Learning Objectives
By the end of this section, you will be able to:
- Discuss the pathophysiology, risk factors, and clinical manifestations associated with hereditary hematological disorders
- Describe the diagnostics and laboratory values of hereditary hematological disorders
- Apply nursing concepts and plan associated nursing care for the patient with a hereditary hematological disorder
- Evaluate the efficacy of nursing care for the patient with a hereditary hematological disorder
- Describe the medical therapies for hereditary hematological disorders
Hereditary blood disorders include sickle cell anemia and thalassemia. These inherited disorders disrupt the structure, function, or production of Hb, the protein that transports oxygen in RBCs. These disorders have an enormous effect on individuals and their families, often necessitating lifelong medical treatment and management. Understanding the genetic mechanisms, clinical manifestations, and treatments available for hereditary blood disorders is important for health-care professionals because they play an essential part in diagnosing, caring for, and supporting those who have these chronic conditions.
Sickle Cell Anemia
An inherited blood disorder caused by abnormal Hb production that results in RBCs forming into crescent-shaped “sickles” is called sickle cell disease. Of the many types of sickle cell diseases, the one that causes severe anemia is called sickle cell anemia (SCA). Like other sickle cell diseases, SCA is characterized by abnormal production of Hb caused by a genetic mutation; in the case of SCA, however, RBCs become rigid and sticky before taking on their characteristic crescent shape (sickle). As a result, the RBCs block vessels and may eventually prevent blood from reaching organs (Figure 16.2). SCA most often affects individuals of African, Mediterranean, Middle Eastern, or South Asian descent; presents as acute pain crises or long-term organ damage; and affects mortality and morbidity.
Clinical Manifestations
SCA clinical manifestations vary significantly from patient to patient. Generally, they are like symptoms for other kinds of anemia, but the resulting pain may be worse, particularly during a vaso-occlusive crisis. Also known as a pain crisis or sickle cell crisis, this is when sickle-shaped RBCs block circulation through small vessels, causing tissue ischemia, which can lead to infection and permanent tissue damage. SCA also increases the risk for stroke among children, because of smaller blood vessels. Effective management of SCA generally includes pain management, blood transfusions, medication (e.g., hydroxyurea), and sometimes bone marrow or stem cell transplantation. People living with SCA require lifelong medical supervision to control symptoms and avoid complications.
It is important to distinguish between having SCA and being in a sickle cell crisis. People with the genetic abnormality for sickle cell disease may be asymptomatic for years until a crisis occurs, which often is due to another issue, such as an infection, trauma, accident, or emotional upset. Crises may also be caused by conditions that create a demand for more RBCs, such as high altitude or strenuous exercise (Mangla et al., 2023). Clinical manifestations of SCA include
- damage to the organs such as the spleen, heart, lungs, and kidneys
- delayed growth and development, seen mostly in children, due to tissue hypoxemia and hypoxia
- fatigue from hypoxemia due to ineffective RBCs
- frequent infections from poor blood flow due to clogged vessels from sickled cells
- leg ulcers from poor blood flow to lower limbs
- pain
- presenting as a yellow hue to the skin, jaundice results from the body breaking down RBCs, releasing the heme portion
- swelling of hands and feet, that may be identified in childhood, often called “hand-foot syndrome” or dactylitis
Note that severity and frequency of signs and symptoms can differ for every individual with SCA (Mangla et al., 2023).
Diagnostics and Laboratory Values
The following laboratory and diagnostic tests can be used during the diagnostic process, as well as for continued monitoring of the sickle cell condition:
- A bone marrow aspiration is used to verify SCA by measuring the production of RBCs in the bone marrow. It is often performed alongside a bone marrow biopsy.
- A complete blood count (CBC) measures the amount of RBCs, WBCs, and platelets in a blood sample. SCA often presents with low RBC counts.
- A total bilirubin test measures how much bilirubin is being released into the bloodstream. SCA causes destruction of RBCs faster than they can be created. This causes strain on the liver and can result in the liver releasing bilirubin into the patient’s system, causing jaundice in some instances.
- Genetic testing can verify specific mutations associated with SCA and is often used for prenatal counseling to determine whether individuals are carriers for the disease.
- A hemoglobin solubility test quickly screens for sickle Hb detection, offering results in minutes. Blood samples are mixed with a reducing agent to inactivate Hb and form characteristic crystals. In positive results, there would be presence of hemoglobin S (Hb S) and sickling Hb.
- A hemoglobin electrophoresis can diagnose SCA by distinguishing different forms of Hb to detect the form and characteristics of sickle-shaped RBCs.
- A peripheral blood smear enables analysis of RBC shape and condition for diagnostic purposes. SCA is characterized by RBCs with characteristic sickle-shaped membranes.
