Hematocrit Test: Uses, Procedure, and Results

What is hematocrit?

Hematocrit is the percentage of red blood cells in the total blood volume. Red blood cells are vital to your health. Imagine them as the subway system of your blood. They transport oxygen and nutrients to various locations in your body. For you to stay healthy, your body needs to have the correct proportion of red blood cells.

Your doctor may order a hematocrit, or Hct, test if they think you have too few or too many red blood cells.

A hematocrit test can help your doctor diagnose you with a particular condition, or it can help them determine how well your body is responding to a certain treatment. The test can be ordered for a variety of reasons, but it’s most often used to test for:

• anemia
• leukemia
• dehydration
• dietary deficiencies

If your doctor orders a complete blood count (CBC) test, the hematocrit test is included. Other tests in a CBC are a hemoglobin and reticulocyte count. Your doctor will look at your overall blood test results to gain an understanding of your red blood cell count.

Learn more: CBC (complete blood count) »

First you will receive a blood test. Afterward, it will be sent to a laboratory for evaluation.

Blood sample

A medical provider will need a small sample of blood to test your hematocrit. This blood can be drawn from a finger prick or taken from a vein in your arm.

If the hematocrit test is part of a CBC, a lab technician will draw blood from a vein, typically from the inside of your elbow or from the back of your hand. The technician will clean the surface of your skin with an antiseptic and place an elastic band, or tourniquet, around your upper arm to help the vein swell with blood.

They’ll then insert a needle in the vein and collect a blood sample in one or more vials. The technician will remove the elastic band and cover the area with a bandage to stop the bleeding. A blood test can be slightly uncomfortable. When the needle punctures your skin, you might feel a prick or pinching sensation. Some people also feel faint or lightheaded when they see blood. You may experience minor bruising, but this will clear up within a few days. The test will take only a few minutes, and you can resume everyday activities after it’s finished. Your sample will be sent to a lab for analysis.

Evaluation

In the laboratory, your hematocrit is evaluated using a centrifuge, which is a machine that spins at a high rate to cause the contents of your blood to separate. A lab specialist will add a special anticoagulant to keep your blood from clotting.

When the test tube is taken out of the centrifuge, it will have settled into three parts:

• red blood cells
• anticoagulant
• plasma, or the fluid in your blood

Each component will settle in a different part of the tube, with the red blood cells moving to the bottom of the tube. The red blood cells are then compared to a guide that tells what proportion of your blood they make up.

While the laboratory that tests the blood sample may have its own ranges, generally accepted ranges for hematocrit depend on your gender and age. Typical ranges are as follows:

• adult men: 38.8 to 50 percent
• adult women: 34.9 to 44.5 percent

Children ages 15 and under have a separate set of ranges, as their hematocrit levels change rapidly with age. The specific lab that analyzes the results will determine the normal hematocrit range for a child of a certain age.

If your hematocrit levels are too low or too high, it can indicate various problems.

Low hematocrit levels may be a sign of:

• bone marrow diseases
• chronic inflammatory disease
• deficiencies in nutrients such as iron, folate, or vitamin B-12
• internal bleeding
• hemolytic anemia
• kidney failure
• leukemia
• lymphoma
• sickle cell anemia

High hematocrit levels can indicate:

• congenital heart disease
• dehydration
• kidney tumor
• lung diseases
• polycythemia vera

Before getting the test, let your doctor know if you’ve recently had a blood transfusion or are pregnant. Pregnancy can decrease your blood urea nitrogen (BUN) levels due to increased fluid in your body. A recent blood transfusion can also affect your results. If you live at a high altitude, your hematocrit levels tend to be higher due to reduced amounts of oxygen in the air.

Your doctor will likely compare the results of your hematocrit test to the other parts of the CBC test and your overall symptoms before making a diagnosis.

A hematocrit test is not associated with any major side effects or risks. You may have some bleeding or throbbing at the site where the blood is drawn. Let your doctor know if you experience any swelling or bleeding that doesn’t stop within a few minutes of pressure being applied to the puncture site.

How is Polycythemia Vera Treated?

Polycythemia vera (PV) doesn’t have a cure. However, treatments can help control the disease and its complications. PV is treated with procedures, medicines, and other methods. You may need one or more treatments to manage the disease.

Goals of Treatment

The goals of treating PV are to control symptoms and reduce the risk of complications, especially heart attack and stroke. To do this, PV treatments reduce the number of red blood cells and the level of hemoglobin (an iron-rich protein) in the blood. This brings the thickness of your blood closer to normal.

Blood with normal thickness flows better through the blood vessels. This reduces the chance that blood clots will form and cause a heart attack or stroke.

Blood with normal thickness also ensures that your body gets enough oxygen. This can help reduce some of the signs and symptoms of PV, such as headaches, vision problems, and itching.

Studies show that treating PV greatly improves your chances of living longer.

