What are the normal hematocrit ranges for adults. How do high and low hematocrit levels impact health. What treatments are available for abnormal hematocrit levels.

What is Hematocrit and Why is it Important?

Hematocrit is a blood test that measures the percentage of red blood cells in a person’s total blood volume. This important metric provides valuable information about overall blood health and oxygen-carrying capacity. Understanding hematocrit levels and ranges is crucial for diagnosing and managing various medical conditions.

The hematocrit test is typically part of a complete blood count (CBC) and is often performed alongside hemoglobin measurements. While hemoglobin measures the oxygen-carrying protein in red blood cells, hematocrit looks at the proportion of red blood cells themselves.

Key Functions of Hematocrit Testing

• Assessing overall blood health
• Detecting anemia and polycythemia
• Monitoring hydration status
• Evaluating response to certain medical treatments
• Screening for blood disorders

Normal Hematocrit Ranges: What’s Considered Healthy?

Normal hematocrit ranges can vary based on factors like age, sex, and even geographic location. However, general guidelines exist for what’s considered a healthy hematocrit level in adults.

Adult Hematocrit Ranges

• Adult Males: 40.7% to 50.3%
• Adult Females: 36.1% to 44.3%

It’s important to note that these ranges may differ slightly depending on the specific laboratory and testing methods used. Additionally, certain populations, such as athletes or people living at high altitudes, may have naturally higher hematocrit levels due to increased red blood cell production.

Factors Influencing Hematocrit Levels

1. Age
2. Sex
3. Pregnancy status
4. Altitude
5. Hydration levels
6. Recent blood loss or transfusions
7. Certain medications

High Hematocrit: Causes, Symptoms, and Risks

Elevated hematocrit levels, also known as polycythemia, occur when the percentage of red blood cells in the blood exceeds normal ranges. This condition can be either primary (caused by increased red blood cell production) or secondary (resulting from other underlying factors).

Common Causes of High Hematocrit

• Polycythemia vera (a bone marrow disorder)
• Dehydration
• Chronic lung diseases
• Heart conditions causing low blood oxygen levels
• Smoking
• Living at high altitudes
• Certain medications or performance-enhancing drugs

Symptoms of high hematocrit can include headaches, dizziness, fatigue, and itchy skin. In severe cases, elevated hematocrit levels increase the risk of blood clots, which can lead to serious complications such as stroke or heart attack.

Low Hematocrit: Understanding the Implications

Low hematocrit levels, often associated with anemia, indicate a decrease in the proportion of red blood cells in the blood. This condition can result from various factors and may require medical intervention.

Potential Causes of Low Hematocrit

• Iron deficiency anemia
• Vitamin B12 or folate deficiency
• Chronic diseases (e.g., kidney disease, cancer)
• Blood loss (acute or chronic)
• Bone marrow disorders
• Certain medications
• Pregnancy

Symptoms of low hematocrit can include fatigue, weakness, shortness of breath, and pale skin. Severe anemia may lead to complications such as heart problems or developmental issues in children.

Diagnostic Approaches for Abnormal Hematocrit Levels

When hematocrit levels fall outside the normal range, healthcare providers typically conduct further tests to determine the underlying cause and develop an appropriate treatment plan.

Common Diagnostic Procedures

1. Complete blood count (CBC) with differential
2. Peripheral blood smear
3. Iron studies (serum iron, ferritin, total iron-binding capacity)
4. Vitamin B12 and folate levels
5. Erythropoietin (EPO) levels
6. Bone marrow biopsy (in some cases)
7. Genetic testing for inherited blood disorders

The specific tests ordered will depend on the patient’s symptoms, medical history, and initial blood work results. A thorough diagnostic approach is crucial for developing an effective treatment strategy.

Treatment Options for High Hematocrit

Managing high hematocrit levels often involves addressing the underlying cause while also taking steps to reduce the risk of complications associated with blood hyperviscosity.

