polycythemia (redirected from inherited polycythemia)

polycythemia /poly·cy·the·mia/ (-si-thēm´e-ah) an increase in the total cell mass of the blood.

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absolute polycythemia  an increase in red cell mass caused by increased erythropoiesis, which may occur as a compensatory physiologic response to tissue hypoxia or as the principal manifestation of polycythemia vera.

hypertonic polycythemia  stress p.

relative polycythemia  a decrease in plasma volume without change in red blood cell mass so that the erythrocytes become more concentrated (elevated hematocrit), which may be an acute transient or a chronic condition.

polycythemia ru´bra  p. vera.

secondary polycythemia  any absolute increase in the total red cell mass other than polycythemia vera, occurring as a physiologic response to tissue hypoxia.

stress polycythemia  chronic relative polycythemia usually affecting white, middle-aged, mildly obese males who are active, anxiety-prone, and hypertensive.

polycythemia ve´ra  a myeloproliferative disorder of unknown etiology, characterized by abnormal proliferation of all hematopoietic bone marrow elements and an absolute increase in red cell mass and total blood volume, associated frequently with splenomegaly, leukocytosis, and thrombocythemia.

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pol·y·cy·the·mi·a (pl-s-thm-)

n.

A condition characterized by an abnormal increase in the number of red blood cells in the blood. Also called erythrocythemia, hypercythemia, hypererythrocythemia, hyperglobulia.

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Polycythemia

A condition characterized by an overabundance of red blood cells.

Mentioned in: Hypercoagulation Disorders

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polycythemia

[pol′ēsīthē′mē·ə]

Etymology: Gk, polys + kytos, cell, haima, blood

an increase in the number of erythrocytes in the blood that may be primary or secondary to pulmonary disease, heart disease, or prolonged exposure to high altitudes or may be idiopathic. Also called Osler's disease, polycythemia vera. Compare hypoplastic anemia, leukemia. See also altitude sickness, erythrocytosis.

observations Clinical manifestations for primary polycythemia include weakness and fatigue; a feeling of fullness in the head, with headache, lightheadedness, and dizziness; visual disturbances (scotoma, double or blurred vision); dyspnea; nosebleeds; night sweats; and epigastric and joint pain. Later signs include pruritus, clubbing of digits, a reddened face with engorged retinal veins, and hepatosplenomegaly. Secondary polycythemia may display the previously mentioned manifestations plus hypoxemia in the absence of hepatosplenomegaly and hypertension. Lab results in primary polycythemia include elevated RBC counts; elevated WBC count with basophilia; elevated Hgb levels; thrombocytosis and platelet dysfunction; elevated alkaline phosphatase, uric acid, and conalbumin levels; elevated serum vitamin B₁₂; and elevated histamine levels with low serum erythropoietin levels. Bone marrow aspiration shows panmyelosis. Laboratory tests in secondary polycythemia include elevated erythrocytes, elevated Hct and Hgb, elevated mean corpuscular volume, absence of leukocytosis and thrombocytosis, and erythroid hyperplasia of bone marrow. Thrombosis, cerebrovascular insult, peptic ulcers, myeloid metaplasia, leukemia, and hemorrhage are common complications in primary polycythemia and result in the death of about 50% of untreated individuals within 18 months of the appearance of symptoms. The median survival rate in treated individuals is 7 to 15 years. Hemorrhage is the most common complication of secondary polycythemia.

interventions Management of secondary polycythemia is directed at treating the underlying causes. The treatment for primary polycythemia is directed at reducing blood volume and viscosity and inhibiting bone marrow activity. The treatment mainstay is serial phlebotomy and is used to reduce RBC mass. Hydration therapy is used to reduce blood viscosity. Chemotherapeutic agents may be used to induce myelosuppression. Adjunctive therapy includes allopurinol to treat hyperuricemia, antihistamines to reduce pruritus, analgesics for joint pain, and antacids for gastric hyperacidity. A splenectomy may be indicated to treat resistant splenomegaly.

nursing considerations Nursing during the acute phase includes careful monitoring of intake and output during hydration therapy and phlebotomy to avoid over- or under-hydration. Comfort measures are instituted to relieve joint pain, itching, and heartburn. Passive and active range of motion and ambulation are used to promote circulation and prevent thrombus formation. If chemotherapeutic agents are used, education is needed about effects and side effects. Education is also important, and stress is placed on the chronic nature of disease, the need for long-term phlebotomy treatment, and the impending complications that will occur if the disease is left untreated.

