimes cause a lower hematocrit level. 

A higher hematocrit level indicates the following conditions: 

• It may be due to heart diseases.  
• A higher hematocrit level may sometimes be due to lung disorders. 
• Dehydration. 

Risks involved 

The hematocrit test is a standard procedure performed to check the proportion of red blood cells in your blood. Hence, it is a safe method. However, you may experience discomfort temporarily. This may include: 

• Slight pain as well as swelling at the site of injection. 
• You may experience infection and irritation at the site of injection sometimes. But this happens only if the needles are unsterilized. So, make sure that your medical helpers use sterilized needles. 

Frequently Asked Questions (FAQs): 

Can pregnant women take this test? 

A hematocrit test is a simple blood test. So, pregnant women can also take it. However, please consult your doctor before going for the test. 

Can older people take a hematocrit test? 

The hematocrit test is a safe procedure. Hence, people of any age group can undergo this test. 

Should I stop taking other medications before the test? 

You do not have to stop your medications. But consult your doctor before the test. In rare cases, he/she may require you to stop your medication temporarily.  

The hematocrit test may not always be accurate. Various factors contribute to inaccurate results, including pregnancy, recent blood transfusion, dehydration, etc. If this happens, your doctor will ask you to undergo the hematocrit test once again. However, this happens in rare cases.

What Do Routine Blood Tests Check For?

Blood tests are among the most common types of diagnostic tests for good reason. The small amounts of blood drawn for the test can help your doctor check for a wide range of issues.

“From checking your cholesterol levels and thyroid function to diagnosing infections, diseases and other conditions, blood tests are often the first step in diagnosing dozens of conditions,” says Fatma Deif, MD, an internal medicine physician at Scripps Clinic Rancho San Diego.

Your doctor typically orders blood tests for you during a physical, checkup or screening for a specific condition, including heart disease, thyroid disease, cancer, diabetes and sexually transmitted infections.

Blood tests are very safe. A phlebotomist uses a needle to takes a sample of your blood, usually from a vein in your arm. You may feel a slight prick when the needle is inserted into the vein. But the test is typically not painful, and the process takes just a few minutes.

A routine complete blood count (CBC) is a lab test that can provide an overview of your health. It can help your doctor look for a specific condition. This test measures several parts of your blood, including:

This test measures the number of red blood cells in your blood. A low count may indicate disorders, such as anemia or blood loss. Red blood cells carry oxygen from your lungs to your entire body.

This test measures the number of white cells in your blood. While blood cells help with immunity, so low counts may be a sign of infection or immune system problems. There are different types of white blood cells; a blood differential test measures each type.

This test measures the number of platelets in your blood. Platelets help your blood clot. Low platelet levels may lead to too much bleeding; high levels may raise your risk of blood clots.

Measures the amount of hemoglobin in your blood. Hemoglobin is a protein that carries oxygen. Low levels can indicate anemia and other disorders.

Measures the proportion of red blood cells in your blood. If you have anemia, your hematocrit may be low, while dehydration may cause it to be high. Hematocrit levels also may signal a blood or bone marrow disorder.

The MCV test measures the average size of your red blood cells. Abnormal levels may indicate a disorder.

A basic metabolic panel (BMP) is a group of tests that measures the various chemicals in your blood. It includes tests for blood glucose, calcium and electrolytes, which are minerals in your blood.

“The BMP gives us a wealth of information about your heart, muscles, bones and organs, such as your liver and kidneys,” says Dr. Deif. “Your doctor may instruct you to fast for several hours or overnight before having some of these tests.”

This test measures the amounts of enzymes, which are proteins in your blood that can indicate tissue damage or disease. There are many blood enzyme tests. One of the most common is used to detect a heart attack and heart muscle damage.

Also called a lipid panel, this test measures your HDL (“good”) and LDL (“bad”) cholesterol levels, as well as your triglycerides, a type of fat. It can provide information about your risk of coronary heart disease. You may need to fast for up to 12 hours before taking this test.

The human chorionic gonadotropin (hCG) test measures the level of hCG hormone in your blood and is used to see if a woman is pregnant. It also may be done to test for breast, lung, uterine or ovarian cancer.

Measures level of ammonia, which is a waste product created when your body breaks down protein. If too much ammonia builds up in your blood, it can result in extreme fatigue, neurological problems, coma or death.

Measures the amount of carbon dioxide in your blood. Abnormal levels may indicate kidney, respiratory or metabolic issues.

Measure your blood’s ability to clot and how long it takes to clot. People who take blood thinning medication, such as coumadin, are given this test to make sure they are taking the correct dosage.

