Sickle Cell Disease

Sickle Cell Disease: Excerpt from The 5-Minute Pediatric Consult

Kim Smith-Whitley, MD

Sickle Cell Disease - BASICS

Sickle Cell Disease - description

Sickle cell disease (SCD), a group of inherited hemoglobin disorders in which sickle hemoglobin (HbS) predominates, is characterized by hemolysis, vascular occlusion, and an increased risk of bacterial infection.

Sickle Cell Disease - epidemiology

• The frequencies of SCD genotypes from highest to lowest are SCD-SS (60%), SCD-SC (25–30%), SCD-Sβ⁺ thalassemia, SCD-Sβ⁰ thalassemia, and other relatively infrequent variants.
• Although population data indicate that patients with SCD-SS and SCD-Sβ⁰ thalassemia experience more complications than patients with other variants, disease severity varies widely among all individuals with SCD regardless of disease genotypes.

Sickle Cell Disease - prevalence

• 1 in 375 African American newborns has SCD.
• 1 in 12 African Americans has sickle cell trait.

Sickle Cell Disease - risk factors

Sickle Cell Disease - genetics

• SCD has an autosomal recessive inheritance.
• Common genotypes include SCD-SS, SCD-SC, SCD-Sβ⁺ thalassemia, and SCD-Sβ⁰ thalassemia.

Sickle Cell Disease - DIAGNOSIS

Sickle Cell Disease - signs & symptoms

Sickle Cell Disease - history

• SCD genotype
• Baseline hemoglobin and reticulocyte count
• Baseline pulse oximetry values (Spo
• Interval history of SCD complications
• Onset of pain, location of pain
• Prior blood transfusions and complications
• Current medications, including analgesics and hydroxyurea

Sickle Cell Disease - physical exam

• Fever
• Pallor (may be accentuated at time of splenic sequestration or transient aplastic episode)
• Scleral icterus
• Signs of respiratory distress (due to acute chest syndrome)
• Flow murmur may be present
• Splenomegaly
• Warmth, tenderness, decreased range of motion at site of pain
• Abnormal neurologic findings suggestive of CNS infarction or hemorrhage

Sickle Cell Disease - tests

Sickle Cell Disease - lab

• Diagnostic:
  • Hemoglobin electrophoresis: Definitive test along with DNA analysis
  • Screening test: “Sickledex” or “shake” tests are not recommended to establish a diagnosis or carrier status; do not use for screening in children <12 months of age, because of false-negative results.
• Monitoring:
  • CBC: Hemoglobin values vary depending on age and SCD genotype; peripheral blood smear—sickled forms, targets, nucleated RBCs, and increased polychromasia are common (sickle forms may be absent in transfused patients, patients with high hemoglobin F levels or in patients with phenotypes other than SCD-SS).
  • Reticulocyte count: Increased
  • Quantitative hemoglobin electrophoresis
  • Chemistry panel: Elevated lactate dehydrogenase (LDH), unconjugated bilirubin, aspartate aminotransferase (AST) (evidence of hemolysis)

Sickle Cell Disease - TREATMENT

Sickle Cell Disease - general measures

• Infection prophylaxis with penicillin starting by 2 months of age
• Pneumococcal vaccines (7-valent as per American Academy of Pediatrics [AAP] recommendations and 23-valent at 2 and 5 years of age)
• Meningococcal vaccines (Medimmune and Menactra) as per AAP recommendations
• Routine immunizations, including hepatitis B series; consider yearly influenza vaccine
• Consider folic acid supplementation
• Teach parents to monitor for fever, splenomegaly, pain (including dactylitis), increased jaundice
• Encourage good oral hydration and supply family with medications to treat uncomplicated painful episodes at home

Sickle Cell Disease - special therapy

• Transfusion therapy can prevent the development of SCD complications and decrease associated morbidity or recurrence of complications when used appropriately.
  • When children with SCD-SS receive erythrocyte transfusions, avoid posttransfusion hemoglobin levels >12 g/dL.
  • Erythrocyte antigen matching for ABO as well as C, D, E, and Kell is recommended.
  • Monitor children carefully for erythrocyte antibodies and/or delayed transfusion reactions.

Measures for specific complications:

