Cystic Fibrosis🫁

Overview of Cystic Fibrosis (CF)

  • Cystic fibrosis is a genetic disorder affecting 1 in 3600 children in Canada.
  • It can be detected prenatally for at-risk couples and through newborn screening with blood and urine tests.

Genetic Aspect

  • CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) acts as a channel for chloride ions.
  • Disruption of chloride ion transport results in altered water flow, leading to increased viscosity of secretions throughout the body.

Carrier Frequency

  • Approximately 1 in 25 individuals in Canada are carriers of the CF gene.
  • The carrier rate increases to 1 in 20 for Quebecois.

Pathophysiology of Cystic Fibrosis

  • Sweat glands excrete excessive chloride leading to:
    • Electrolyte imbalances.
    • Dehydration symptoms.
  • Salty forehead on kissing a baby is an indication of cystic fibrosis.
Effects on Pancreas and Mucus Secretion
  • Blockage of pancreatic canals prevents secretion of enzymes necessary for fat and protein digestion.
  • Nutrient malabsorption results in poor growth and floating stools due to fats in stool.
  • Accumulation of thick mucus in tracheobronchial glands results in:
    • Frequent coughing.
    • Trapped air in smaller airways causing atelectasis.
    • Increased risk of bacterial infections and respiratory failure.
Common Associated Conditions
  • Nasal polyps and recurrent sinusitis.
  • Male infertility due to thick seminal fluid; female infertility due to thick cervical mucus.

Diagnosis

  • CF can be diagnosed in early childhood (within first 6 months) or in adulthood when symptoms are subtle.
  • Signs and symptoms include:
    • Salty sweat.
    • Repeated respiratory infections.
    • Failure to thrive.
    • Floating stools.
  • Examination includes:
    • General appearance.
    • Work of breathing (WOB).
    • Cough and sputum analysis.
    • Clubbing of fingers and toes.
    • Height assessment.
Diagnostic Tests
  • Sweat chloride test.
  • Chest X-ray.
  • Pulmonary function test.
  • Blood tests (including vitamin and pancreatic enzyme levels).
  • Fecal analysis for enzymes and fats.

Management Goals

  • Maximize lung function.
  • Liquefy secretions to decrease complications and bacterial infections.
  • Daily chest physiotherapy to mobilize secretions.
  • Techniques for secretion clearance include:
    • Postural drainage.
    • Percussion.
    • Vibration.
    • Positive expiratory pressure (PEP) masks.
    • Autogenic drainage (for older children).

Therapeutic Management

  • Physical Exercise to promote overall health.
  • Medications:
    • Bronchodilators (e.g., Ventolin).
    • Corticosteroids (e.g., Flovent).
    • Antibiotics.
    • Mucolytics (e.g., Pulmozyme), which reduce mucus viscosity by degrading DNA and its components.
    • Side effects of Pulmozyme can include voice changes and rashes.
  • Nasal Corticosteroids and Acetylcysteine (also known as a respiratory mucolytic):
    • It attracts water towards mucus, thinning it.
    • Hypertonic saline also increases salt in airways to attract water and thin mucus.
    • Potential side effects include increased cough and sore throat.

Nutritional Considerations

  • Recommended supplements include vitamins A, D, E, K, iron, zinc, and laxatives.
  • Encourage intake of salty foods to help manage electrolyte balance.

Conclusion

  • Cystic fibrosis is not curable but is treatable with proper management strategies, aimed at increasing growth, improving quality of life, and minimizing complications.