What is Thalassemia?
Thalassemia is a group of inherited disorders of hemoglobin (Hb) synthesis, marked by deficient production of specific globin chains. Thalassemia major (Cooley's anemia) presents in childhood and is the most common form. It occurs often in people of Mediterranean descent but shows up in other populations too.
Pathophysiology
The defect is a reduced rate of production of one or more globin chains (α, β, γ, δ), which throws off Hb synthesis. The two chain types (α and non-α) normally pair at a ratio close to 1:1. When one chain is underproduced, the normally produced type accumulates as an unstable product inside the cell and destroys it. The thalassemia is named for the underproduced chain: β+ means β chains are produced at a lower rate, while β-0 means complete absence of β chain production from the involved allele.
Less Hb is deposited into each RBC, producing the classic hypochromic, microcytic picture. In the common β thalassemia trait, Hb A2 (δ2/α2) is usually elevated, and β thalassemia is mostly tied to a point mutation in the β globin gene. In the severe forms (β thalassemia major, Cooley anemia) the same mechanism is exaggerated: the large excess of free α chains destroys RBC precursors in the bone marrow.
Statistics and Incidences
Because of immigration and intermarriage over the years, all types of thalassemia now occur in any part of the United States, though until recently the number of patients with severe β and α forms was very limited. Finding more than 2-5 patients with the very severe forms in any pediatric hematology center is unusual, except at the few referral centers.
The interaction between Hb E (a β chain variant) and β thalassemia, both common among Southeast Asians, produced Hb E/β thalassemia, now believed to be the most common thalassemia disorder in many regions including coastal North America, replacing β thalassemia major in frequency. In California alone, 10-14 new cases of β thalassemia major and Hb E/β thalassemia, plus 40 cases of neonatal Hb H disease, are detected annually. Worldwide, 15 million people have clinically apparent thalassemic disorders, and carriers in India alone number approximately 30 million.
Clinical Manifestations
Onset is usually insidious and not recognized until the latter half of infancy. Watch for signs of anemia: unexplained fever, poor feeding, and a markedly enlarged spleen, particularly in a child of Mediterranean extraction. Fewer circulating RBCs delivering oxygen drives fatigue and pallor. The child may be irritable from discomfort, and anorexia is common.
Assessment and Diagnostic Findings
The CBC count and peripheral blood film are usually enough to suspect the diagnosis. Iron studies show an elevated serum iron level with saturation reaching as high as 80%; serum ferritin, used to monitor iron overload, is also elevated. A skeletal survey reveals the classic bone changes seen in patients who are not regularly transfused. ECG and echocardiography monitor cardiac function. HLA typing is done when bone marrow transplantation is considered.
Medical Management
Supportive therapy aims to maintain enough hemoglobin to prevent tissue hypoxia. Transfusions are the foundation: people with beta thalassemia major often need regular transfusions about every 3 to 4 weeks to maintain healthy hemoglobin and prevent tissue hypoxia (NHLBI). Splenectomy is the principal surgical procedure for many patients. Bone marrow transplantation offers a possible cure for some children, using marrow from an unaffected sibling or a matched, unrelated donor.
A normal diet is recommended with emphasis on folic acid, small doses of ascorbic acid (vitamin C), and alpha-tocopherol (vitamin E). Do not give iron, and avoid iron-rich foods.
Pharmacologic Management
Medications are nonspecific and supportive. Antipyretics before transfusion prevent or reduce febrile reactions, and antihistamines before transfusion reduce allergic reactions. Chelating agents remove excess iron in patients with iron overload; because regular transfusions cause iron to build up to potentially life-threatening levels, iron chelation therapy is standard for transfusion-dependent patients (NHLBI, CDC). For the local reaction some patients develop at the deferoxamine (DFO) injection site, hydrocortisone added to the DFO solution can reduce it, and certain antibacterial combinations are effective against organisms that infect iron-overloaded patients on DFO. Vitamin C, folic acid, and alpha-tocopherol serve as supplements or as enhancers of the chelating agent; serum vitamin C runs low in thalassemia major, likely from increased consumption under iron overload.