Common Treatment Approaches

• Phlebotomy (therapeutic blood removal)
• Hydration therapy
• Low-dose aspirin to reduce blood clot risk
• Medications to suppress red blood cell production (e.g., hydroxyurea)
• Lifestyle modifications (e.g., smoking cessation, altitude changes)
• Treatment of underlying conditions (e.g., lung or heart diseases)

For patients with polycythemia vera, a combination of phlebotomy and medications is often recommended to maintain hematocrit levels below 45%. Regular monitoring and follow-up care are essential for managing this chronic condition effectively.

Addressing Low Hematocrit: Treatment Strategies

Treatment for low hematocrit focuses on identifying and addressing the root cause while also improving the patient’s red blood cell count and overall health.

Treatment Options for Low Hematocrit

• Iron supplementation (for iron deficiency anemia)
• Vitamin B12 injections or supplements
• Folic acid supplementation
• Erythropoiesis-stimulating agents (ESAs)
• Blood transfusions (in severe cases)
• Treatment of underlying chronic diseases
• Dietary changes and nutritional counseling

The specific treatment plan will depend on the underlying cause of the low hematocrit and the severity of the anemia. In some cases, a combination of therapies may be necessary to achieve optimal results.

Long-term Management and Monitoring of Hematocrit Levels

For patients with chronic conditions affecting their hematocrit levels, ongoing management and regular monitoring are crucial for maintaining health and preventing complications.

Key Components of Long-term Management

1. Regular blood tests to monitor hematocrit and other blood parameters
2. Adjusting medications or treatments as needed
3. Lifestyle modifications to support overall health
4. Management of underlying chronic conditions
5. Vigilance for signs of complications or disease progression
6. Patient education about their condition and self-monitoring techniques

Effective long-term management often requires a collaborative approach between patients and their healthcare providers, with open communication and shared decision-making playing crucial roles in achieving optimal outcomes.

Hematocrit in Special Populations: Considerations and Challenges

Certain populations require special consideration when it comes to interpreting and managing hematocrit levels. These groups may have unique physiological factors or health concerns that influence their normal hematocrit ranges and treatment approaches.

Pregnant Women

Pregnancy causes significant changes in blood volume and composition. Hematocrit levels typically decrease during pregnancy due to the increase in plasma volume outpacing the increase in red blood cell production. This physiological anemia is normal and doesn’t usually require treatment. However, monitoring is important to ensure levels don’t drop too low, which could indicate true anemia requiring intervention.

Athletes

Endurance athletes often have higher than average hematocrit levels due to the body’s adaptation to increased oxygen demands. This “sports anemia” is generally not a cause for concern. However, it’s important to differentiate between natural adaptations and potential use of performance-enhancing drugs that can dangerously elevate hematocrit levels.

Elderly Patients

Older adults may have lower hematocrit levels due to various factors, including chronic diseases, nutritional deficiencies, and decreased bone marrow function. Interpreting hematocrit results in this population requires careful consideration of overall health status and potential underlying conditions.

Neonates and Infants

Newborns typically have higher hematocrit levels at birth, which gradually decrease over the first few months of life. Premature infants may require special monitoring and management of hematocrit levels due to their increased risk of anemia.

The Role of Nutrition in Maintaining Healthy Hematocrit Levels

Proper nutrition plays a crucial role in supporting healthy red blood cell production and maintaining optimal hematocrit levels. Understanding the key nutrients involved and incorporating them into a balanced diet can help prevent deficiencies and support overall blood health.

Essential Nutrients for Healthy Hematocrit

• Iron: Crucial for hemoglobin production
• Vitamin B12: Necessary for red blood cell maturation
• Folate: Important for DNA synthesis in red blood cells
• Vitamin C: Enhances iron absorption
• Copper: Supports iron metabolism
• Vitamin A: Aids in mobilizing iron from storage

Incorporating a variety of nutrient-rich foods into one’s diet can help ensure adequate intake of these essential components. For those with specific deficiencies or increased needs, targeted supplementation under medical supervision may be recommended.

Dietary Sources of Key Nutrients

1. Iron: Red meat, poultry, fish, beans, leafy greens
2. Vitamin B12: Animal products, fortified cereals, nutritional yeast
3. Folate: Leafy greens, legumes, fortified grains
4. Vitamin C: Citrus fruits, berries, bell peppers, broccoli
5. Copper: Nuts, seeds, whole grains, shellfish
6. Vitamin A: Orange and yellow fruits and vegetables, leafy greens

For individuals with specific dietary restrictions or increased nutritional needs, consulting with a registered dietitian can help ensure optimal nutrient intake to support healthy hematocrit levels.