The goal of treating secondary polycythemia is to control its underlying cause, if possible. For example, if the cause is carbon monoxide exposure, the goal is to find the source of the carbon monoxide and fix or remove it.

Treatments To Lower Red Blood Cell Levels

Phlebotomy

Phlebotomy (fle-BOT-o-me) is a procedure that removes some blood from your body. For this procedure, a needle is inserted into one of your veins. Blood from the vein flows through an airtight tube into a sterile container or bag. The process is similar to the process of donating blood.

Phlebotomy reduces your red blood cell count and starts to bring your blood thickness closer to normal.

Typically, a pint (1 unit) of blood is removed each week until your hematocrit level approaches normal. (Hematocrit is the measure of how much space red blood cells take up in your blood.)

You may need to have phlebotomy done every few months.

Medicines

Your doctor may prescribe medicines to keep your bone marrow from making too many red blood cells. Examples of these medicines include hydroxyurea and interferon-alpha.

Hydroxyurea is a medicine generally used to treat cancer. This medicine can reduce the number of red blood cells and platelets in your blood. As a result, this medicine helps improve your blood flow and bring the thickness of your blood closer to normal.

Interferon-alpha is a substance that your body normally makes. It also can be used to treat PV. Interferon-alpha can prompt your immune system to fight overactive bone marrow cells. This helps lower your red blood cell count and keep your blood flow and blood thickness closer to normal.

Radiation Treatment

Radiation treatment can help suppress overactive bone marrow cells. This helps lower your red blood cell count and keep your blood flow and blood thickness closer to normal.

However, radiation treatment can raise your risk of leukemia (blood cancer) and other blood diseases.

Treatments for Symptoms

Aspirin can relieve bone pain and burning feelings in your hands or feet that you may have as a result of PV. Aspirin also thins your blood, so it reduces the risk of blood clots.

Aspirin can have side effects, including bleeding in the stomach and intestines. For this reason, take aspirin only as your doctor recommends.

If your PV causes itching, your doctor may prescribe medicines to ease the discomfort. Your doctor also may prescribe ultraviolet light treatment to help relieve your itching.

Other ways to reduce itching include:

• Avoiding hot baths. Cooler water can limit irritation to your skin.
• Gently patting yourself dry after bathing. Vigorous rubbing with a towel can irritate your skin.
• Taking starch baths. Add half a box of starch to a tub of lukewarm water. This can help soothe your skin.

Experimental Treatments

Researchers are studying other treatments for PV. An experimental treatment for itching involves taking low doses of selective serotonin reuptake inhibitors (SSRIs). This type of medicine is used to treat depression. In clinical trials, SSRIs reduced itching in people who had PV.

Imatinib mesylate is a medicine that’s approved for treating leukemia. In clinical trials, this medicine helped reduce the need for phlebotomy in people who had PV. This medicine also helped reduce the size of enlarged spleens.

Researchers also are trying to find a treatment that can block or limit the effects of an abnormal JAK2 gene. (A mutation, or change, in the JAK2 gene is the major cause of PV.)

Source: National Heart, Lung, and Blood Institute, National Institutes of Health.

norm in a child, women, men, causes of increased, decreased values ​​in the blood

Hematocrit is one of the blood indicators that registers the total volume of all formed elements, and these are erythrocytes, leukocytes and platelets, in relation to the total volume. Moreover, 99% of the volume of all these elements falls on erythrocytes. The hematocrit (Ht) is expressed as a percentage, but a liter per liter (L/L) can also be selected.

Human blood contains from 36 to 48% of formed elements, it also contains plasma, water, proteins, carbohydrates and salts.

Hematocrit is determined simply: a certain amount of blood is poured into a special tube with graduation, then it is sent to a centrifuge, and at the end of the process, the fraction of the length of the tube that was filled with erythrocyte mass is determined. Also, laboratories now use automatic hematology analyzers that allow you to get data in just a few minutes.

Blood hematocrit norm

The body of an adult healthy person contains about 5 liters of blood. Erythrocytes, leukocytes and platelets cannot be called cells, they do not have the necessary parameters for this. Therefore, they are called formed elements. Different people have different amounts of these elements per liter of blood. For example, according to statistics, the hematocrit in men is higher and equal to 40-41%, sometimes this figure can reach 51%.

Hematocrit in women is slightly lower and usually ranges from 36-42%. The reason for this is such a physiological feature as menstruation. As for the period of pregnancy, here this figure begins to decrease in the second half, and this is also not a pathology.

Hematocrit in children always depends on age, therefore, before drawing conclusions from the analysis, it is necessary to find out how many months or years the baby is. In newborn babies, this figure can be equal to 44-62%, at the age of 3 months it decreases and the figure becomes up to 44%, from 3 months to 1 year the figures can range from 32 to 43%. In the first ten years, Ht in boys can rise to 52%, and in girls it can be at around 35-47%. In subsequent years, the hematocrit norm is equal to the same indicator that is recorded in adults.

