Polycythemia vera is a disease in which too many red blood cells are made in the bone marrow.

In polycythemia vera, the blood becomes thickened with too many red blood cells. The number of white blood cells and platelets may also increase. These extra blood cells may collect in the spleen and cause it to swell. The increased number of red blood cells, white blood cells, or platelets in the blood can cause bleeding problems and make clots form in blood vessels. This can increase the risk of stroke or heart attack. In patients who are older than 65 years or who have a history of blood clots, the risk of stroke or heart attack is higher. Patients also have an increased risk of acute myeloid leukemia or primary myelofibrosis.

In contrast to anemia, an elevated RBC count is called polycythemia and is detected in a patient’s elevated hematocrit. It can occur transiently in a person who is dehydrated; when water intake is inadequate or water losses are excessive, the plasma volume falls. As a result, the hematocrit rises. For reasons mentioned earlier, a mild form of polycythemia is chronic but normal in people living at high altitudes. Some elite athletes train at high elevations specifically to induce this phenomenon. Finally, a type of bone marrow disease called polycythemia vera (from the Greek vera = “true”) causes an excessive production of immature erythrocytes. Polycythemia vera can dangerously elevate the viscosity of blood, raising blood pressure and making it more difficult for the heart to pump blood throughout the body. It is a relatively rare disease that occurs more often in males than in females, and is more likely to be present in elderly patients those over 60 years of age.

Primary Polycythemia

Polycythemia vera (PV) also is known as primary polycythemia. A mutation, or change, in the body's JAK2 gene is the main cause of PV. The JAK2 gene makes a protein that helps the body produce blood cells.

What causes the change in the JAK2 gene isn't known. PV generally isn't inherited—that is, passed from parents to children through genes. However, in some families, the JAK2 gene may have a tendency to mutate. Other, unknown genetic factors also may play a role in causing PV.

Secondary Polycythemia

Another type of polycythemia, called secondary polycythemia, isn't related to the JAK2 gene. Long-term exposure to low oxygen levels causes secondary polycythemia.

A lack of oxygen over a long period can cause your body to make more of the hormone erythropoietin (EPO). High levels of EPO can prompt your body to make more red blood cells than normal. This leads to thicker blood, as seen in PV.

People who have severe heart or lung disease may develop secondary polycythemia. People who smoke, spend long hours at high altitudes, or are exposed to high levels of carbon monoxide where they work or live also are at risk.

For example, working in an underground parking garage or living in a home with a poorly vented fireplace or furnace can raise your risk for secondary polycythemia.

Rarely, tumors can make and release EPO, or certain blood problems can cause the body to make more EPO.

Sometimes doctors can cure secondary polycythemia—it depends on whether the underlying cause can be stopped, controlled, or cured.

This histology can be determined by positive histology (including peripheral blood) with or without genetics and/or immunophenotyping.

Definitive Diagnostic Methods

Bone marrow biopsy Clinical diagnosis Genetic testing

Genetics Data

BCR-ABL1 fusion absent Janus kinase-2, JAK2 JAK2 V617F Philadelphia (Ph) chromosome absent

Immunophenotyping

None

Symptoms of polycythemia vera include headaches and a feeling of fullness below the ribs on the left side.

Polycythemia vera often does not cause early signs or symptoms. It may be found during a routine blood test. Signs and symptoms may occur as the number of blood cells increases. Other conditions may cause the same signs and symptoms. Check with your doctor if you have any of the following:

• A feeling of pressure or fullness below the ribs on the left side.
• Headaches.
• Double vision or seeing dark or blind spots that come and go.
• Itching all over the body, especially after being in warm or hot water.
• Reddened face that looks like a blush or sunburn.
• Weakness.
• Dizziness.
• Weight loss for no known reason.

Polycythemia vera is a condition characterized by an increased number of red blood cells in the bloodstream (erythrocytosis). Affected people may also have excess white blood cells and platelets. Conditions where the body makes too many of these cells are known as myeloproliferative neoplasms. These extra cells cause the blood to be thicker than normal, increasing the risk for blood clots that can block blood flow in arteries and veins. If a blood clot occurs in the veins deep in the arms and the legs, it is known as deep vein thrombosis (DVT). A DVT can sometimes travel through the blood stream to the lungs, which can cause a pulmonary embolism and is very dangerous. A blood clot could also travel to the heart or brain, which leads to an increased risk for heart attack or stroke. Most cases of PV are not inherited and are acquired during a person's lifetime. PV occurs more frequently in men than it does in women. The condition has been associated with genetic changes in the JAK2 and TET2 genes. In rare cases, the risk for PV runs in families and may be inherited in an autosomal dominant manner.

Special blood tests are used to diagnose polycythemia vera.