Emerging Research and Future Directions in Hematocrit Management

The field of hematology continues to evolve, with ongoing research aimed at improving our understanding of red blood cell disorders and developing more effective treatments for abnormal hematocrit levels.

Promising Areas of Research

• Gene therapy for inherited blood disorders
• Novel targeted therapies for polycythemia vera
• Improved erythropoiesis-stimulating agents with fewer side effects
• Advanced imaging techniques for assessing blood viscosity
• Personalized medicine approaches based on genetic profiling

As research progresses, it’s likely that we’ll see more tailored treatment approaches and improved outcomes for patients with hematocrit-related disorders. Staying informed about these advancements can help healthcare providers and patients make more informed decisions about management strategies.

Potential Future Developments

1. Artificial blood substitutes to manage severe anemia
2. Nanotechnology-based treatments for blood disorders
3. Advanced point-of-care testing for rapid hematocrit assessment
4. Machine learning algorithms for predicting treatment responses
5. Novel drug delivery systems for more efficient therapies

While many of these developments are still in early stages, they highlight the dynamic nature of hematology research and the potential for significant advancements in hematocrit management in the coming years.

The Importance of Patient Education in Hematocrit Management

Effective management of hematocrit levels often requires active patient involvement and understanding. Educating patients about their condition, treatment options, and the importance of adherence to management plans can significantly improve outcomes and quality of life.

Key Components of Patient Education

• Understanding normal hematocrit ranges and individual target levels
• Recognizing signs and symptoms of abnormal hematocrit levels
• Importance of regular monitoring and follow-up appointments
• Proper use of prescribed medications or supplements
• Lifestyle modifications to support overall health
• Potential complications and when to seek medical attention

Healthcare providers play a crucial role in ensuring patients have the knowledge and resources they need to actively participate in their care. This may involve providing written materials, recommending reliable online resources, or offering educational sessions to patients and their families.

Benefits of Patient Education

1. Improved treatment adherence
2. Better self-monitoring and early detection of issues
3. Reduced anxiety and improved quality of life
4. More informed decision-making about treatment options
5. Enhanced communication between patients and healthcare providers

By empowering patients with knowledge about their hematocrit levels and overall blood health, healthcare providers can foster a collaborative approach to management that leads to better long-term outcomes.

Polycythemia – StatPearls – NCBI Bookshelf

Continuing Education Activity

Polycythemia, also called erythrocytosis, refers to increased red blood cell mass, noted on laboratory evaluation as increased hemoglobin and hematocrit levels. Polycythemia vera is a subtype of polycythemia and can be associated with the overproduction of more than just the erythrocytic lineage. The clinical significance of erythrocytosis, due to any cause, is related to the associated risk of thrombotic events due to hyperviscosity of blood. Additionally, in cases of polycythemia vera, there is potential for progression to leukemia. This activity reviews the evaluation, treatment, and potential complications of polycythemia vera and highlights the role of the interprofessional team in identifying and treating this condition.

Objectives:

• Describe the typical presenting features of polycythemia.

• Outline the management of polycythemia.

• Review the potential complications of polycythemia.

• Use interprofessional team strategies to improve care coordination and communication to improve the evaluation and management of patients with polycythemia and optimize outcomes.

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Introduction

Polycythemia, or erythrocytosis, refers to an increase in the absolute red blood cell (RBC) mass in the body. In practice, this is reflected by an increase in hemoglobin levels, or hematocrit, over what is considered physiologic for the particular age and gender.