If your doctor recommends a blood test, be sure you understand what the test measures. Check if you need to do anything to prepare for it. Many patients, including at Scripps, can check their blood test results in secure online patient portals.

hemoabdomen. Methods of diagnosis and treatment.

Recommended: Action Plan for 2023

Experimental Therapy Clinic N. N. Blokhin RAMS with OOO “Biocontrol”, Anesthesiological Veterinary Society VITAR
Kuznetsova A.L., Ph.D. Kornyushenkov E.A., Ph.D. Lissitskaya K.V.

The term “Hemoabdomen” and “Hemoperytoneum” means an abnormal accumulation of blood in the abdominal cavity.

Hemoabdomen can be caused by damage to internal organs, rupture of abdominal tumors, or coagulation disorders. Stabilization of patients with Hemoabdomen is non-specific, while specific treatment may vary depending on the cause of the bleeding. If Hemoabdomen is caused by blood clotting disorders, then surgical treatment is contraindicated. Hemoabdomen caused by a tumor process is subject to surgical treatment in the form of excision of this neoplasm (if possible). Patients with intra-abdominal bleeding caused by trauma can often be treated conservatively.

Hemoabdomen is diagnosed based on clinical signs, imaging findings and/or laparocentesis. In the presence of even a small volume of fluid in patients with signs of an acute abdomen, aspiration and analysis of the fluid is indicated. The puncture is carried out according to the 4-square system, retreating 2-3 cm from the navel. Immediate laparocentesis allows diagnosing Hemoabdomen in about 60% of cases. A false positive result can be obtained in the case of puncture of the spleen, liver or other abdominal organs. These causes can be easily ruled out, since blood that has been in contact with the serosa does not clot due to a decrease in the amount of fibrinogen and platelets. With Hemoabdomen, the aspirated fluid is hemorrhagic in nature. The liquid obtained by laparocentesis is divided into portions: 1) to determine hematocrit, cytosis and conduct a cytological study; 2) for biochemical research; 3) if necessary, bacteriological examination. The diagnosis of “Hemoabdomen” can be made if the abdominal hematocrit is equal to or even higher than the hematocrit of the blood. Hemorrhagic fluid with a lower hematocrit can be obtained, for example, in Uroabdomen, peritonitis, ascites, which can be differentiated by biochemical analysis of ascitic fluid. Thus, it is possible to diagnose an injury to the bladder, gallbladder, etc. When used to diagnose peritoneal lavage, a hematocrit >5% in the lavage fluid is an indicator of Hemoabdomen, which can be of great importance in peritoneal dialysis.

Treatment for Hemoabdomen can be either conservative or surgical. Minor abdominal bleeding may occur spontaneously and not be accompanied by severe clinical symptoms. If the patient cannot be stabilized conservatively, surgery is required.

Fluid therapy and analgesia are important therapeutic parts in the management of all patients, regardless of the therapeutic or surgical treatment strategy. Massive abdominal bleeding can lead to the development of hypovolemic shock.

The goal of fluid therapy is to normalize tissue perfusion and oxygen supply in patients with abdominal bleeding. Infusions include bolus administration of 10-20 ml/kg of crystalloid solutions, 5-10 ml/kg of colloids. With massive blood loss (hematocrit 20-25%), hemotransfusion is necessary (whole blood, erythrocyte mass, plasma). The ability of blood products to maintain oxygen supply becomes especially important in the event of an acute loss (up to 35%) of an animal’s blood volume. Allotransfusion is acceptable (provided the bleeding is not caused by cancer) if other blood products are not available. Oxygen therapy is an important part of anti-shock therapy in patients with Hemoabdomen.

An important step to prevent further bleeding is to normalize blood clotting and achieve a blood pressure of approximately 100/60 mmHg. Maintaining this level reduces the risk of rebleeding and ensures adequate tissue perfusion. Coagulation disorders are treated with vitamin K (5 mg/kg loading dose) and plasma (10-15 ml/kg IV). In the event of severe blood loss, plasma may be given as part of bolus fluid therapy. In all other cases, it should be administered within 2-4 hours.

Analgesia is best administered with opioids (eg butorphanol 0.2–0.8 mg/kg) in combination with a continuous infusion of lidocaine. Lidocaine is given as a bolus of 2 mg/kg (cats 0. 5 mg/kg) followed by 30-50 mcg/kg/min (approximately 2-4 mg/kg/h). With prolonged use (more than 24 hours), animals may become sedated and the dose must be reduced. In cats, this pain management tactic is rarely used due to the high toxicity of lidocaine to this species.

