Sickle Cell Disease

Question 1

Intrinsic: Sickle Cell Disease (SCD)

Answer 1

• Group of inherited, autosomal recessive disorders
• Presence of an abnormal form of hemoglobin in the erythrocyte
• Hemoglobin S (HbS), abnormal

Question 2

HbS causes the RBC to stiffen and elongate

Answer 2

• sickle shape in response to decrease in O2
• Substitution of valine for glutamic acid on the B-globin chain of hemoglobin
  genetic disorder
  Incurable disease, often fatal
• because this is a genetic disorder, SCD is usually identified during infancy or early childhood
• SCD affects are predominantly in those of African descent, occuring in an estimated prevalence of 1 in about 400 live births. It can also affect people of Mediterranean, Caribbean, South and Central American, Arabian, or East Indian ancestry

Question 3

SCD - Etiology and Pathophysiology

Answer 3

- Types of SCD 
Sickle cell anemia (most severe, homozygous for hemoglobin S (HbSS) 
Sickle cell-thalassemia
Sickle cell-HbC disease 
Sickle cell train (HbAS)

Question 4

Sickle Cell Hemoglobin Aggregates and Alters Shape of RBC

Answer 4

• Sickled RBCs become rigid and take on an elongated, crescent shape. Sickled cells cannot easily pass through capillaries or other small vessels and can cause vascular occlusion, leading to acute or chronic tissue injury. The resulting hemostasis promotes a self-perpetuating cycle of local hypoxia, deoxygenation of more erythrocytes, and more sickling. Circulating sickled cells are hemolyzed by the spleen, leading to anemia.

Question 5

SCD - Clinical manifestations

Answer 5

• Typical client is asymptomatic, except during sickling episodes
• Symptoms may include (pain and swelling, pallor of mucous membranes, jaundice)
• Sickling episodes can affect any area of the body or several sites simultaneously, with the back, chest, extremities and abdomen being most commonly affected. Pain severity can range from trivial to excruciating.
• pain episodes are often accompanied by objective clinical signs such as fever, swelling, tenderness, tachypnea, hypertension, nausea, and vomiting

Question 6

SCD - Complications

Answer 6

• Gradual involvement of all. body systems
• Prone to infection (pneumonia, most common infection)
• Acute chest syndrome
• organs that are most commonly affected are the spleen, lungs, kidneys, and brain
• one reason that clients are susceptible to infection is failure of the spleen to phagocytize foreign substances, as it becomes infarcted and dysfunctional (usually 2-4 years of age) from the sickled red cells
• Acute chest syndrome is characterized by fever, chest pain, cough, pulmonary infiltrates, and dyspnea
• Pulmonary infarctions may cause pulmonary hypertension, MI, HF, and ultimately cor pulmonaie.

Question 7

SCD - Diagnostic Studies

Answer 7

• peripheral blood smear
• sickling test
• Electrophoresis of hemoglobin
• Skeletal radiographs
• Magnetic resonance imaging (MRI)

Question 8

SCD - Nursing Management

Answer 8

• alleviate symptoms of disease complications
• minimize end target-organ damage
• No specific treatment for SCD
• Client teaching (avoid high altitudes, maintain fluid intake, treat infections, help with pain control)
• chronic leg ulcers may be treated with rest, antibiotics, warm saline soaks, debridement, and grafting if necessary

Question 9

SCD - Nursing management

Answer 9

• O2 for hypoxia and to control sickling
• Pain management
• Acute chest syndrome (antibiotics, O2 therapy, fluid therapy, transfusions, if needed)
• rest may be instituted to reduce metabolic requirements, and DVT prophylaxis (using anticoagulants) may be prescribed. Fluids and electrolytes are administered to reduce blood viscosity and maintain renal function.
• during an acute crisis, optimal pain control usually includes large doses of continuous (rather than as-needed) opioid analgesics along with breakthrough analgesia, often in the form of client-controlled analgesia. Morphine and hydromorphone are the drugs of choice.

Question 10

SCD - Nursing Management

Answer 10

• Blood transfusions in crisis
• Hydroxyurea: antisickling agent
  Erythropoietin in clients unresponsive to hydroxyurea
• Hematopoietic stem cell transplant
  Can cure come clients with SCD
• Hydroxyurea increases the production of hemoglobin F (fetal hemoglobin), decreases the reactive neutrophil count, increases erythrocyte volume and hydration, and alters the adhesion of sickle erythrocytes to the endothelium