The standard RBC mass does not usually exceed 36 ml/kg in males and 32 ml/kg in females. The reference ranges for normal hemoglobin levels and hematocrit vary depending on altitude, ethnicity, and country.[1] However, as a frame of reference, the hemoglobin and hematocrit of a healthy adult male are 16 g/dL +/- 2 gm/dl and 47% +/- 6%, respectively. The hemoglobin and hematocrit of a menstruating adult female are usually 13 g/dL +/- 2 gm/dl and 40% +/- 6%, respectively.  Polycythemia in newborns is defined as a central venous hematocrit over 65% or a hemoglobin value above 22 g/dL.[2]

Polycythemia vera is a sub-type of polycythemia. Often referred to colloquially as simply “polycythemia,” it is an acquired, Philadelphia-chromosome negative[3], myeloproliferative disorder. This condition can be associated with the overproduction of all three cell lines but with a notable predilection towards red blood cells.

The clinical significance of erythrocytosis, due to any cause, lies in the associated risk of thrombotic events due to hyperviscosity of blood. Additionally, the potential for progression to leukemia in cases of polycythemia vera also warrants additional management strategies to be implemented.

Etiology

Classification

Spurious Polycythemia

This occurs due to volume contraction rather than an increase in true RBC mass.

Causes include

• Severe dehydration due to isolated fluid loss: potentially seen in diarrhea and severe vomiting

• Gaisbock syndrome: Usually seen amongst obese, hypertensive males. Smoking, excessive alcohol, and use of diuretics are contributory.[4]

True Polycythemia

Further stratified based on serum erythropoietin (EPO) levels as follows:

Low serum EPO levels (Primary polycythemia)

High serum EPO levels (Secondary polycythemia)

• High altitude

• Respiratory disorders: Chronic obstructive pulmonary disease (COPD), Pickwickian syndrome, uncontrolled asthma

• Cyanotic heart diseases with right-to-left shunts

• Renal disorders: Renal cysts, kidney cancer, renal artery stenosis, Bartter syndrome, focal sclerosing glomerulonephritis

• Elevated carboxyhemoglobin: Usually seen in smokers, people working on cars in closed spaces, or people working in boiler rooms

• Hemoglobinopathies: High-affinity hemoglobins such as Hb Yakima, methemoglobinemia

• EPO-secreting tumors: sources include hepatomas, uterine leiomyomas, and cerebellar hemangiomas

• Iatrogenic causes: Including erythropoietin analog administration, anabolic steroids, and testosterone replacement therapy

Neonatal Polycythemia

• The increase in hematocrit is a normal compensatory mechanism in infants due to the relative tissue-level hypoxia in the intrauterine environment. It is exacerbated by the high affinity of fetal hemoglobin for oxygen.

Epidemiology

The prevalence of polycythemia vera has been estimated to be approximately 22 cases per 100,000 population[5]. It is believed to occur more frequently among Jewish patients of Eastern European descent than other Europeans and Asians. Polycythemia vera shows a male preponderance in all races and ethnicities, with a male-to-female ratio of approximately 2 to 1. The median age of presentation of PV is 60 years, with patients seldom seen before the age of 40. Polycythemia due to hemoglobinopathies and congenital cyanotic heart diseases is likely to be detected in significantly younger patients.

Pathophysiology

The pathophysiology would vary, depending on the cause in consideration.

High EPO Levels

Cellular hypoxia can occur due to any cause that triggers the release of erythropoietin from the renal peritubular lining capillary cells. A small amount of EPO is produced by the liver as well. EPO, in turn, acts on erythroid progenitor cells and stimulates erythropoiesis. 

Low EPO Levels

The primary defect in nearly 95% of cases of polycythemia vera is an acquired mutation in exon 14 of the tyrosine kinase JAK2 (V617F). Mutations have also been described in exon 12 of JAK2. These mutations result in a loss of the auto-inhibitory pseudo-kinase domain of JAK2, resulting in its constitutive activation. This constitutive activation results in both hypersensitivity to EPO and EPO-independent erythroid colony formation.[6]

Histopathology

Bone marrow examination is not routinely employed. Its utility largely remains restricted to cases where the clinical suspicion of polycythemia vera is high, despite the absence of a JAK2 (V617F) mutation, or if facilities to test for the mutation are unavailable. Classical findings, when coexistent with other suggestive hematologic parameters, help support a diagnosis of polycythemia vera. [7]

Strongly suggestive findings include a hypercellular marrow with erythroid hyperplasia and subtle megakaryocytic atypia.[8] Tri-lineage hyperproliferation is also an expected feature.