Splenectomized patients are prone to infection from encapsulated organisms (pneumococci, Haemophilus influenzae, meningococcal organisms), so immunize them 1-2 weeks before the procedure. Some patients respond to hydroxyurea and reduce or eliminate transfusion needs. Excessive chelation with deferoxamine can cause growth retardation; growth hormone may raise the growth rate, especially in patients with growth hormone deficiency.
Nursing Management
Nursing care is supportive and assessment-driven.
Nursing Assessment
In thalassemia major, assess for severe anemia, splenomegaly or hepatomegaly with abdominal enlargement, frequent infections, bleeding tendencies (such as epistaxis), and anorexia. In thalassemia intermedia, assess for anemia, jaundice, splenomegaly, and hemosiderosis from increased intestinal iron absorption. In thalassemia minor, expect mild anemia, usually without signs or symptoms.
Nursing Diagnoses
Based on the assessment data, major nursing diagnoses include ineffective tissue perfusion related to reduced cellular components needed to deliver oxygen; activity intolerance related to imbalance between oxygen supply and demand; imbalanced nutrition, less than body requirements, related to poor appetite; and ineffective family coping related to the disease's impact on family functioning.
Nursing Care Planning and Goals
The child will use energy conservation principles and report reduced fatigue with increased energy and ability to do desired activities. The child will understand the disease and treatment plan, carry a reduced infection risk (no fever, normal WBC count, preventive measures such as proper handwashing), maintain vital signs within normal limits, and carry a reduced bleeding risk (adequate platelet levels, no bruises or petechiae).
Nursing Interventions
Help the child plan and prioritize activities of daily living, build a schedule of activity and rest, and stress frequent rest periods. Explain the diagnostic procedures (CBC, bone marrow aspiration, possible hematology referral) and the functions of blood elements such as white cells, red cells, and platelets.
To prevent infection, assess for local or systemic signs (fever, chills, swelling, pain, malaise), keep the child away from people with active infections, avoid raw fruits, vegetables, and uncooked meat, and stress daily hygiene, mouth care, perineal care, and proper handwashing for the child and visitors. To prevent bleeding, assess for frank bleeding from the nose, gums, vagina, or urinary or GI tract, and monitor the platelet count.
Evaluation
Goals are met when the child or parent verbalizes use of energy conservation principles and understanding of the disease and treatment plan, reports reduced fatigue, and the child shows reduced infection risk (no fever, normal WBC count, preventive measures in place), vital signs within normal limits, and reduced bleeding risk (adequate platelets, no bruises or petechiae).
Documentation Guidelines
Document baseline and subsequent assessment findings including signs and symptoms; cultural or religious restrictions and personal preferences; the plan of care and persons involved; the teaching plan; the child's responses to teaching and interventions; attainment of or progress toward desired outcomes; and long-term needs with responsibility for actions to be taken.
Frequently Asked Questions
What is thalassemia? It is a group of inherited blood disorders in which the body makes too little of one or more globin chains, so it cannot produce enough normal hemoglobin. The result is fewer, shorter-lived red blood cells and anemia (CDC).
What is the difference between thalassemia major, intermedia, and minor? Major (Cooley anemia) is the severe, transfusion-dependent form that appears in infancy. Intermedia is moderate, with anemia, jaundice, and splenomegaly. Minor (trait) usually causes only mild anemia, often without symptoms.
Why is iron overload a problem if the patient is anemic? The anemia comes from defective hemoglobin, not iron deficiency. Repeated transfusions add iron the body cannot excrete, so it accumulates in the heart, liver, and endocrine organs. Do not give iron, and use chelation to remove the excess (NHLBI).
Can thalassemia be cured? A bone marrow or stem cell transplant from a matched donor can cure some children. Most patients are managed long term with transfusions and iron chelation (NHLBI).
Why are splenectomized patients vaccinated before surgery? Removing the spleen raises the risk of infection from encapsulated organisms (pneumococci, Haemophilus influenzae, meningococci), so immunize 1 to 2 weeks before the procedure.
What diet is recommended? A normal diet with folic acid and small doses of vitamin C and vitamin E; iron supplements and iron-rich foods are avoided.