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polycythemia [pol″e-si-the´me-ah]

an increase in the total red blood cell mass of the blood; called also erythrocythemia, hypercythemia, and hypererythrocythemia.

There are two distinct forms of the disease: Primary polycythemia (polycythemia vera) is a myeloproliferative disorder of unknown etiology. It is characterized by hyperplasia of the cell-forming tissues of the bone marrow, with resultant elevation of the erythrocyte count and hemoglobin level, and an increase in the number of leukocytes and platelets.

Secondary polycythemia is a physiologic condition resulting from a deficient oxygen supply to the tissues. The body attempts to compensate for the deficiency by manufacturing more hemoglobin and erythrocytes. Living at high altitudes can produce polycythemia, as can severe chronic lung and heart disorders, especially congenital heart defects.

Absolute polycythemia refers to an increase in red cell mass from any cause. Relative polycythemia refers to a loss of plasma volume causing an elevated hematocrit.

Symptoms. The symptoms of primary and secondary polycythemia are much the same. The increased erythrocyte production results in thickening of the blood and an increased tendency toward clotting. The viscosity of the blood limits its ability to flow properly, so that the supply to the brain and other vital tissues is diminished. This may cause sluggishness, irritability, headache, dizziness, fainting, disturbances of sensation in the hands and feet, and a feeling of fullness in the head. There may be episodes of acute pain as spontaneous clots occur in the blood vessels. The spleen becomes enlarged and the smaller veins become more prominent, so that the skin has a bluish hue. The secondary form is often accompanied by enlargement of the tips of the fingers (clubbing).

Treatment. Treatment of polycythemia vera is aimed at reducing the red cell count and decreasing the blood volume. Mild cases can be managed by periodic phlebotomy. More serious cases may require myelosuppressive therapy; interferon and large-dose aspirin therapy may also be used. Research on treatment modalities is ongoing. In secondary polycythemia, successful treatment of the causative illness will relieve the polycythemia.

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polycythemia (pol´ēsīthē´mē),

n an increase in blood volume as a result of an increase in the number of red blood cells, the erythrocytes. It may result from a blood-forming disease that increases cell production, or it may be a physiologic response to an increased need for oxygenation in high altitudes, cardiac disease, or respiratory disorders.

polycythemia, phlebotomy for,

n the drawing of blood to check for an overabundance of red blood cells.

polycythemia, primary,

n See erythremia.

polycythemia, relative,

n an overabundance of red blood cells due to plasma loss.

polycythemia rubra,

n See erythremia.

polycythemia, secondary,

n See erythrocytosis.

polycythemia vera,

n See erythremia.

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polycythemia

an increase in the circulating red blood cell mass.

There are two distinct forms:

Primary polycythemia is a myeloproliferative disorder of unknown etiology. It occurs as an inherited defect in cattle and is a rare disease in dogs and cats. There is hyperplasia of the cell-forming tissues of the bone marrow, with resultant elevation of the erythrocyte count and hemoglobin level, and an increase in the number of leukocytes and platelets. Called also polycythemia vera.

Secondary polycythemia is a physiological condition resulting from a decreased oxygen supply to the tissues, caused by living at high altitudes, heart disease, circulatory insufficiency or severe pulmonary disease, or the production of erythropoietin or erythropoietin-like compounds, as in polycystic kidney disease, hydronephrosis or renal neoplasms.

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absolute polycythemia

an increase in total hemoglobin and red cell mass with a normal plasma volume. May be a primary or secondary polycythemia.

compensatory polycythemia

a secondary polycythemia, occurring in response to impairment of oxygenation.

familial polycythemia

occurs as an autosomal recessive trait in Jersey cattle. See primary polycythemia (above).

inherited polycythemia

an inherited defect of cattle. Clinically there is dyspnea.

relative polycythemia

apparent polycythemia resulting from loss of plasma and the hemoconcentration that follows. Called also spurious polycythemia.

polycythemia vera

see primary polycythemia (above).

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polycythemia

Any ↑ RBC mass See Relative polycythemia, Secondary polycythemia

Polycythemia types

Relative RBC mass is above normal but not pathologic See Relative polycythemia

Secondary to various physiopathologic mechanisms, usually hypoxia or ↑ erythropoietin secretion

Neoplastic, ie polycythemia vera, see there