Causes of increased hematocrit

Why can it happen that the hematocrit in the blood test is elevated? There are pathological and physiological causes, so before starting any treatment, it is important to understand their origin.

Pathological causes include the following diseases and conditions:

1. Dehydration (dehydration). Due to the fact that the amount of blood that circulates through the vessels decreases, the formed elements are in a more concentrated state. This happens with vomiting, diarrhea, heavy sweating, overheating, lack of fluid.
2. Second and third degree burns. In this case, blisters appear on the body, which are filled with plasma, and it appeared in them from the bloodstream. Therefore, the blood becomes thicker, and the concentration of formed elements increases.
3. Peritonitis, thrombosis or diabetes mellitus.
4. Chronic hypoxia.
5. Regular use of glucocorticosteroids or diuretics.
6. Kidney disease – hydronephrosis.
7. Almost all blood diseases, including leukemia.
8. Polycystic.
9. Heart defects, ischemic heart disease.
10. Erythremia.
11. Many lung diseases, including asthma, bronchitis.
12. Severe bleeding.

However, hematocrit analysis alone is not enough to make an accurate diagnosis, it is not very informative. Therefore, it is often done as part of a general blood test, and further therapy tactics are already built on it, if it turns out to be necessary.

But elevated hematocrit can also be the result of certain physiological phenomena. In this case, deviations of this indicator cannot be considered pathological. High Ht in comparison with the norm is detected in people who smoke constantly and for a long time, which is associated with the development of chronic oxygen starvation of tissues and increased production of red blood cells.

Residents of high mountain regions and mountaineers who spend a lot of time at altitude also have Ht in the range of 51-52%. This is all connected with the same oxygen starvation and the need for the body to compensate for this lack. Also, elevated Ht is typical for athletes who take anabolics that help them gain the required amount of muscle mass.

Manifestations and symptoms of elevated hematocrit

If the hematocrit in the blood is elevated, then this will not necessarily be expressed by certain symptoms. However, it should be remembered that this condition is always expressed by an increase in blood viscosity, which creates a great threat for the formation of blood clots and clogging of both small and large vessels.

If this happens in the coronary arteries, then myocardial infarction develops against the background of thrombosis. If a thrombus forms in the pulmonary artery, then death occurs in 70% of all cases. If the arteries of the brain are affected, then this leads to the development of an ischemic stroke. With thrombosis of the vessels of the legs, gangrene begins to develop.

Therefore, it is important to find out the cause of elevated Ht as soon as possible and start timely treatment.

Reasons for low hematocrit

A decrease in hematocrit can occur without any pronounced symptoms, so this result is usually detected after a blood test and is an unexpected discovery for a person.

The main reasons why the hematocrit may be low are:

• virtually all anemias, including iron deficiency, folate deficiency, B12 deficiency;
• violation of the production of red blood cells due to pathologies of the bone marrow, including oncological ones;
• cirrhosis of the liver;
• diseases of the urinary system;
• hemolysis or destruction of red blood cells;
• chronic bleeding;
• increase in circulating blood volume;
• hyperproteinemia;
• lead intoxication;
• acute infections;
• the use of anticoagulants and similar drugs that affect the composition of the blood.

Decreased hematocrit may have physiological causes. This is work associated with a long stay in one position, starvation or adherence to strict diets, a large amount of fluid that enters the body, alcoholism, the use of large amounts of salt, the period of menstruation.

Manifestations and symptoms of low hematocrit

The reasons for the drop in hematocrit will directly affect what symptoms a person experiences. For example, if it is anemia, then there will be such complaints:

• headache and constant weakness;
• impaired consciousness and breathing;
• dizziness, nausea or vomiting;
• constant thirst;
• lack of strength and exercise intolerance.

If the cause is kidney and urinary system diseases, then there will be complaints about a decrease in the amount of urine excreted, pain in the lumbar region, urination disorder, and changes in blood pressure.

With cirrhosis of the liver, complaints will be of pain in the right side of the abdomen under the ribs, the appearance of spider veins on the skin, indigestion, excessive formation of gases, a feeling of fullness in the abdomen, in advanced cases – internal bleeding.

What tests are needed?

To find out the relative content of all formed elements in the blood, it is necessary to analyze the hematocrit. It is done as part of a general blood test (CBC), when, together with Ht, the number of all elements is calculated, and the ESR is also determined.

Usually, it is with the KLA that a patient’s examination begins to identify a particular disease, or it is carried out for preventive purposes as part of a medical examination, medical examination.

Both venous blood and capillary fingerstick blood can be used for analysis. It is best to take the test in the morning, before breakfast. This allows you to get the right readings that will help the doctor determine if Ht is elevated or low, or its values ​​are within the normal range.

Hemoabdomen. Methods of diagnosis and treatment.

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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.

Diagnosis of Hemoabdomen is 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.