History and Physical

History

• Common presenting symptoms, usually non-specific, include fatigue, headache, dizziness, transient blurry vision, amaurosis fugax, and other symptoms suggestive of transient ischemic attacks (TIAs).

• Infrequently, patients may complain of pruritus after a warm water shower, particularly over the back.

• A history of epistaxis, gastrointestinal (GI) bleeding, or easy bruising may be forthcoming.

• Peptic ulcer disease commonly coexists, and patients may present with non-specific abdominal pain. Left hypochondrial pain and early satiety should raise the suspicion of splenomegaly.

• Rarely, patients may present with a history of unexplained thrombotic complications, such as Budd-Chiari syndrome or digital infarcts.

• It is vital to try and elicit etiology-specific history, such as a history of smoking, an extended stay at high altitudes, and congenital cardiac disease, among others. Significant family history may be noted in patients with hemoglobinopathies.

Physical Examination

• Abnormal facial ruddiness may be prominent.

• Cyanosis and clubbing, along with the presence of a murmur on auscultation, provide strong evidence favoring a congenital cyanotic heart disease.

• Nicotine staining of the nails and teeth provides presumptive evidence of smoking, even in a non-forthcoming patient.

• Morbid obesity could raise the possibility of Pickwickian syndrome, whereas a barrel chest could suggest obstructive lung disease.

• Examining the abdomen may lead to finding a palpable spleen or eliciting the bruit of renal arterial stenosis in a thin-built individual.

Evaluation

An evaluation must proceed sequentially. Due to the broad array of potential causes, it is vital to consider the appropriate investigation in that specific clinical context. However, the following may provide a frame of reference:

Hemogram

Based on the WHO 2017 criteria, hematocrit levels above 49% in males and 48% in females at sea level are to be considered suggestive of polycythemia vera. In cases of polycythemia vera, there could be a concurrent increase in platelet and leukocyte counts as well. The leucocyte count is usually between 10,000 to 20,000/microliter and may show eosinophilia and basophilia. Platelet counts may rarely exceed 1,000,000/microliter.

Radioisotope Studies

Radioisotope studies using chromium-labeled autologous RBC transfusions accurately determine the true RBC mass and conclusively exclude spurious polycythemia.

Serum EPO Levels

The presence of either high or low EPO levels directs the further plan of evaluation.

• Low EPO Levels

Low EPO levels indicate primary polycythemia. Subsequent evaluation should be targeted toward the detection of polycythemia vera.

JAK2 mutation studies are virtually diagnostic for polycythemia vera (95% cases). Mutations may occur either in exon 14 (more commonly) or in exon 12.

• High EPO Levels

High EPO levels indicate secondary polycythemia. Subsequent evaluation should be aimed at determining the cause. This should include, but not be limited to, the following:

• Measurement of arterial oxygen saturation levels using a pulse-oximeter: low levels would likely indicate a pulmonary or cardiac cause.

• Normal saturation levels could require further evaluation, such as:

  • The use of a co-oximeter to rule out methemoglobinemia

  • Measurement of carboxyhemoglobin levels for smokers

  • Measurement of the P50 of Hb to detect high-affinity hemoglobinopathies

  • Relevant investigations to detect a possible EPO-secreting tumor

Serum Ferritin, Vitamin B12, and Folate Levels

Low serum ferritin and low folate levels have been associated more with primary polycythemia. [4] Raised vitamin B12 levels, often striking, may be observed. This occurs due to increased transcobalamin III secretion by leukocytes. 

Assessment of Renal Function

Renal function abnormalities indicate a higher likelihood of secondary polycythemia. Uric acid levels are often raised due to increased cell proliferation and subsequent turnover.

Assessment of Hepatic Status

Liver cirrhosis and inflammatory liver disease have been associated with secondary polycythemia and increased RBC proliferation.[4]

Ultrasound

An ultrasound and Doppler study of the abdomen would help identify a secondary cause.

