F - Hematological disorders - Polycythemia Wk8 Flashcards
What are the causes & risk factors of secondary polycythemia?
- conditions associated with tissue hypoxia,
- eg high altitude, chronic obstructive pulmonary disease, cyanotic heart disease. - renal conditions
- eg renal artery stenosis, renal cysts, and renal tumors - Erythropoietin secreting tumors
- eg hepatocellular carcinoma - Side effects of some Medications
- eg erythropoietin analogs, testosterone anabolic steroids
Risk factors:
- smoking
- chronic alcoholism
- obesity, hypertension
What are the causes & risk factors of primary polycythemia?
- chronic myeloproliferative disorder caused by acquired mutation of the JAK2 gene
- codes for a protein that promotes cell growth and proliferation
Risk factors:
1. assigned male at birth
2. > 50 years
Whats Polycythemia?
- increased number of circulating RBCs
- either primary: spontaneous increase in the production of RBCs or
- secondary: another condition causes increased production
pathology of polycythemia
. In primary polycythemia, the mutation of the JAK2 gene causes hematopoietic cells to divide even in the absence of erythropoietin. As a result, there’s overproduction of primarily red blood cells, but also white blood cells and platelets.
On the other hand, with secondary polycythemia, tissue hypoxia stimulates the production of erythropoietin, which increases the production of red blood cells, eventually causing polycythemia.
In both types of polycythemia, the increased the volume and viscosity of the blood ultimately causes sluggish blood flow, congestion in the peripheral organs,
and tissue hypoxia and ischemia.
RBCs have an important role in maintaining the acid-base balance in the body.
production of red blood cells starts in the bone marrow, where the hematopoietic stem cells reside.
In order to proliferate and reach their mature form, hematopoietic cells require stimulation by specific growth factors. One of these factors is a hormone called erythropoietin, produced by kidneys. Once produced, erythropoietin enters the blood and travels to the bone marrow, where it signals hematopoietic cells to differentiate into red blood cells.
Moreover, if there’s tissue hypoxia or low levels of oxygen in peripheral tissues, the kidneys can increase the production of erythropoietin, therefore ramping up the production of red blood cells.
Finally, the other two groups of blood cells include white blood cells, which primarily defend the body from foreign pathogens; and platelets, which have a key role in blood clotting and hemostasis.
clinical manifestations of polycythemia
are often caused by blood vessel congestion.
When cerebral circulation is affected, there’s dizziness and headaches; retinal vessel congestion causes blurred vision;
impaired peripheral circulation can cause tingling or burning in the hands and feet; additionally, when there’s pain, swelling and redness in the hands and feet, it’s called erythromelalgia and this can be triggered by stress, exercise, temperature change, or dehydration.
There can also be facial plethora which is ruddy complexion.
Another common symptom is pruritus, or itchiness, especially after a hot shower or bath, and this is likely due to overproduction of histamine and prostaglandins by mast cells. There can also be systemic effects, like fatigue, from a combination of hypoxia and iron deficiency.
Other important clinical features include hypertension due to hypervolemia, and cyanosis of visible mucosa. Although there’s an increased number of platelets, they can function abnormally, causing nose bleeds, gum bleeds and petechiae, which are red, flat, pinpoint spots on the skin.
Finally, an enlarged liver or spleen that can cause abdominal fullness or pain and can be felt on palpation.
complications of polycythemia
- increased viscosity of the blood and circulatory congestion, because these factors increase the risk of developing blood clots or thrombosis.
The most common thrombotic complications include stroke, angina pectoris, myocardial infarction, and deep vein thrombosis.
Additionally, high turnover of red blood cells is characterized by increased levels of uric acid in the body, which can result in complications such as kidney stones and gout, which is a type of joint inflammation caused by high levels of uric acid.
Other important complications include peptic ulcers, hepatomegaly, and splenomegaly. Moreover, splenomegaly occurs because the spleen is trying to eliminate the excess blood cells from circulation.