Depending on the cause of the Hemoabdomen, patients are treated surgically or non-surgically after stabilization.

Conservative treatment includes fluid therapy, analgesia, oxygen therapy, antibiotic therapy, blood transfusion and is similar in general features to patient stabilization. Careful monitoring of perfusion parameters is necessary.

In case of disease progression, a decision on surgical intervention may be necessary to stop bleeding. Indications for surgery include ongoing symptoms of shock despite fluid resuscitation and analgesia, rapid abdominal expansion, worsening after an initial positive response to conservative therapy, and evidence of continued bleeding on laparocentesis. Animals that are indicated for surgical treatment will require more blood products compared to animals not subject to surgery.

The decision to treat a patient with surgery or medication is not always easy. As mentioned above, some patients with traumatic Hemoabdomen can be treated non-operatively if they do not have other problems that require surgical treatment. Using the hematocrit values ​​obtained during laparocentesis and incidentally taken hematocrit values ​​from peripheral blood, it is possible to differentiate ongoing bleeding from stopped bleeding. When bleeding stops, venous hematocrit will decrease due to the replenishment of intravascular volume with infusion solutions, and after the end of infusion therapy it will remain stable. Compared to venous hematocrit, abdominal hematocrit will remain unchanged. With continued bleeding, venous hematocrit will fall due to infusion therapy, and will not stabilize after its completion. Since further ongoing bleeding in the abdomen will be “thinner” blood, the abdominal hematocrit will also decrease.

Effect of hemolysis on in vitro hemostasis parameters

March 22, 2021

It is generally accepted that in vitro induced hemolysis affects a wide range of tests in biochemistry, immunochemistry and hematology. Most laboratory associations around the world also advise careful and careful handling of samples aimed at determining the parameters of hemostasis. In particular, in the United States of America, the European Union and some countries of Latin America and Asia, the rejection of samples with varying degrees of hemolysis is prescribed in the standards for determining prothrombin time (PT), activated partial thromboplastin time (APTT), D-dimer and a number of others. parameters.

Previous studies have associated the effect of hemolysis with the competitive action of membrane phospholipids released into the blood plasma on activated factor VII (FVIIa) in parallel with thromboplastin. But empirically confirmed data on this theory is not yet available. At the same time, the rejection of hemolyzed venous blood samples leads, at a minimum, to a delay in the results of studies and, as a result, to a delay in making clinical decisions. On the other hand, inaccurate results lead to the need for repeated blood sampling, additional costs for the medical institution for the procedure and the laboratory for testing, and, as a result, again delay in obtaining reliable test results.

The purpose of the study was to test the convergence and reproducibility of the results of studies of hemostasis parameters in “pure” (free hemoglobin concentration ~ 0 g/dL) blood plasma and blood plasma of the same patients with varying degrees of mechanically induced hemolysis.

All studies were carried out in accordance with the approved protocol of the Board of Laboratory Diagnostic Physicians. Blood was drawn into Greiner Vacuettes (Greiner-Bio-One, Monroe, NC) 3.15 ml vacuum tubes containing 3.2% (109mmol/l) buffered sodium citrate. Hemolysis was determined after centrifugation at 2500 rpm. within 15 minutes. All samples were aliquoted in pairs. The concentration of free hemoglobin was measured on a spectrophotometer by the colorimetric method at three wavelengths with maximum absorption at 562, 578 and 598 nm. The percentage of hemolysis was calculated from the concentration of free and total hemoglobin in blood plasma and hematocrit.

The results of the studies showed a correlation between an increase in the concentration of free hemoglobin in the blood plasma and an increase in TT, a decrease in APTT, an increase in the concentration of D-dimer and a decrease in the concentration of fibrinogen. It should also be noted that the shift in the determination of parameters in the direction of increasing wavelength, reduced the relationship between the concentration of free hemoglobin and changes in hemostasis parameters.

Conclusion.

Thus, it can be stated that the concentration of free hemoglobin affects the results of in vitro hemostasis parameters. Even in the standard “five” tests (PT, APTT, Fibrinogen, TB, D-dimer) there are parameters whose detection at some wavelengths and even the minimum degree of hemolysis cannot be considered reliable.

There are two basic solutions to solve this problem:

1. Standardization of the preanalytical stage of laboratory diagnostics in order to reduce the percentage of hemolyzed venous blood samples.

2. The use of automated coagulometers with the HIL-detector module and the possible measurement of hemostasis parameters at wavelengths greater than 660nm.

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