- A reticulocyte count measures the number of young RBCs in a blood sample. As a compensatory mechanism in SCA, bone marrow produces more young RBCs into circulation than normal to replace short-living RBCs, leading to an elevated reticulocyte count.
Thalassemia
A group of hereditary blood disorders that affect the Hb genes, leading to decreased erythropoiesis, or Hb production, is referred to as thalassemia. Thalassemia mostly affects people of Mediterranean, Asian, or African descent (Mangla et al., 2023). Thalassemia can be one of the more devastating blood disorders to encounter, with symptoms ranging in severity from mild anemia to life-threatening conditions that necessitate ongoing medical intervention. Therefore, understanding its genetic, clinical, and treatment aspects is of utmost importance for providers (Bajwa & Basit, 2023).
Clinical Manifestations
Normal adult Hb is made up of two alpha and two beta protein chains. Thalassemia results from defects in Hb production. Alpha-thalassemia is a deletion of one or more of the a-globin producing genes, and beta-thalassemia is a deletion of one or more of the b-globin producing genes (Bajwa & Basit, 2023). Affected individuals may experience fatigue, weakness, pale skin tone, and shortness of breath due to insufficient oxygen-carrying capacity in their blood supply. In severe cases, it may manifest through symptoms including splenomegaly, jaundice, and bone deformities. Some individuals can remain asymptomatic carriers, whereas others require regular blood transfusions and medical monitoring.
Diagnostics and Laboratory Values
Thalassemia can be identified through specific patterns that depend upon its type (alpha or beta) and severity, as well as the frequency of transfusions necessitated by the disorder. The difference between the types is that alpha thalassemia necessitates blood transfusions in early childhood and rates of fatality at birth are higher (Barid et al., 2022).
Laboratory and diagnostic tests for thalassemia are very similar to those done for SCA. A few key tests that are used to diagnose the disorder’s type (genetic karyotyping) and disease severity are the following:
- A CBC count assesses both the quantity and quality of blood cells. Thalassemia often presents with anemia, with low levels of Hb, RBCs, and Hct.
- Hemoglobin electrophoresis is a test for identifying different types of Hb present in a blood sample and identifying any mutations. Some types of Hb include:
- hemoglobin A and A2: adult hemoglobin
- hemoglobin F: fetal hemoglobin; found in fetuses and is replaced by hemoglobin A shortly after birth
- hemoglobin E, S, C, H, and M: abnormal Hb caused by genetic mutations
- Thalassemia may lead to increases in hemoglobin A2 as well as hemoglobin F. Quantifying these components in a blood sample helps accurately diagnose thalassemia.
- Iron studies may reveal altered iron levels in a patient with thalassemia due to frequent blood transfusions. Ferritin levels and iron concentration in the blood can be measured to detect iron overload.
- A peripheral blood smear examination provides information regarding the size, shape, and color of RBCs present in a specimen. Thalassemia can be identified by hypochromic and microcytic RBCs.
- Genetic testing can detect specific mutations of globin genes to confirm diagnosis and provide more details on the Hb type.
- If necessary, a bone marrow biopsy specimen can be collected and used to help evaluate RBC production within bone marrow to confirm a diagnosis and establish treatment plans such as blood transfusions or iron chelation therapies. Regular monitoring through this testing process is crucial in managing thalassemia effectively.
Nursing Care of the Patient with a Hereditary Hematological Disorder
Nursing care for patients living with hereditary hematological disorders must incorporate both physical and emotional needs to treat patients holistically. Nurses play a pivotal role in providing necessary treatments such as blood transfusions or iron chelation therapy (discussed in detail in Medical Therapies and Related Care), monitoring dosage accuracy, and tracking potential adverse reactions. Patient education is crucial to helping individuals and their families understand the nature of hereditary disorders, the pros and cons of available treatment modalities, and the importance of taking all prescribed medication per the prescribed schedule. Essentially, the main goals of preventive measures for patients with SCA and thalassemia are to manage symptoms, reduce complications, and improve the overall quality of life.
Recognizing Cues and Analyzing Cues
To recognize and understand SCA and thalassemia, nurses must use their clinical assessment skills, review patient histories, and comprehend each disorder’s specific manifestations. Regularly monitoring vital signs and reviewing CBC counts and specific markers relating to each disorder can help nurses identify the status of the condition. Other parameters nurses are responsible for monitoring include hydration status and vaccine compliance, because dehydration and infection can trigger an exacerbation. The nurse should also help the patient identify any potential provoking factors, such as temperature variations. Additionally, collaborative communication between health-care teams as well as ongoing education of both the patient and their caregivers are integral parts of ensuring comprehensive care for individuals living with these conditions. Cues are found in the nursing health history assessment, physical assessment, laboratory results, and even psychosocial assessment. These cues help nurses obtain the relevant objective and subjective data, analyze these data, and create a nursing diagnosis and care plan.