In cases of suspected secondary polycythemia, the utility of additional investigations such as a chest radiograph, lung function tests, sleep studies, and an echocardiograph are to be considered as appropriate.

Treatment / Management

The treatment of secondary polycythemia is directed at correcting the cause.

For polycythemia vera, available treatment modalities include:

Phlebotomy

Phlebotomy was established as the backbone of therapy, primarily based on the trial conducted by the Polycythemia Vera Study Group (PVSG). The study found that, compared to chlorambucil or radioactive phosphorous treatment, treatment with phlebotomy alone was associated with longer median survival.[9]

The rationale behind repeated phlebotomies was that cytoreduction would reduce hyperviscosity. Additionally, it would induce a state of iron deficiency that would help retard red-cell proliferation.

In practice, weekly sessions are conducted, during which approximately 500 mL of blood is removed, provided the hemodynamic status permits this.

This is continued weekly until a target hematocrit of under 45% is obtained. This target was determined based on the findings of the CYTO-PV trial conducted in Italy. Investigators observed significantly lower rates of cardiovascular deaths and major thrombotic episodes in patients kept under this threshold.[10]

For secondary polycythemias, phlebotomy is usually reserved for the following conditions:[11]

• Chronic lung diseases

• Cyanotic heart diseases

• Post-renal transplant patients with hypertension and erythrocytosis, not responding to optimal doses of angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs)

Hydroxyurea

Hydroxyurea is usually considered second-line therapy. Evidence of benefit came from, among others, a study by the Polycythemia Vera Study Group (PVSG) that showed lower rates of thrombosis compared to a historical cohort treated with phlebotomy alone.[12] Despite theoretical concerns, studies have not found a significant association between the use of hydroxyurea and an increased risk of leukemic transformation.[13] Indications for use include:

• Poor venous access

• High phlebotomy requirement

• When phlebotomy is not possible due to logistic reasons

• Severe thrombocytosis

• Intractable pruritus

The standard daily doses range from 500 to 1500 mg per day.

Doses are adjusted to target platelet counts below 500,000/mcL. However, it is necessary to adjust doses such that the absolute neutrophil count remains above 2000/microliters.

Ruxolitinib

The JAK2 inhibitor ruxolitinib is used when patients are intolerant or unresponsive to hydroxyurea.

Evidence supporting the use of Ruxolitinib in myeloproliferative disorders came from the COMFORT trials. The COMFORT-I study compared the efficacy of Ruxolitinib with placebo therapy, whereas COMFORT-II compared it with the “best available therapy.” Both trials showed a significant reduction in splenomegaly, improvement in symptoms, and better survival.[14][13][14]

However, despite this enhanced benefit, the use of ruxolitinib was associated with increased risks of anemia, often dose-limiting, and thrombocytopenia.

The standard recommended dose for polycythemia vera is 10 mg twice a day.

Dose reduction is required if hemoglobin drops to below 12 gm/dl.

A fall in hemoglobin to below 8 gm/dl indicates that dosing is to be temporarily interrupted.

Low-Dose Aspirin

The original PVSG trial showed that, despite greater longevity, patients treated with phlebotomy alone were at a greater risk of developing thrombosis during the first three years of therapy. This seemed to suggest a potential benefit to concurrently using antiplatelet or anticoagulant agents. Initial trials using higher doses of aspirin or dipyridamole showed unsatisfactory gastrointestinal hemorrhage. However, subsequent studies found that lower doses of aspirin could be safely used.[15]

Currently, aspirin is indicated when there is inadequate control of microvascular symptoms after achieving the target hematocrit or in the presence of other cardiovascular risk factors.

Aspirin, when indicated, is recommended to be used at low doses, ranging from 40 to 100 mg daily.

Hypouricemic Agents

Agents such as allopurinol and febuxostat may be required in cases with significant hyperuricemia. Recent studies indicate that, between them, allopurinol may be a safer alternative with respect to all-cause and cardiovascular mortality.[16]

Management of Pruritus

Depending on the severity of pruritus and the clinical response to therapy, therapeutic modalities available for symptomatic relief include antihistamines[17] and selective serotonin reuptake inhibitors (SSRIs). [18]

Management of Polycythemia Vera in Pregnancy

The standard therapeutic measures of phlebotomy and low-dose aspirin are appropriate in most cases. Certain high-risk women may require the addition of pegylated interferon (IFN)-alpha.[19]

Management of Neonatal Polycythemia

Most patients do not need treatment. Exchange transfusion is occasionally required due to hyperviscosity.

