The thalassemias are inherited disorders of hemoglobin (Hb) synthesis.
What is Thalassemia?
The term thalassemia is applied to a variety of inherited blood disorders characterized by deficiencies in the rate of production of specific globin chains in hemoglobin.
- The thalassemias are inherited disorders of hemoglobin (Hb) synthesis.
- Thalassemia major (Cooley’s anemia) presents in childhood and is the most common.
- The disorder often occurs in people of Mediterranean descent but may also be seen in other populations.
The thalassemias are inherited disorders of Hb synthesis that result from an alteration in the rate of globin chain production.
- A decrease in the rate of production of a certain globin chain or chains (α, β, γ, δ) impedes Hb synthesis and creates an imbalance with the other, normally produced globin chains.
- Because 2 types of chains (α and non-α) pair with each other at a ratio close to 1:1 to form normal Hbs, an excess of the normally produced type is present and accumulates in the cell as an unstable product, leading to the destruction of the cell.
- The type of thalassemia usually carries the name of the underproduced chain or chains.
- For example, when β chains are produced at a lower rate, the thalassemia is termed β+, whereas β-0 thalassemia indicates a complete absence of production of β chains from the involved allele.
- The consequences of the impaired production of globin chains ultimately result in the deposition of less Hb into each RBC, leading to hypochromasia.
- The Hb deficiency causes RBCs to be smaller, leading to the classic hypochromic and microcytic picture of thalassemia.
- In the most common type of β thalassemia trait, the level of Hb A2 (δ2/α2) is usually elevated.
- β thalassemia is mostly related to a point mutation in the β globin gene.
- In the severe forms, such as β thalassemia major or Cooley anemia, the same pathophysiology applies with substantial exaggeration.
- The significant excess of free α chains caused by the deficiency of β chains causes the destruction of the RBC precursors in the bone marrow.
Statistics and Incidences
Because of immigration to the United States from all parts of the world and the intermarriages that have taken place over the years, all types of thalassemia occur in any given part of the country.
- However, until recently, the number of patients with severe forms of both β and α thalassemia has been very limited.
- For this reason, finding more than 2-5 patients with the very severe forms in any pediatric hematology center is unusual (except for in the few referral centers in the United States).
- The interaction between Hb E (a β chain variant) and β thalassemia (both very common among Southeast Asians) has created the Hb E/β thalassemia entity, which is now believed to be the most common thalassemia disorder in many regions of the world, including coastal North America, thus replacing β thalassemia major in frequency.
- In California alone, 10-14 new cases of β thalassemia major and Hb E/β thalassemia and 40 cases of neonatal Hb H disease are detected annually.
- Worldwide, 15 million people have clinically apparent thalassemic disorders.
- Reportedly, disorders worldwide, and people who carry thalassemia in India alone number approximately 30 million.
The onset is usually insidious and not recognized until the latter half of infancy.
- Anemia. Signs of anemia- unexplained fever, poor feeding, and a markedly enlarged spleen– particularly in a child of Mediterranean extraction, are descriptive.
- Fatigue. The decrease of circulating RBCs that bring about oxygen to all parts of the body can lead to fatigue.
- Pallor. Decrease in production of RBCs leads to pallor.
- Irritability. The child may feel irritable due to a feeling of discomfort.
- Anorexia. Anorexia is apparent in a child with thalassemia.
Assessment and Diagnostic Findings
Laboratory and imaging studies in thalassemia include the following:
- CBC count and peripheral blood smear. The CBC count and peripheral blood film examination results are usually sufficient to suspect the diagnosis.
- Iron studies. Serum iron level is elevated, with saturation reaching as high as 80%; the serum ferritin level, which is frequently used to monitor the status of iron overload, is also elevated.
- Skeletal survey. Skeletal survey and other imaging studies reveal classic changes of the bones that are usually encountered in patients who are not regularly transfused.
- ECG. ECG and echocardiography are performed to monitor cardiac function.
- HLA typing. HLA typing is performed for patients for whom bone marrow transplantation is considered.
The objective of supportive therapy is to maintain sufficient hemoglobin levels to prevent tissue hypoxia.
- Splenectomy. Splenectomy is the principal surgical procedure used for many patients with thalassemia.
