Cystic Fibrosis (CF)

  1. General information
    1. Disorder characterized by dysfunction of the exocrine glands (mucus-producing glands of the respiratory tract, GI tract, pancreas, sweat glands, salivary glands)
    2. Transmitted as an autosomal recessive trait
    3. Incidence: 1 in 1500-2000 live births
    4. Most common lethal genetic disease among Caucasians in U.S. and Europe
    5. No test to detect carriers
    6. Prenatal diagnosis of CF is not reliable
    7. Secretions from mucous glands are thick, causing obstruction and fibrosis of tissue
    8. Sweat and saliva have characteristic high levels of sodium chloride
    9. Affected organs
      1. Pancreas: 85% of CF clients have pancreatic involvement
        1. obstruction of pancreatic ducts and eventual fibrosis and atrophy of the pancreas leads to little or no release of enzymes (lipase [fats], amylase [starch], and trypsin [protein])
        2. absence of enzymes causes malabsorption of fats and proteins
        3. unabsorbed food fractions excreted in the stool produce steatorrhea
        4. loss of nutrients and inability to absorb fat-soluble vitamins causes failure to thrive
      2. Respiratory tract: 99.9% of CF clients have respiratory involvement
        1. increased production of secretions causes increased obstruction of airway, air trapping, and atelectasis
        2. pulmonary congestion leads to cor pulmonale
        3. eventually death occurs by drowning in own secretions
      3. Reproductive system
        1. males are sterile
        2. females can conceive, but increased mucus in vaginal tract makes conception more difficult
        3. pregnancy causes increased stress on respiratory system of mother
      4. Liver: one-third of clients have cirrhosis/portal hypertension
    10. The disease is ultimately fatal; average age at death is 20 years; 95% of deaths are from abnormal mucus secretion and fibrosis in the lungs
  2. Medical management
    1. Pancreatic involvement: aimed at promoting absorption of nutrients
      1. Diet modification
        1. infant: predigested formula
        2. older children: may require high-calorie, high-protein, or low/limited-fat diet, but many CF clients tolerate normal diet
      2. Pancreatic enzyme supplementation: enzyme capsules, tablets, or powders (Pancrease, Cotazym, Viokase) given with meals and snacks
    2. Respiratory involvement: goals are to maintain airway patency and to prevent lung infection
      1. Chest physiotherapy
      2. Antibiotics for infection
  3. Assessment findings: symptoms vary greatly in severity and extent
    1. Pancreatic involvement
      1. Growth failure; failure to thrive
      2. Stools are foul smelling, large, frequent, foamy, fatty (steatorrhea), contain undigested food
      3. Meconium ileus (meconium gets stuck in bowel due to lack of enzymes) in newborns
      4. Rectal prolapse is possible due to greasy stools
      5. Voracious appetite
      6. Characteristic protruding abdomen with atrophy of extremities and buttocks
      7. Symptoms associated with deficiencies in the fat-soluble vitamins
      8. Anemia
      9. Diagnostic tests
        1. trypsin decreased to absent in aspiration of duodenal contents
        2. fecal fat in stool specimen increased
    2. Respiratory involvement
      1. Signs of respiratory distress
      2. Barrel chest due to air trapping
      3. Clubbing of digits
      4. Decreased exercise tolerance due to distress
      5. Frequent productive cough
      6. Frequent pseudomonas infections
      7. Diagnostic tests
        1. chest x-ray reveals atelectasis, infiltrations, emphysemic changes
        2. pulmonary function studies abnormal
        3. ABGs show respiratory acidosis
    3. Electrolyte involvement
      1. Hyponatremia/heat exhaustion in hot weather
      2. Salty taste to sweat
      3. Diagnostic tests
        1. pilocarpine iontophoresis sweat test: indicates 2-5 times normal amount of sodium and chloride in the sweat
        2. fecal fat elevated
        3. fecal trypsin absent or decreased
  4. Nursing interventions
    1. Pancreatic involvement
      1. Administer pancreatic enzymes with meals as ordered: do not mix enzymes until ready to use them; best to mix in applesauce.
      2. Provide a high-calorie, high-carbohydrate (no empty-calorie foods), high-protein, normal-fat diet.
      3. Provide a double dose of multivitamins per day, especially fat-soluble vitamins (A, D, E, K), in water-soluble form.
      4. If low-fat diet required, MCT (medium-chain triglycerides) oil may be used.
    2. Respiratory involvement
      1. Administer antibiotics as ordered (all antibiotics for pseudomonas are given IV; doses may be above recommended levels (for virulent organisms)
      2. Administer expectorants, mucolytics (rarely used) as ordered.
      3. Avoid cough suppressants and antihistamines.
      4. Encourage breathing exercises.
      5. Provide percussion and postural drainage 4 times a day.
      6. Provide aerosol treatments as needed; hand-held nebulizers, mask, intermittent positive pressure breathing (IPPB), mist tent.
    3. Electrolyte involvement
      1. Add salt to all meals, especially in summer.
      2. Give salty snacks (pretzels).
    4. Provide appropriate long-term support to child and family.
    5. Provide client teaching and discharge planning concerning
      1. Genetic counseling
      2. Promotion of child's independence
      3. Avoidance of cigarette smoking in the house
      4. Availability of support groups/community agencies
      5. Alternative school education during extended hospitalization/home recovery