Polycythemia is an increased volume of red blood cells. The hematocrit is elevated by more than 55% in males or more than 50% in females. Polycythemia is classified as either primary or secondary.
Secondary Polycythemia
Secondary polycythemia is caused by excessive production of erythropoietin. This may occur in response to a reduced amount of oxygen (which acts as a hypoxic stimulus), as in cases of heavy cigarette smoking, chronic obstructive pulmonary disease (COPD), cyanotic heart disease, or nonpathologic conditions such as living at a high altitude. It can also result from certain hemoglobinopathies (e.g., hemoglobin Chesapeake), in which the hemoglobin has an abnormally high affinity for oxygen, or it can occur from a neoplasm, such as renal cell carcinoma. Secondary polycythemia can also occur from neoplasms (e.g., renal cell carcinoma) that stimulate erythropoietin production.
Polycythemia Vera (Primary)
Polycythemia vera, or primary polycythemia, is a proliferative disorder of the myeloid stem cells. The bone marrow is hypercellular, and the erythrocyte, leukocyte, and platelet counts in the peripheral blood are elevated. Diagnosis is based on an elevated erythrocyte mass, a normal oxygen saturation level, and often an enlarged spleen. The erythropoietin level may not be as low as would be expected with an elevated hematocrit.
Outline
- Ruddy complexion and splenomegaly
- Increased blood volume leading to headache, dizziness, tinnitus, fatigue, paresthesias, and blurred vision
- Increased blood viscosity leading to angina, claudication, dyspnea, and thrombophlebitis
- Elevated blood pressure and uric acid levels
- Erythromelalgia (a burning sensation in the fingers and toes)
Quality and Safety Nursing Alert
| Patients with neutropenia often do not exhibit classic signs of infection. Fever is the most common indicator of infection, yet it is not always present, particularly if the patient is taking corticosteroid agents. |
Management of secondary polycythemia involves treatment of the primary problem. If the cause cannot be corrected, phlebotomy may be necessary to reduce hypervolemia and hyperviscosity.
The objective of management is to reduce the high red blood cell mass.
- Phlebotomy is performed repeatedly to keep the hemoglobin within normal range; iron supplements are avoided.
- Chemotherapeutic agents are used to suppress marrow function (may increase risk for leukemia).
- Anagrelide (Agrylin) may be used to inhibit platelet aggregation and control the thrombocytosis related to polycythemia vera.
- Interferon-alpha-2b (IntronA) is the most effective treatment for managing the pruritus associated with polycythemia vera.
- Antihistamines may be given to control pruritus (not very effective).
- Allopurinol is used to prevent attacks of gout when the uric acid level is elevated.
- Assess risk factors for thrombotic complications and educate patient in ways to recognize signs and symptoms of thrombosis.
- Discourage sedentary behavior, crossing the legs, and wearing tight or restrictive clothing (particularly stockings); this will reduce the likelihood of deep vein thrombosis.
- Advise patient to avoid aspirin and medications containing aspirin (if patient has a history of bleeding).
- Advise patient to minimize alcohol intake and avoid iron (and vitamins containing iron).
- Suggest a cool or tepid bath for pruritus, along with cocoa butter-based lotions and bath products to relieve itching.
For more information, see Chapter 33 in Hinkle, J. L., & Cheever, K. H. (2018). Brunner and Suddarth's textbook of medical-surgical nursing (14th ed.). Philadelphia, PA: Lippincott Williams & Wilkins.