Cystic fibrosis

Background

  • Autosomal recessive genetic disorder
    • Due to a mutation in cystic fibrosis transmembrane conductance regulator protein (CTFR)
    • CTFR=chloride channel important in function of mucus, sweat, and digestive fluids.
  • Causes thick, viscous mucus leading to obstruction, inflammation, and damage to respiratory tract and exocrine organs
  • Diagnosed by "sweat test" and/or genetic test

Clinical Features

  • Respiratory
    • Acute exacerbations lead to increase in baseline cough and sputum production
    • Pneumonia
    • Increased risk of pneumothorax (8%–20% will develop one in lifetime[1])
    • Bronchitis
    • Sinusitis, nasal polyps
    • Chronic inflamation/infection leads to bronchiectasis and angiogenesis, which may lead to hemoptysis
    • Long-standing disease can eventually lead to cor pulmonale
  • Gastrointestinal
    • Pancreatic insufficiency
    • Pancreatitis
    • Diarrhea and malnutrition due to resultant malabsorption
    • Meconium ileus: failure to pass meconium within first 48 hours of life
      • Obstruction due to thick meconium
      • Can lead to perforation if unrecognized
  • 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

  • CBC (signs of infection), electrolytes, LFTs/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

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

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