- Transfusions. Transfusions are the foundation of medical management; recent studies have evaluated the benefits of maintaining the child’s hemoglobin level above 10g/dl, a goal that may require transfusions as often as every 2-4 weeks.
- Bone marrow transplantation. Bone marrow transplantation offers the possibility of a cure for some children with thalassemia, either using marrow from an unaffected sibling, or a matched, unrelated donor.
- Diet. A normal diet is recommended, with emphasis on the following supplements: folic acid, small doses of ascorbic acid (vitamin C), and alpha-tocopherol (vitamin E); iron should not be given, and foods rich in iron should be avoided.
Medications needed for the treatment of various types of thalassemias are nonspecific and only supportive.
- Antipyretics. Administration before blood transfusion prevents or decreases febrile reactions.
- Antihistamines. Administration prior to blood transfusion may decrease or prevent allergic reactions.
- Chelating agents. These agents are used to chelate excessive iron from the body in patients with iron overload.
- Corticosteroids. Some patients may develop a local reaction at the site of DFO injection; hydrocortisone in the DFO solution may help to reduce the reaction.
- Antibacterial combinations. Certain antibacterial agents are known to be effective against organisms that often cause infection in patients with iron overload who also are receiving DFO therapy.
- Vitamins. Several vitamins are required such as vitamin C, folic acid, and alpha-tocopherol, as either supplements or enhancers of the chelating agent; serum level of vitamin C is low in patients with thalassemia major, likely due to increased consumption in the face of iron overload.
- Vaccines. Splenectomized patients are usually prone to developing infections with the encapsulated organisms such as pneumococci, Haemophilus influenzae, and meningococcal organisms; for this reason, such patients now are immunized against these organisms 1-2 wk prior to the procedure to prevent infections.
- Antineoplastic agents. Some patients may respond to hydroxyurea and subsequently decrease or eliminate transfusion requirements.
- Growth hormone. Excessive chelation with deferoxamine may cause growth retardation; growth hormone may be effective in increasing growth rate in all thalassemic patient particularly the ones with growth hormone deficiency.
Nursing care of a child with thalassemia should also be supportive.
Nursing assessment of a child with thalassemia include:
- Thalassemia major. Assess for severe anemia, splenomegaly or hepatomegaly with abdominal enlargement, frequent infections, bleeding tendencies e.g. epistaxis, and anorexia.
- Thalassemia intermediate. Assess for anemia, jaundice, and splenomegaly, hemosiderosis caused by increased intestinal absorption of iron.
- Thalassemia minor. Assess for mild anemia usually with no signs or symptoms.
Based on the assessment data, the major nursing diagnoses are:
- Ineffective tissue perfusion related to reduced cellular components that are essential to deliver pure oxygen to the cells.
- Activity intolerance related to imbalance of oxygen supply and consumption needs.
- Imbalanced nutrition: less than body requirements related to lack of appetite.
- Ineffective family coping related to impact of the disease to family functioning.
Nursing Care Planning and Goals
Major goals for the child are:
- Client will verbalize use of energy conservation principles.
- Client will verbalize reduction of fatigue, as evidenced by reports of increased energy and ability to perform desired activities.
- Client will verbalize understanding of own disease and treatment plan.
- Client will have a reduced risk of infection as evidenced by an absence of fever, normal white blood cell count, and implementation of preventive measures such as proper hand washing.
- Client will have vital signs within the normal limit.
- Client will have a reduced risk for bleeding, as evidenced by normal or adequate platelet levels and absence of bruises and petechiae.
Nursing interventions for a child with thalassemia are:
- Activity. Assist the client in planning and prioritizing activities of daily living (ADL); assist the client in developing a schedule for daily activity and rest; and stress the importance of frequent rest periods.
- Health education. Explain the importance of the diagnostic procedures (such as complete blood count), bone marrow aspiration and a possible referral to a hematologist; and explain the hematological vocabulary and the functions of blood elements, such as white blood cells, red blood cells, and platelets.
- Prevent infection. Assess for local or systemic signs of infection, such as fever, chills, swelling, pain, and body malaise; instruct the client to avoid contact with people with existing infections; instruct the client to avoid eating raw fruits and vegetables and uncooked meat; stress the importance of daily hygiene, mouth care, and perineal care; and teach the client and visitors the proper hand washing.
