Cystic fibrosis

(Redirected from Cystic Fibrosis)

Background

  • Autosomal recessive genetic disorder
    • Mutation in cystic fibrosis transmembrane conductance regulator protein (CTFR) leads to defect of sodium/chloride exchange channel
    • Defect in chloride transport leads to thick, viscous secretions in lungs, pancreas, liver, intestines, reproductive tract
  • Diagnosed by sweat chloride test
  • Predicted life expectancy less than 40 years

Clinical Features

  • Respiratory
  • Gastrointestinal
    • Meconium ileus: failure to pass meconium within first 48 hours of life
      • Earliest clinical manifestation of disease
      • Occurs in 10 - 20% of those diagnosed
      • 90% of babies with meconium ileus have cystic fibrosis
      • Obstruction due to thick meconium
      • Can lead to perforation if unrecognized
      • Diagnosed and treated with hyperosmolar contrast enema
    • Pancreatic insufficiency
      • Often leads to failure to thrive in infant
    • Pancreatitis
    • Diarrhea and malnutrition due to resultant malabsorption
  • Other
    • Electrolyte disturbances
    • Suppurative parotitis
      • Rapid onset parotitis (warm, swollen, tender gland, fever, trismus)
      • Purulent drainage from Stensen's duct
      • Organisms: staph, strep pneumo, strep pyogenes, H. flu, e. coli, pseudomonas

Differential Diagnosis

Evaluation

  • Sweat chloride test to make diagnosis
  • May also be diagnosed by amniocentesis if high suspicion antenatally
  • CBC (signs of infection)
  • Electrolytes
  • Liver function tests and lipase (if concern for pancreatitis)
  • Consider blood and sputum cultures (may have resistant organisms)
  • CXR
    • Advanced disease: peribronchial thickening, mucous plugs, cystic/bullous lesions, atelectasis, hilar adenopathy, air trapping
    • Infiltrates if pneumonia
    • Pneumothorax

Short-Term Management

  • Infections
  • Other respiratory adjuncts
    • Albuterol or other short-acting Beta-2 agonist
    • Dornase alfa (inhaled recombinant deoxyribonuclease I, hydrolizes DNA in sputum to decrease viscosity)
    • Nebulized Hypertonic saline (reduce sputum viscosity)
    • Inhaled nitric oxide
    • Chest physical therapy
  • See treatment for pancreatitis
  • Rehydrate if volume depleted, replete electrolytes
  • Note potential for hypoalbuminemia when giving extensively protein-bound drugs

Long-Term Management

  • Chest physiotherapy
  • Exercise therapy
  • Pancreatic enzymes
  • Fat-soluble vitamin supplementation
  • Nebulised DNase
  • Lung transplant

Disposition

  • Dispo decision should be made in conjunction with patient's pulmonologist if possible, as they often know their patients very well

See Also

External Links

References

  1. Tintanelli's

Authors:

Claire