Prioritizing Hypotheses, Generating Solutions, and Taking Action
Primary prevention is a main goal for patients with thalassemia and SCA. Nurses can identify a vaso-occlusive crisis in a patient with sickle cell disease by recognizing early dehydration or signs of infection, and then help manage pain with adequate hydration and analgesics. In acute exacerbations of sickle cell crisis, hydration with intravenous (IV) fluid replacement may be required, along with analgesics (predominantly IV opioids) to assist with pain control. In acute exacerbations of thalassemia, interventions differ in that nurses may have to administer a blood transfusion or iron chelation therapy—treatments that assist with binding to excess iron and maximize elimination. If anemia causes tissue hypoxia, the nurse can support oxygenation. For all patients with anemia, patient and family education needs to be given to empower them with better understanding of the causes, risk factors, and treatment plan for their disorder.
After tertiary interventions have been implemented, secondary prevention measures are necessary to avoid future exacerbations. Patients with SCA are encouraged to identify triggers. Promotion of adequate hydration, vaccine compliance, regular medical check-ins, and avoidance of extreme temperature fluctuations are all important elements to consider when educating patients. Patients with thalassemia are recommended to receive surveillance of Hb levels, iron studies, and whole-blood hemograms to ensure an exacerbation is not imminent. Patients with thalassemia or the trait for it may require genetic counseling when interested in pursuing family planning.
To provide holistic nursing, patients with sickle cell disease or thalassemia require further support in addition to the physical burdens. Emotional support should also be offered because these conditions typically require lifelong management. Nurses are part of the health-care teams that develop customized care plans tailored specifically to each hematological disorder, taking into account each person’s specific needs and challenges. Furthermore, nurses promote preventive measures while encouraging patients to actively take part in their treatment, instilling control and well-being amid chronic hereditary conditions.
Clinical Safety and Procedures (QSEN)
Patient-Centered Care: Care of the Patient with Sickle Cell Crisis
Patients with sickle cell disease are often at risk for vaso-occlusive crisis. Primary prevention is aimed at staying hydrated and avoiding infection by complying with vaccination recommendations. In an acute crisis, perfusion and pain are the main clinical concerns. Due to the aggregation of sickling RBCs, patients with a vaso-occlusive crisis require hospitalization, telemetry, IV fluids, and pain management. Although this disorder is usually diagnosed in the pediatric population, adults can learn how to manage with transitional programs. Community partnership and outreach with nursing support have shown promising outcomes to assist patients with sickle cell disease.
Evaluation of Nursing Care of the Patient with a Hereditary Hematological Disorder
Evaluating nursing care for patients diagnosed with hereditary hematological disorders involves an ongoing, systematic process designed to measure both intervention effectiveness and overall patient well-being. Some examples include preventing bleeding-related injuries and evaluating the patient understanding of the need to continue this practice in their daily life. Another example is promoting good skin integrity. The integrity of the skin becomes paramount to prevent wounds that may lead to bleeding complications.
Evaluating Outcomes
The nurse can evaluate patient outcomes by comparing them with initial goals set for the patient and assessing for symptom improvement. Regularly monitoring laboratory results can help the nurse compare changes against a baseline condition. For example, in patients with thalassemia, a Hb level greater than 9 g/dL would indicate that treatment was working (Bajwa & Basit, 2023). Pain management for a patient with SCA should be evaluated as early as 15 minutes after administration of pain medication and then hourly. For patients with chronic anemia, nurses should assess patient adherence to the treatment plan, including medications, blood transfusions, iron chelation therapy, or other therapeutic interventions. Collaborating with the health-care team can help the nurse evaluate patient outcomes through communication of progress with the allied health-care team.
Medical Therapies and Related Care
The treatment approach for hereditary hematologic disorders often centers on managing symptoms, avoiding complications, and improving overall quality of life. Treatment methods will depend on both the type and severity of the disorder. In acute phases, pain management with IV analgesics is common. Also, IV fluid therapy may be indicated to alleviate a vaso-occlusive crisis.
In chronic management, other conservative therapies exist. One medication is hydroxyurea, which increases the production of hemoglobin F. This makes RBCs larger, rounder, and more flexible, preventing sickle cells from forming. Bone marrow transplantation may be considered for severe cases of hereditary hematologic diseases like thalassemia; replacing defective bone marrow with healthy donor material may provide curative options. Folate supplements may support RBC production for those diagnosed with anemia (including thalassemia). Other treatments include regular blood transfusions to combat anemia and improve oxygen-carrying capacity of blood.
A treatment called iron chelation therapy is an effective method of eliminating excess iron from the body, especially among individuals receiving frequent blood transfusions that have caused the buildup of excess iron. Iron chelators are medications designed to bind to excess iron in the bloodstream, creating a compound that can then be expelled from the body through excretion. This helps avoid iron overload, which, if untreated, can result in organ damage (Kwiatkowski, 2023).