- Prevent bleeding. Assess for any frank bleeding from the nose, gums, vagina, or urinary or gastrointestinal tract and monitor platelet count.
Goals are met as evidenced by:
- Client/parent verbalized use of energy conservation principles.
- Client verbalized reduction of fatigue, as evidenced by reports of increased energy and ability to perform desired activities.
- Client/parent verbalized understanding of own disease and treatment plan.
- Client has a reduced risk of infection as evidenced by an absence of fever, normal white blood cell count, and implementation of preventive measures such as proper hand washing.
- Client has vital signs within the normal limit.
- Client has a reduced risk for bleeding, as evidenced by normal or adequate platelet levels and absence of bruises and petechiae.
Documentation in a child with thalassemia include:
- Baseline and subsequent assessment findings to include signs and symptoms.
- Individual cultural or religious restrictions and personal preferences.
- Plan of care and persons involved.
- Teaching plan.
- Client’s responses to teachings, interventions, and actions performed.
- Attainment or progress toward desired outcome.
- Long-term needs, and who is responsible for actions to be taken.
Practice Quiz: Thalassemia
1. A child with thalassemia was given deferoxamine (Desferal); which of the following should alert the nurse to notify the physician?
1. Answer: A. Decreased hearing.
- Option A: Desferoxamine is ototoxic. Thus, any hearing problem should be immediately addressed to the physician.
- Option B: Hypotension, not hypertension, is a possible adverse effect.
- Option C: Red urine is an expected occurrence with deferoxamine.
- Option D: Vomiting is not an emergency with this drug.
2. The long-term complications seen in thalassemia major are associated to which of the following?
B. Growth retardation.
2. Answer: C. Hemochromatosis.
- Option C: Long-term complications arise from hemochromatosis, excessive iron deposits precipitating in the tissues and causing destruction.
- Option A: Anemia is a sign of this disorder.
- Options B and D: Cellular damage from hemochromatosis may lead to splenomegaly, growth retardation, skeletal complications, cardiac problems, gallbladder disease, hepatomegaly, and skin changes.
3. A child with β-thalassemia is undergoing a blood transfusion. To prevent organ damage from the excessive amount of iron, chelation therapy is prescribed. Which of the following medications will be added to this therapy?
3. Answer: C. Deferasirox.
- Option C: Chelation therapy with deferasirox (Exjade) or deferoxamine (Desferal) is prescribed to prevent organ damage from the presence of too much iron in the body as a result of the transfusion.
- Option A is a cough suppressant.
- Option B is a thrombin inhibitor.
- Option D is an antidepressant.
4. A clinic patient has a hemoglobin concentration of 10.8 g/dL and reports sticking to a strict vegetarian diet. Which of the following nutritional advice is appropriate?
A. The diet is providing adequate sources of iron and requires no changes.
B. The patient should add meat to her diet; a vegetarian diet is not advised.
C. A cup of coffee or tea should be added to every meal.
D. The patient should use iron cookware to prepare foods, such as dark-green, leafy vegetables and legumes, which are high in iron.
4. Answer: D. The patient should use iron cookware to prepare foods, such as dark green, leafy vegetables and legumes, which are high in iron.
- Option D: Normal hemoglobin values range from 11.5-15.0. This vegetarian patient is mildly anemic. When food is prepared in iron cookware its iron content is increased.
- Option A: In addition, dark green leafy vegetables, such as spinach and kale, and legumes are high in iron.
- Option B: Mild anemia does not require that animal sources of iron be added to the diet. Many non-animal sources are available.
- Option C: Coffee and tea increase gastrointestinal activity and inhibit absorption of iron.
5. Halfway through the administration of blood, the female client complains of lumbar pain. After stopping the infusion Nurse Hazel should:
A. Increase the flow of normal saline.
B. Assess the pain further.
C. Notify the blood bank.
D. Obtain vital signs.
5. Answer: A. Increase the flow of normal saline.
- Option A: The blood must be stopped at once, and then normal saline should be infused to keep the line patent and maintain blood volume.
- Options B, C, D: These actions should follow after increasing the flow of normal saline.