Differential Diagnosis

• Primary myelofibrosis

• Chronic myeloid leukemia

• Essential thrombocythemia

• EPO receptor mutations

Prognosis

Studies estimate the median survival in cases diagnosed with polycythemia vera to be approximately 14.1 years.[13]

Factors that were found to correlate with better prognosis included:

Factors associated with worse outcomes included:

• Higher leucocyte counts

• Venous thrombosis

• Leukoerythroblastic blood smear

Complications

Secondary polycythemia is associated primarily with complications arising from hyperviscosity. Polycythemia vera is associated with complications associated with an increased risk of thrombosis and progression to malignant conditions.

Commonly encountered complications include:

1. Bleeding: Recurrent epistaxis or GI bleeding is often seen, which may lead to iron deficiency anemia, potentially confounding clinical findings, including bone marrow appearance.

2. Thrombosis: Due to hyperviscosity, there is a preponderance of both arterial and venous thrombosis. Manifestations of arterial thrombosis include digital infarcts, and cerebral ischemic infarcts, particularly in watershed territories. Venous thrombosis, such as Budd-Chiari syndrome, is also seen.

Progression to leukemia, particularly acute myeloid leukemia (AML), is seen in approximately 5% of cases and is often refractory to treatment. Studies have implicated the use of chlorambucil, pipobroman, or radioactive phosphorous as factors that increase the likelihood of progression.

Consultations

 A hematologist consultation should be sought in all cases of suspected primary polycythemia.

Deterrence and Patient Education

Patients must be encouraged to stop smoking. Genetic counseling must be offered to the families of those with hemoglobinopathies. Patients with polycythemia vera must be discouraged from donating blood. Because this is a myeloproliferative disorder, blood from donors with polycythemia vera is not considered appropriate for donation in most countries.

Enhancing Healthcare Team Outcomes

Polycythemia can affect every organ in the body, and the symptoms are primarily related to impaired oxygen delivery and blood hyperviscosity. The condition is primarily managed by the hematologist, but managing complications requires an interprofessional team comprised of clinicians, specialists, nursing staff, pharmacists, and phlebotomists. Patients need to be educated by clinicians about the potential complications and when to seek medical assistance. Pharmacists will help manage medication regimens, verify dosing, check for interactions, and offer patients medication counseling. Nurses will assist in patient evaluation, counsel patients about their condition, answer patient questions, and serve as coordinators for the activities of the various disciplines covering the case. The interprofessional model requires open communication among all care team members, including accurate record-keeping. This approach will result in improved patient outcomes. [Level 5]

While survival has improved over the past three decades, the aim is also to maintain quality of life. Apart from thrombotic complications, there is also an increased risk of bleeding as well as a risk of infections. Finally, patients should be made aware that they need lifelong follow-up as there is a risk of progression to acute leukemia or myeloproliferative syndrome. The nursing staff should coordinate and monitor close follow-up and assist in educating the patient and family to ensure regular care is obtained. [21] [Level 1]

Review Questions

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References

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Marchioli R, Finazzi G, Specchia G, Masciulli A, Mennitto MR, Barbui T. The CYTO-PV: A Large-Scale Trial Testing the Intensity of CYTOreductive Therapy to Prevent Cardiovascular Events in Patients with Polycythemia Vera. Thrombosis. 2011;2011:794240. [PMC free article: PMC3200258] [PubMed: 22084668]

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Fruchtman SM, Mack K, Kaplan ME, Peterson P, Berk PD, Wasserman LR. From efficacy to safety: a Polycythemia Vera Study group report on hydroxyurea in patients with polycythemia vera. Semin Hematol. 1997 Jan;34(1):17-23. [PubMed: 9025158]

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Disclosure: Ashwin Pillai declares no relevant financial relationships with ineligible companies.

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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.

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.