In addition to a complete blood count, bone marrow aspiration and biopsy, and cytogenetic analysis, a serum erythropoietin test is used to diagnose polycythemia vera. In this test, a sample of blood is checked for the level of erythropoietin (a hormone that stimulates new red blood cells to be made). In polycythemia vera, the erythropoietin level would be lower than normal because the body does not need to make more red blood cells.

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.)

A hematologic condition marked by an abnormal increase in the number of RBCs in the body is called polycythemia . This condition can be primary (genetic) or secondary (caused by other diseases or conditions, such as chronic lung disease, kidney disease, cardiopulmonary shunts) (Haider & Anwar, 2023). Polycythemia increases the blood’s viscosity (thickness), resulting in complications including blood clots, cardiovascular issues, and reduced circulation. When caring for patients with polycythemia, the primary objectives are to identify its underlying causes, take appropriate diagnostic steps, and devise tailored management strategies to minimize potential risks while increasing overall well-being for patients.

Pathophysiology of Polycythemia

The pathophysiology of polycythemia can be divided into two major subcategories: primary and secondary. Primary polycythemia, or polycythemia vera , is a myeloproliferative disorder, which means it originates from the bone marrow (Pillai et al., 2023). A genetic mutation causes an abnormal response to the hormone EPO, an important hormone that stimulates RBC production from the kidneys, causing erythropoiesis (RBC production) to increase independently of the body’s natural regulatory mechanisms (Pillai et al., 2023). Overproduction of RBCs increases blood viscosity, impairing blood flow and increasing the risk for thrombosis, stroke, or myocardial infarction.

When EPO stimulation occurs as an adaptive reaction to other conditions, secondary polycythemia occurs. Recall that EPO ( erythropoietin ) is normally released by the kidneys as a response to low oxygen levels in blood. The abnormal release triggers the bone marrow to increase RBC production. This can lead to impaired blood flow, with potential complications including stroke or myocardial infarction. Conditions that can trigger secondary polycythemia include chronic hypoxia from respiratory or cardiovascular illnesses, congenital heart disease, and certain tumors such as renal cell carcinoma. Smoking and living at high elevation can also trigger excess RBC production.

Primary and secondary polycythemia both can result in complications arising from increased blood viscosity, making it imperative that its root causes be addressed to reduce any risk for thrombotic events. Treatment strategies may include phlebotomy to lower RBC counts, medication to address symptoms, and management of any secondary conditions underlying polycythemia. An interdisciplinarian team approach is key to optimize management and avoid possible complications related to polycythemia.

Clinical Manifestations

Clinical presentation of polycythemia varies from patient to patient. Symptoms may be nonspecific and may include fatigue, headache, and dizziness (Haider & Anwar, 2023). If large vessel occlusion occurs due to clumping of excess blood cells, symptoms will result in the occluded vessel. For example, if viscous blood clumps and creates a clot in a coronary artery, the patient may report chest pain, shortness of breath, fatigue, or nausea. If a clot develops in a brain artery, the patient may experience weakness (generalized or one sided), visual changes, or difficulty with speech.

Diagnostics and Laboratory Values

Diagnosing polycythemia requires performing various laboratory and diagnostic procedures that assess RBC counts as well as determine their source. Primary polycythemia often results in lower or normal EPO levels, while secondary polycythemia usually causes an increase. The following tests are used to help diagnose either type of polycythemia:

• A CBC count identifies Hb and Hct levels and compares them with the normal ranges. It also measures RBCs.
• Bone marrow aspiration and biopsy may be performed to evaluate the composition of blood cells as well as rule out other conditions that may exist in the bone marrow. Primary polycythemia affects bone marrow with increased cell volume due to increased RBC precursors.
• For accurate detection of primary polycythemia, genetic tests must look specifically for JAK2 mutations. An extensive diagnostic approach is key to distinguish primary from secondary polycythemia and provide appropriate management strategies.
• A simple pulse oximeter can measure the presence of hypoxia, which can stimulate RBC production and lead to secondary polycythemia.
• Chest x-rays and computed tomography (CT) scans can help identify lung diseases or tumors, which may be a cause of secondary polycythemia. Ultrasound or magnetic resonance imaging visual tests can also identify organ enlargement, such as of the spleen or liver, resulting from polycythemia.
• An arterial blood gas analysis can give information about blood pH and oxygenation. These data can help identify secondary causes of polycythemia, which may be causing the body to produce more RBCs.
• The cause of a thrombotic event can be identified by testing for clotting factors and blood components.

An extensive diagnostic approach is key to distinguishing primary from secondary polycythemia and providing appropriate management strategies. Patients suspected of polycythemia should undergo extensive evaluation by health-care providers.

Nursing Care of the Patient with Polycythemia

Nurses play an invaluable role in recognizing and interpreting signs in patients experiencing polycythemia. Through diagnostic studies, the nurse can recognize the overproduction of RBCs. Nursing actions include monitoring vital signs and clinical manifestations, completing a physical exam, and administering ordered treatments.

