Friday, July 23, 2010

Acute Rheumatic Fever

  • Rheumatic fever Is a systematic disease characterized by inflammatory lesions of connective tissue and endothelial tissue, primarily affecting the heart and joints.
  • The pathogenesis is thought to be an autoimmune response to group A beta-hemolytic streptococcus.
  • There is cross-reactivity between cardiac tissue antigens and streptococcal cell wall components.
  • The unique pathologic lesions of rheumatic fever is the Aschoff body, a collection of reticuloendothelial cells surrounding a necrotic center on some structure of the heart.
  • Acute Rheumatic Fever is commonly seen in children ages 5 to 15 but may occur in adults.
  • There is a high recurrence rate, and 75% of those with ARF progresses to acute rheumatic heart disease in adulthood.
  • Complications include significant heart failure, pericarditis, pericardial effusions, aortic or mitral valve insufficiency, and permanent cardiac damage.
  1. History of streptococcal pharyngitis or upper respiratory infection 2 to 6 weeks before onset of illness.
  2. Jones criteria, presence of two major manifestations, or one major and two minor manifestations, plus evidence of preceding streptococcal infection, are required to establish diagnosis.
  3. Major manifestations:
    • Carditis
    • Polyarthritis
    • Chorea
    • Erythema marginatum
    • Subcutaneous nodules
  4. Minor manifestations:
    • History of previous rheumatic fever or evidence of pre-existing rheumatic disease.
    • Arthralgia: pain in one or more joints without evidence of inflammation, tenderness to touch, or limitation of motion.
    • Fever: temperature in excess of 100.4 degree Fahrenheit (38 degree Celsius).
    • Erythrocyte sedimentation rate (ESR) – elevated.
    • C – reactive protein – positive.
    • Electrocardiogram (ECG) changes – mainly pulse rate interval prolongation.
    • White blood cell count – elevated (leukocytosis).
Diagnostic Evaluation
  1. Throat culture for group A beta-hemolytic streptococci and blood sample for titter of streptococcal antibodies ( antistreptolysin O, or ASO titer) to support evidence of recent streptococcal infection.
  2. Complete blood count, ESR, and C-reactive protein for changes described above.
  3. Baseline ECG and echocardiogram may be done to evaluate valve function.
  4. Chest x-ray for cardiomegaly or heart failure.
Pharmacologic Interventions
  1. Antibiotics to treat streptococcal infection – generally I.M. penicillin or erythromycin in penicillin allergy.
  2. Corticosteroids for patients with carditis complicated by heart failure to prevent permanent cardiac damage.
  3. Salicylates or nonsteroidals for patients with arthritis (but not while on high-dose corticosteroids because of risk of GI bleeding) and antipyretics to control fever, after diagnosis has been established.
  4. Phenobarbital, diazepam if chorea is present.
  5. Prophylactic antibiotics for at least 5 years after ARF.
Nursing Interventions
  1. Monitor temperature frequently, and patient’s response to antipyretics.
  2. Monitor the patient’s pulse frequently, especially after activity to determine degree of cardiac compensation.
  3. Auscultate the hear periodically for development of new heart murmur or pericardial or pleural friction rub.
  4. Observe for adverse effects of salicylate or nonsteroidal anti-inflammatory drug (NSAID) therapy, such as stomach upset, tinnitus, headache, GI bleeding, and altered mental status.
  5. Monitor the patient’s response to long-term activity restriction.
  6. Restrict sodium and fluids and obtain daily weights as indicated.
  7. Administer medications punctually and at regular intervals to achieve constant therapeutic blood levels.
  8. Explain the need to rest (usually prescribed for 4 to 12 weeks, depending on the severity of the disease and health care provider’s preference) and assure the patient that bed rest will be imposed no longer than necessary.
  9. Assist the patient to resume activity very gradually once asymptomatic at rest and indicators of acute inflammation have become normal.
  10. Provide comfort measures.
  11. Provide safe, supportive environment for the child with chorea.
  12. Observe for the disappearance or any major or minor manifestations of the disease and report signs of increased rheumatic activity as salicylates or steroids are being tampered.
  13. Encourage continuous prophylactic antimicrobial therapy to prevent recurrence.

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