Diagnosis
complete blood cell count, which typically reveals an increased hematocrit, as well as increased hemoglobin, WBCs, RBCs , and platelets.
Primary polycythemia can also be diagnosed using genetic testing to look for mutations in the JAK2 gene;
while clients with secondary polycythemia might require imaging methods, such as ultrasound, X-ray, and MRI, to detect the cause of secondary polycythemia.
For both types of polycythemia, serum erythropoietin levels can be used to differentiate between the two. Clients with primary polycythemia have low erythropoietin levels because the mutation of the JAK2 gene stimulates the production of red blood cells in the absence of erythropoietin. At the same time, the increased number of RBCs suppresses erythropoietin levels. On the flip side, clients with secondary polycythemia usually have high erythropoietin levels, because there’s tissue hypoxia or tumor that increases the production of erythropoietin. Finally, if a bone marrow biopsy is performed, it can show hypercellularity, as well as hyperplasia of all blood cell lines, in both primary and secondary polycythemia.
Treatment of polycythemia
- therapeutic phlebotomy, which is a procedure where 500 mL of blood is drawn every week from a vein to reduce the blood volume and viscosity until lab values like hematocrit decrease.
2, increase fluid intake & take low dose aspirin - decrease the risk of blood clotting
- myelosuppressive agents
- suppress bone marrow and the production of blood cells,
- allopurinol: reduce uric acid production
individuals with secondary polycythemia require the treatment of the primary condition that caused polycythemia.
nursing care you’ll provide for a client with polycythemia vera. Your priority nursing goals are to manage your client’s symptoms and monitor for complications.
Begin by assessing your client’s vital signs, especially their blood pressure. Also check their CBC and note their RBC count and hematocrit. Then, assist with therapeutic phlebotomy, and administer the prescribed IV fluids to reduce blood volume and viscosity. Also administer the prescribed myelosuppressive medication to help reduce production of RBCs and other blood cells in the bone marrow.
After treatment, monitor you client closely, and immediately report to the healthcare provider if your client develops hypertension; thrombotic symptoms, including pain, redness, or swelling in the calf; chest pain; a sudden onset of dyspnea, or stroke-like symptoms; and prepare to administer antithrombotics or anticoagulants as ordered.
Next, address complications of the disease, including bleeding, altered nutrition, and pruritus. Let’s start with bleeding, monitor the client closely for unusual bleeding, and report the presence of epistaxis or petechiae to the healthcare provider.
Assess their nutritional status and ask them about their appetite and usual diet. Provide small, nutrient dense, high calorie meals, and request a nutrition consult, as needed.
For pruritus, administer the prescribed antihistamine, apply cool compresses, and keep their skin moisturized.
client and family teaching. First, teach your client that polycythemia is a condition where the bone marrow makes too many red blood cells, which causes the blood to become thick, which then slows circulation and decreases oxygen delivery to the body.
Then, review the plan of care and stress the importance of adhering to the prescribed treatments, including routine phlebotomy and medications.
Next, encourage lifestyle modifications, including a heart healthy diet and drinking enough fluids to keep their urine pale yellow. Stress the importance of avoiding any product that contains nicotine or tobacco, like cigarettes, e-cigarettes, or chewing tobacco; and if they need help quitting, support them by providing counseling and resources.
Also encourage moderate physical activity, and help them to deal with fatigue by balancing activity with periods of rest. Lastly, remind them to promote circulation by taking regular breaks to get up, stretch, and walk around during prolonged periods of sitting.
If your client experiences pruritus, suggest they take lukewarm baths, to keep their skin moisturized, to avoid scratching, and to take their prescribed antihistamine, as directed. If the pruritus negatively impacts their quality of life, encourage them to contact their healthcare provider to discuss other treatment options.
Finally, instruct your client to seek medical attention immediately if they experience signs of a stroke such as confusion, trouble speaking, or sudden numbness or weakness; chest pain or trouble breathing; if they have sudden abdominal or flank pain; or if they have blood in their stool or vomit.