• Fever (rule out sepsis):
  • History, physical examination, CBC, reticulocyte count, blood culture (urine culture, CSF culture, throat culture as indicated by examination)
  • Parenteral antibiotics to provide 24–48-hour coverage until blood cultures are negative
  • Close monitoring for other SCD complications
• Pain (vaso-occlusive episode):
  • Hydration: Avoid excessive hydration and encourage incentive spirometer use for acute chest syndrome prevention
  • Analgesics:
    • Patients and their families can often tell physicians what therapies have been helpful in the past.
    • In general, for mild pain, start with mild nonnarcotic medications (acetaminophen, ibuprofen) and mild oral narcotic analgesics (codeine, oxycodone).
    • Consider stronger agents such as oral ketorolac, hydromorphone, and morphine for initial management of moderate pain.
    • For severe pain, use parenteral medications such as morphine, hydromorphone, and ketorolac.
  • Comfort measures (massage, heating pad, warm soaks)
  • Frequent reassessment for pain control and side effects of medications is mandatory.
• Acute chest syndrome:
  • Initial findings: Chest tenderness, cough, hypoxia, fever, infiltrate on chest x-ray, leukocytosis, exacerbation of anemia
  • Parenteral antibiotics
  • Pain management
  • Supplemental oxygen for hypoxia
  • Incentive spirometry or chest physiotherapy
  • RBC cell transfusion for moderate to severe disease
• Splenic sequestration:
  • History, physical examination, CBC, reticulocyte count, blood culture as indicated, type, and screen
  • Initial findings: Increased spleen size, acute pallor, shock (if episode severe), anemia, thrombocytopenia, elevated reticulocyte count
  • Sequestration episode may have a more insidious onset or be chronic in nature
  • Fever management (if indicated)
  • Close, frequent observation of hemoglobin level, reticulocyte count, spleen size, and cardiovascular status
  • Fluid bolus and maintenance hydration
  • RBC transfusion: Avoid transfusing to hemoglobin values >10 g/dL, as hemoglobin may increase as the episode resolves and RBCs are released from the spleen.
  • Repeated sequestration episodes may be an indication for splenectomy.
• Transient aplastic episode:
  • History, physical examination, CBC, reticulocyte count (blood culture as indicated), type and screen, human parvovirus B19 serology
  • Initial findings: Pallor, tachycardia, absent or low reticulocytes unless recovery phase
  • Fever management (if indicated)
  • Close observation of hemoglobin level, reticulocyte count, and cardiovascular status
  • Respiratory isolation (95% of cases are due to infection with human parvovirus B19)
  • RBC transfusion for evidence of cardiovascular compromise
• Stroke (acute care):
  • History, physical examination, CBC, reticulocyte count, blood culture as indicated, type, and screen
  • Initial findings: Syncope, weakness, numbness, limpness, hemiparesis, seizure, headache, slurred speech, aphasia, somnolence, coma
  • Imaging: Head CT, brain MRI and MRA; consider arteriogram if aneurysm suspected
  • IV fluid bolus and maintenance hydration
  • Supplemental oxygen
  • RBC transfusion (given as simple or exchange transfusion)
  • Supportive (e.g., anticonvulsives)
• Stroke (primary and secondary stroke prevention), chronic care: Monthly RBC transfusions to keep HbS level <30%

Sickle Cell Disease - FOLLOW UP

Sickle Cell Disease - prognosis

Population estimates of life expectancy from 1978–1988 data range from 42–48 years for SCD-SS and from 60–68 years for SCD-SC. However, many believe that early SCD diagnosis (newborn screening), penicillin prophylaxis, comprehensive medical care, hydroxyurea therapy, and broader indications for chronic RBC transfusions (using chelation therapy or RBC exchange to treat transfusional iron overload) may increase life expectancy.

Sickle Cell Disease - complications

• Acute:
  • Painful episodes
  • Dactylitis: Painful swelling of hands and feet
  • Bacterial infection:
    • Streptococcus pneumoniae In young patients
    • Gram-negative organisms in older children and adults
    • Salmonella infections are problematic for patients of all ages.
  • Acute chest syndrome: A pneumonia-like illness defined as a new infiltrate on chest x-ray
  • Neurologic: Including stroke (infarctive and hemorrhagic) and transient ischemic attack
  • Acute splenic sequestration: Acute enlargement of the spleen, with a decreased hemoglobin and increased reticulocyte count
  • Aplastic episode: Transient decrease in RBC production characterized by a decrease in hemoglobin and reticulocyte count; human parvovirus B19 is most common cause
  • Cholecystitis: Risk is greatest after age 10 years.
  • Priapism: A prolonged penile erection, which can be seen in males of all ages
  • Hematuria
• Chronic:
  • Delayed linear growth and puberty
  • Cholelithiasis
  • Retinopathy: Particularly in children with SCD-SC
  • Neurologic: Sequelae of stroke, “silent” cerebral infarction, cerebral vasculopathy, and/or abnormal cerebral blood flow velocity
  • Hypersplenism: Particularly in young children or patients with SCD-SC or SCD-Sβ⁺ thalassemia
  • Avascular necrosis: Particularly of the hips
  • Pulmonary hypertension
  • Renal: Proteinuria, microalbuminuria, nephrotic syndrome, acute glomerulonephritis
  • Pulmonary function abnormalities
  • Primary nocturnal enuresis
  • Leg ulcers

Sickle Cell Disease - bibliography

Book Source Details

• Book Title: The 5-Minute Pediatric Consult
• Author(s): M. William Schwartz MD; et al.
• Year of Publication: 2008
• Copyright Details: The 5-Minute Pediatric Consult, Copyright © 2008 Lippincott Williams & Wilkins.

More About Sickle Cell Anemia

• Back to disease: Sickle Cell Anemia: Introduction
• Next Book Extract About Sickle Cell Anemia: Surveys relating to Sickle Cell Anemia
• More Book Extracts: All Online Books for Sickle Cell Anemia

More Medical Textbooks Online about Sickle Cell Anemia

Review other book chapters online related to Sickle Cell Anemia:

Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.

More About This Book: Title: The 5-Minute Pediatric Consult Authors: M. William Schwartz MD; et al. Publisher: Lippincott Williams & Wilkins Copyright: 2008 ISBN: 0-7817-7577-9

 » Next page: Surveys relating to Sickle Cell Anemia

Rate This Website

What do you think about the features of this website? Take our user survey and have your say:

Website User Survey

Medical Tools & Articles:

Next articles:

• Surveys relating to Sickle Cell Anemia
• Ask Question about Sickle Cell Anemia

Tools & Services:

• Bookmark this page
• Symptom Search
• Symptom Checker
• Medical Dictionary
• Give your feedback

Medical Articles:

• Disease & Treatments Search
• Misdiagnosis Center
• Full list of interesting articles

Forums & Message Boards

• Ask or answer a question at the Boards:
• I cannot get a diagnosis. Please help.
• Tell us your medical story.
• Share your misdiagnosis story.
• What is the best treatment for my condition?
• See all the Boards.

Enter your search terms Submit search form
Search The Web Search wrongdiagnosis.com

Common Health Mistakes

Symptom
Checker

Search Specialists by State and City