Bronchiestasis, CF, Pneumonia Flashcards
What is bronchiectasis?
Disease with chronic and irreversible dilation of 1 or more bronchi so lungs cannot expel air properly. Inflammation permanently destroys elastic-like tissues and muscles surrounding bronchi.
Airflow obstruction and impaired clearance of secretions
What can bronchiectasis result in?
Poor mucus clearance so predisposition to bacteria
What can be seen on a chest scan for bronchiectasis?
- Dilated airways - Bronchus smaller than artery - Signet ring sign
Around 1/3 of cases of bronchiestasis in adults are associated with a severe lung infection in childhood. What are these childhood infections?
- Whooping cough 2. TB 3. Measles 4. Severe pneumonia
Some cases of bronchiestasis occur due to immunodeficiency. What are these immunodeficiencies?
- Common variable hypogammaglobulinaemia 2. Late onset idiopathic Ig deficiency 3. Selective immunoglobulin deficiency Immunodeficiency can be acquired after HIV
Some people with bronchiestasis develop ABPA. What is ABPA?
A complication of an allergic condition. People with ABPA have an allergy to a type of fungi known as aspergillus. If they breathe in fungal spores, it can trigger allergic reaction and persistent inflammation, which can progress to bronchiestasis
How can CF lead to bronchiestasis?
Mucus becomes clogged in lungs which is ideal environment for bacterial infection, leading to bronchiestasis
What is primary ciliary dyskinaesia (Kartagener’s)? How can it lead to bronchiestasis?
Problem with cilia due to inheriting faulty gene –> defective clearance of mucus
How can aspiration lead to bronchiestasis?
Stomach contents accidentally passes into lungs instead of down gastrointestinal tract –> inflammation and infection
What are the conditions that cause inflammation in other areas of the body that can be associated with bronchiestasis?
- Rheumatoid arthritis 2. Sjogren’s syndrome 3. Crohn’s disease 4. Ulcerative colitis 5. IBD 6. Coeliacs 7. Yellow nail syndrome 8. Alpha 1 antitrypsin deficiency
What are symptoms of bronchiestasis?
- Persistent purulent sputum (non smokers) - Haemoptysis - Breathless - Wheeze - Sinusitis and nasal symptoms - Weight loss - Pleurisy - Nasal polyps
What clinical signs are likely to be present on examination of bronchiestasis?
- Clubbing - Coarse crackles - Wheeze - None
What is clubbing?
Tissue at base of the nails is thickened and the normal angle between the base and adjacent ski is obliterated
What pathogens may cause an exacerbation of bronchiestasis?
- Staphylococcus aureus - Streptococcus pmeumoniae - Haemophilus influenzae - Pseudomonas aeruginosa - Aspergillus
What investigations should be taken for bronchiestasis?
- History - Genetics - Faecal elastase - Cilia beat frequency - Autoantibody screen - Sputum - Lung function - Aspergillus antibodies
Is bronchiestasis obstructive or restrictive?
Obstructive
What is cystic fibrosis?
Inherited (autosomal recessive) condition that causes sticky mucus to build up in lungs and digestive system. Lungs get increasingly damaged over time (cysts and fibrosis)
How common is CF?
Carrier frequency of 1 in 25 CF incidence 1 2000-2500 More than 2000 mutations
What is CF caused by?
Mutation in gene CFTR (found on chromosome 7) Most common mutation is Phe508del (deletion of 3 nucleotides that results in loss of phenylalanine at 508th position on protein). F508 deletion.
Ciliated airway epithelial cells in patient have mutated protein which leads to airway dehydration and abnormally viscous mucus production.
What are symptoms of CF?
- Repeated chest infections - Wheezing, coughing, shortness of breath, damage to airways (bronchiestasis) - Jaundice - Diarrhoea, constipation - Difficulty putting on weight and growing (don’t absorb nutrients properly as mucus clogs pancreas)
- Haemoptysis
- Reduced vision
What else can CF lead to?
- Diabetes (over 30% of adults have CF related diabetes) - Osteoporosis - Infertility in males - Liver disease
What is the product of the CFTR protein?
A chloride ion channel important in creating sweat, digestive juices and mucus
- Facilitates movement of chloride from swaet fuct into cytoplasm
What does mutation in CFTR result in?
Excess chlorine in sweat which prevents sodium reabsorption by epithelial sodium channels and the combination of Na and Cl creates the salt which is lost in high amounts in sweat –> lost salt forms basis of sweat test
Water follows Na so depth of airway lining fluid will be depleted (airway dehydration) and cilia will be left in the mucous layer
Gene is required to regulate the hydration of sweat, digestive juices, airways and mucus
How can CF be diagnosed?
- Pancreatic function –> faecal elastase
- CT chesst, US liver and pancreas
- Sperm (obtructive azoospermia)
Is CF obstructive or restrictive?
Obstructive
What is the average survival age of those with CF?
Around 35-40
How can CF be diagnosed?
- Newborn babies are screened
- Sweat test (measure salt which will be high in CF)
- Genetic test (check for faulty gene)
What are chances of child having CF if both parents are carriers?
1/4 their child will be normal
1/2 their child will inherit faulty gene from one parent and be a carrier
1/4 their child will inherit faulty gene from both parents and have CF