Recognizing and Analyzing Cues

By completing vital signs and a thorough head-to-toe assessment, nurses can recognize cues from each body system suggesting the existence of polycythemia (Table 16.3). A subjective assessment may include the patient stating feelings of fatigue, early satiety (feeling full), abdominal pain, inactivity, problems with concentration, night sweats, pruritus, bone pain, weight loss, and fever. Elevations in Hb, Hct, and EPO levels are particularly important when identifying polycythemia. Additional cues may be obtained from a thorough patient history, which should include questions about the patient’s history of smoking and altitude exposure.

Prioritizing Hypotheses, Generating Solutions, and Taking Action

Acute management of polycythemia centers around treating the cause, if possible; preventing thrombotic events due to the overproduction of RBCs; and symptom improvement. Dependent on the degree of symptoms, nursing interventions are tailored to the patient’s presentation (Brennan-Cook, 2020).

Ultimately, nurses assist patients with symptom control and reduction of thrombotic risk (Lu & Chang, 2023). Education is important. For example, the patient might be taught to slowly increase their activity level in alignment with their fatigue. If night sweats are a sign, nurses can educate patients to identify triggers (e.g., alcohol, spicy food, caffeine) and to adjust their intake accordingly. For early satiety, nurses can help patients plan a diet that is heart healthy and high in protein, whole grains, fruits, and vegetables. For severe pruritus, nonpharmacological remedies such as cool showers and skin moisturizers are recommended. Patients with brain fog or difficulty concentrating may require pharmacological therapy, including additional education on the purposes of these medications. Given the propensity for infection, identification of fevers that deviate from target temperature parameters and a comprehensive workup may be indicated (Brennan-Cook, 2020).

Evaluation of Nursing Care for the Patient with Polycythemia

Evaluation of nursing care for polycythemia centers around symptom management and tailoring interventions and care plans specifically to address each patient’s unique needs. It is important to perform regular assessments to evaluate how interventions affect symptom improvement.

Evaluating Outcomes

A continuous evaluation process is crucial to improving care delivery, avoiding complications, and supporting overall health and well-being for each patient. Stabilization of an acute exacerbation and/or avoiding a thrombotic event are ideal outcomes, but there are specific outcomes nurses may identify (Pillai et al., 2023), including:

• A reduction of self-reported physical symptoms and objective signs help the nurse assess for changes or improvements, which can dictate next steps.
• The stabilization or normalization of RBCs, Hb, and Hct, and comparing the current results with previous results.
• The patient can articulate importance of compliance with pharmacological therapy, and verbalizing signs and symptoms of a thrombotic event.
• The patient can report reduced anxiety and depression and identify healthy coping mechanisms. Evaluating the patient’s social support system can also help identify what resources will be needed.
• The patient maintains target parameters for oxygen saturation, heart rate, and blood pressure.

Medical Therapies and Related Care

The goal of medical management of polycythemia is to lower RBC counts, prevent complications such as thrombosis, and improve overall symptoms. The following are major therapies for patients with polycythemia:

• A therapeutic phlebotomy is the removal of excess RBCs by reducing overall blood volume. If the patient has no genetic concerns or other comorbidities, the removed blood may be donated to a blood bank or service. The frequency and quantity of each reduction is determined by the Hb and Hct levels (Pillai et al., 2023).
• Management of cardiovascular risk factors includes management of hypertension and anticoagulation. Maintaining blood pressure at an ideal level is critical for minimizing cardiovascular events, and cholesterol management helps mitigate cardiovascular risks (Pillai et al., 2023).
• Medications such as ruxolitinib, an immune modulator, specifically target the abnormal JAK2-signaling pathway associated with polycythemia vera. Hydroxyurea is a myelosuppressive medication to decrease RBC production; interferon-α may also be used. Low-dose aspirin therapy helps decrease the risk of thrombosis by inhibiting platelet aggregation (Pillai et al., 2023).
• Regular monitoring and assessment via blood tests, including CBC counts, are used to track Hct levels and adjust treatment accordingly. Imaging studies may also be performed periodically to measure liver and spleen sizes as well as assess for potential complications (Pillai et al., 2023).
• Smoking cessation is another important strategy for patients with polycythemia because nicotine can exacerbate polycythemia’s complications significantly. Smoking cessation should be pursued immediately to decrease these effects (Pillai et al., 2023).

Treatment decisions should take into consideration factors such as a patient’s age, overall health status, and risk factors, as well as their response to previous interventions. Individualized treatment plans for patients with polycythemia must be created in conjunction with hematologists or health-care providers specializing in blood disorders. Their ongoing monitoring and adjustments are integral to managing this condition effectively and avoiding potential complications.