Cystic Fibrosis Flashcards
What are the genetics and presenting features of cystic fibrosis?
Genetics: Cystic fibrosis (CF) is caused by mutations in the CFTR gene (Cystic Fibrosis Transmembrane Conductance Regulator) on chromosome 7, leading to defective chloride ion transport across epithelial cells.
Presenting features include:
Chronic cough with sputum production.
Wheezing and shortness of breath (due to lung involvement).
Salty-tasting skin.
Failure to thrive and malabsorption (due to pancreatic insufficiency).
Infertility (in men, typically due to absence of the vas deferens).
Recurrent respiratory infections.
What are the possible complications of cystic fibrosis?
Respiratory complications: Chronic lung infections (e.g., Pseudomonas aeruginosa), bronchiectasis, respiratory failure.
Gastrointestinal complications: Pancreatic insufficiency, malnutrition, vitamin deficiencies, liver disease.
Reproductive issues: Infertility (most men are infertile).
Endocrine issues: CF-related diabetes.
Osteoporosis due to malnutrition and steroid use.
Sinusitis and nasal polyps.
Cor pulmonale (right-sided heart failure due to chronic lung disease).
How is pancreatic insufficiency and chest infection managed in cystic fibrosis?
Pancreatic insufficiency:
Pancreatic enzyme replacement therapy (PERT) to aid digestion.
Vitamin supplementation (A, D, E, K) to address deficiencies.
High-calorie, high-fat diet to improve nutrition.
Chest infection:
Antibiotics (oral, intravenous, or inhaled) to treat bacterial infections.
Bronchodilators and mucolytics (e.g., dornase alfa) to improve airflow and reduce mucus viscosity.
Chest physiotherapy to help clear mucus from the lungs.
Oxygen therapy for hypoxemia if needed.
What are the options for antenatal and postnatal screening for cystic fibrosis?
Antenatal screening:
Carrier screening for cystic fibrosis (CFTR gene mutation test) can be done for parents.
Chorionic villus sampling (CVS) or amniocentesis for diagnosing CF in the fetus if both parents are carriers.
Postnatal screening:
Newborn screening involves testing for elevated immunoreactive trypsinogen (IRT) levels in blood, followed by DNA testing for CFTR mutations if IRT levels are high.
Sweat chloride test is the gold standard diagnostic test for cystic fibrosis.
What are the differing issues associated with the management of adult and paediatric patients with cystic fibrosis?
Paediatric management:
Focus on growth and development.
Emphasis on nutritional support and pancreatic enzyme replacement.
Managing frequent respiratory infections and improving airway clearance.
Parental education and support.
Adult management:
Managing chronic respiratory decline and complications like pulmonary fibrosis.
Transitioning to adult CF care centers.
Focus on reproductive health, CF-related diabetes, and end-of-life care.
Psychosocial support due to chronic disease burden.
What is the social, educational, and economic impact of cystic fibrosis on the child and family?
Social impact: Social isolation due to frequent hospitalizations, limitations on physical activity, and concerns about cross-contamination with other CF patients.
Educational impact: Frequent school absences, need for special accommodations, and potential learning difficulties related to illness.
Economic impact: High healthcare costs (medications, hospitalizations, therapies), parental work limitations, and the financial burden of long-term care and medical treatments.
What is the role of transplantation in cystic fibrosis?
Lung transplantation: Can be a life-saving treatment for patients with end-stage lung disease and respiratory failure.
Pancreatic transplantation: Considered for patients with severe pancreatic insufficiency and diabetes that are difficult to manage.
Heart-lung transplantation: In patients with advanced CF-related heart and lung failure.
What are the end-of-life issues associated with cystic fibrosis?
Respiratory failure: Progressive lung disease can lead to end-stage respiratory failure, requiring palliative care.
Decision-making: Discussions around ventilator support, organ transplantation, and comfort care options.
Psychological support for patients and families dealing with terminal illness.
Advance care planning and ensuring patient wishes are respected in the end stages.
What are emerging CFTR modulator therapies for cystic fibrosis?
CFTR modulator therapies aim to correct the underlying defect in the CFTR protein, improving its function.
Ivacaftor: A potentiator that enhances the function of the CFTR protein in certain mutations.
Lumacaftor and tezacaftor: Correctors that help the CFTR protein fold correctly and reach the cell surface.
Elexacaftor-tezacaftor-ivacaftor (Trikafta): A combination therapy for patients with at least one F508del mutation, significantly improving lung function and quality of life.
These therapies have shown promising results in improving lung function, reducing pulmonary exacerbations, and improving overall health outcomes in eligible patients.
