Deck 1 Flashcards
Q. What are the two main categories of lung disease? Name two diseases from each category.
A. Obstructive – reversible (asthma) and irreversible (COPD)
B. Restrictive – interstitial lung disease (fibrosing alveolitis) and chest cell disease (kyphoscoliosis)
Q. Name two clinical features of; a) asthma b) COPD c) bronchiectasis
A. Asthma –obstruction varies over time, FEV1/FVC ratio less than 80%, younger people? May be wheezing in response to; exertion, fumes, cold air
B. COPD – constant obstruction, FEV1/FVC ratio less than 80%, older smokers? Lung cancer?
C. Dilated bronchi which pool secretions, copious purulent sputum, may be a mix of restrictive and obstructive
Q. Name some mast cell mediators involved in asthma pathophysiology
A. Mast cells: granules, high affinity IgE. Mast cell may form crosslinks to allergens releasing histamine, granules fuse and other enzymes are released (+ve feedback)
B. Tryptase: enzyme involved in mast cell activation (measured for diagnosis)
C. Cytokkines TNF, IL-3/4/5
D. Eicosanoids
E. Histamine
- Q. Name two types of medication that can be used to treat asthma
A. Bronchodilators: beta-agonist, muscarinic antagonists, methylxanthines
B. Beta agonists: short acting (salbutamol, terbutaline), long acting (Salmeterol, formoterol), ultra-long (indacaterol used in USA)
C. Steroids
Q. How do beta agonists work in the lung
A. Lung: Beta-2-receptor is a G-protein-coupled receptor, beta agonists bind to the receptor resulting in a conformational change, this activates adenyl cyclase which converts ATP to C-AMP, the increased levels of C-AMP cause smooth muscles to relax (by activating kinase A and decreasing calcium levels)
Q. Name a short-acting and a long-acting muscarinic antagonist
A. Short acting: ipratropium
B. Long acting: tiotropium (has a high affinity so it dissociates slowly and has a longer affect)
C. Affects the intrinsic tone of airways (parasym – chorionic receptors)
D. Acetyl-coA contracts airway smooth muscles by activating muscarinic receptors – M3 (G-protein coupled)
E. Antagonists block ACh binding to muscarinic receptors
Q. What are the two main types of COPD?
A. Chronic bronchitis – inflammation of bronchi
B. Emphysema – damage to lung tissue and small airways, loss of elasticity
Q. What clinical features may be suggestive of lung cancer?
A. Airflow obstruction, low FEV1/FVC ratio, smoker, recent onset, over >40 years old
B. Change in cough, wheeze, haemoptysis (coughing up blood)
C. Later symptoms; weightloss, lethargy
Q. Name two clinical features of restrictive lung disease
A. Low lung volume – FVC
B. FEV1/FVC ratio > 80% as most of breath is out within the first second
Q. Name two clinical features of obstructive disease
A. History of wheezing/bronchitis, wheezing/hyperinflation on examination, obstructive spirometry, hyperinflated chest xray
Q. What is pulmonary vascular disease? Describe the three typical presentations
A. Pulmonary hypertension can lead to pulmonary embolism (clots in pulmonary arterial tree arising from deep veins in the legs)
B. Minor – breathlessness, haemoptysis, pleuritic chest pain
C. Acute massive – circulatory collapse, life-threatening emergency
D. Multiple/submassive – isolated dyspna, often missed
E. Often due to environment/occupation, pet allergy/asbestos/dust fume exposure
Q. Describe the following terms from a spirometry graph, give an estimated volume in mls for each. A) Tidal volume B) Functional residual capacity, C) Expiratory reserve volume, D) Inspiratory capacity, E) Total lung capacity, F) Vital capacity, G) Inspiratory reserve capacity
A. Tidal volume 500ml– The volume of air that enters and leaves the lungs during inspiration and expiration in normal breathing. (smallest value)
B. Functional residual capacity 2400ml – Amount of air remaining in the lungs at the end of normal breathing
C. Expiratory reserve volume 1200ml – The maximal additional volume of air that can be exhaled after a normal expiration to functional residual capacity, with residual volume remaining in the lungs
D. Inspiratory capacity 3500ml – The maximal volume of air that can be inhaled from functional residual capacity, this made of up tidal volume and inspiratory reserve volume
E. Total lung capacity 5900ml – This is the volume of air in the lungs after maximal inspiration
F. Vital capacity 4700ml – The maximal volume of air that can be exhaled from the lungs after a maximal inspiration
G. Inspiratory reserve capacity 3000ml – the amount of air in excess of tidal inspiration that can be inhaled with maximal effort
H. Residual volume 1200ml – The volume of air remaining in the lungs after maximal exhalation
Q. What is the transfer co-efficient? How is this lung function test carried out?
A. Measures the ability of oxygen to diffuse across the alveolar membrane
B. Patient inspires a low of carbon monoxide and holds breath from 10 seconds at total lung capacity, the gas transferred is then measured
Q. In which conditions may there be a low transfer co-efficient?
A. May be low in severe emphysema
B. Fibrosing alveolitis
C. Anaemia
D. (high in pulmonary haemorrhage)
Q. What other tests may be performed to test lung function?
A. 6 min walk, incremental shuttle walking test, Cardio-respiratory excersie test
B. lung function and transfer co-efficient test
