Respiratory (Week 8) Flashcards
Define ‘residual volume’ in terms of spirometry testing
Air in the lung which cannot be blown out
In relation to lung function, what term defines the measurement from being fully inspired to full expiration?
Vital capacity
What 2 results in reversibility testing spirometry suggest a diagnosis of asthma?
15% and 400ml reversibility in FEV1
What does an FEV1/FVC ration <70% indicate?
Obstructive disease
What FEV1/FVC ratio shows restrictive lung disease?
> 70%
Name three causes of hypoxaemia
Hypoventilation
Ventilation/perfusion mismatch
Shunting (e.g. congenital heart disease)
What PCO2 measurement would indicate type II respiratory failure?
PCO2>6
A PCO2 of <6 would indicate what?
Type I respiratory failure
Name 3 cell types associated with COPD?
CD8+ cells, macrophages and neutrophils
Which deficiency present in some COPD patients means they are unable to balance destructive enzymes in lungs?
Alpha 1 anti-trypsin deficiency
Define chronic bronchitis
Productive sputum most days for at least 3 months in at least 2 years
In chronic bronchitis, what causes loss of interstitial support in airways leading to inflammation?
Free radicals from neutrophils
Define emphysema
Permanent enlargement of airspaces distal to terminal bronchioles
Name 3 features of COPD on CXR
Hyperinflated lungs
Thin heart
Flattened hemi-diaphragm
Dark lungs
In COPD, what does <30% predicated FEV1 indicate?
Stage 4 (very severe) disease
Define pneumothorax
Air within pleural cavity causing collapse of elastic lung
Name three classifications of pneumothorax determined by cause
Traumatic
Iatrogenic
Spontaneous (primary/secondary)
If tension pneumothorax goes untreated, how does arrest occur?
Increased intra-pleural pressure leading to impaired venous return and BP fall
What measurement defines a ‘small’ pneumothorax
<2cm
Define talc pleurodesis in terms of pneumothorax management
Medicated talc applied to visceral pleura causes inflammatory response of adhesion of pleura to chest wall
Define the term allergy
Immune mediated intolerance of an external factor
Define the term intolerance
Inability to cope with normally acceptable conditions
What pathological mechanism causes a wheeze?
Turbulent airflow, a consequence of allergy
What two injectable agents can be effective in asthma management?
Anti-IL5 and anti-IL13
What disease is a result of allergy of the lung parenchyma caused by a trigger?
Extrinsic allergic alveolitis (EAA)
In EAA, chronic exposure to triggers can lead to which 2 lung complications?
Fibrosis (interstitial scarring) and emphysema
What fungus colonises keratinised areas?
Dermatophytes (ringworm)
Fungal meningitis is caused by which fungus?
Cryptococcus neoformans
Which fungal infection only occurs in immunocompromised patients?
Pneumocystis jiroveci
What is the mechanism of action of the anti-fungal Amphotericin B
Exploits ergosterol by forming pore in fungal membrane = cell death
What is the function of ergosterol?
An essential part of fungus plasma membranes
Why would IV magnesium be given in life threatening asthma exacerbations?
To relax smooth muscle and block histamine release from mast cells
What is the general MOA of corticosteroids?
Bind to glucocorticoid receptors to dampen pro-inflammatory genes by reversing histone acetylation
How do anti-muscarinic drugs work?
Antagonist of M1 and M3 cholinergic receptors in lungs to counteract direct bronchoconstriction
Give an example of
a) Short acting anti-muscarinic
b) Long-acting anti-muscarinic
a) Ipratropium bromide
b) Tiotropium
Briefly define the MOA of methylxanthines
Non-selective phosphodiesterase inhibitor which increases cAMP to cause bronchial SM relaxation
What is the function of the drug Carbocisteine in COPD?
Mucolytic to reduce sputum viscosity
What is the function of the drug Roflumilast in COPD?
Phosphodiesterase-4 selective inhibitor to reduce pro-inflammatory cytokines
Define pleural effusion
> 15ml fluid in pleural space
What usually causes transudate pleural effusions?
Excess fluid being pushed into pleura bilaterally with no extra cause e.g. due to heart failure
What usually causes exudate pleural effusions?
An additional causative pathology e.g. malignancy or empyema
In pleural effusion, what does grey fluid on ultrasound usually indicate?
Exudate pleural effusion due to excess protein in fluid appearing grey
In what circumstance should a pleural effusion NEVER be drained?
If the cause of the effusion is undiagnosed
What would you expect the pH and glucose levels to be in a para-pneumonic pleural effusion? (arises as a result of pneumonia)
pH <7.2
Glucose <2.2
What three symptoms occur in obstructive sleep apnoea?
- Upper airway obstruction during sleep
- Intermittent hypoxia
- Sleep fragmentation
Name three treatments of sleep apnoea
- Continuous positive airways pressure (CPAP)
- Mandibular advancement device
- Sleep position trainers
Name three non-metastatic effects of lung cancer
- Cushing’s (ACTH secreting tumour)
- SIADH (ADH secretion leading to water retention)
- Hypercalcaemia (parathyroid hormone related peptide secrtetion causing osteoclast activity)
Which type of lung cancer occurs in the periphery of the lungs and more commonly in women?
Adenocarcinoma
Which lung cancer type is the most aggressive and metastasises early in the disease process?
Small cell carcinoma
Define mesothelioma
Pleural tumour almost always caused by asbestos exposure
Define sarcoidosis
Multisystem inflammation of unknown cause, commonly affecting lungs and intrathoracic lymph nodes
Name 2 signs of Idiopathic pulmonary fibrosis
Bibasilar crackles
Subpleural honeycombing
Define pulmonary fibrosis
Scarring of the lungs with a specific cause such as smoking
Give an example of an occupational cause of pulmonary fibrosis
Asbestos exposure
Give two examples of a drug which can cause pulmonary fibrosis
Amiodarone
Methotrexate
Give two examples of diseases which can cause pulmonary fibrosis
Lupus
Rheumatoid arthritis
What imaging method is used to diagnose pulmonary fibrosis?
High resolution CT scan (HRCT)
