Respiratory Flashcards
What are the main classes of drugs used to treat respiratory disease?
inhaled corticosteroids
bronchodilators
What kind of drugs end in “…mab”?
monoclonal antibodies
What kind of drugs end in “…sone”?
corticosteroids
What kind of drugs end in “…lone”?
corticosteroids
What kind of drugs end in “…terol”?
bronchodilators
What kind of drugs end in “…nib”?
kinase inhibitors
What are the advantaged for inhaled medicines?
lungs are robust
large surface area for absorption
rapid absorption
fewer drug metabolising enzymes
fewer systemic side effects
What lung diseases are associated with bronchoconstriction?
Asthma
COPD
How does bronchoconstriction differ between asthma and COPD?
it is mostly irreversible in asthma and much less reversible in COPD
What are the categories of bronchodilator drugs?
adrenergic (sympathetic)
causes bronchodilation
anti-cholinergic (parasympathetic)
blocks bronchoconstriction
What is another name for adrenergic bronchodilators?
beta 2 adrenergic agonists
What diseases are associated with respiratory inflammation?
pneumonia
asthma
COPD
IPF (idiopathic pulmonary fibrosis)
How do you decide what drugs to use to treat respiratory inflammation?
determine whether it’s chronic or acute exacerbate inflammation and treat based on that
What class of drugs are used to treat respiratory inflammation?
glucocorticoids (inhaled corticosteroids: ICS)
What is a limitation of treated respiratory inflammation with glucocorticoids?
only really effective for asthma, relatively ineffective in COPD, CF, IPF
people with severe asthma can become resistant
What are the side effects of ICS?
loss of bone density
adrenal suppression
cataracts, glaucoma
What is the pleura?
lining of the lung
Describe the basic anatomy of the pleura.
2 layers:
visceral pleura- forms outer covering of lung
parietal pleura- forms inner lining of chest wall
between the 2 layers in the pleural space which contains about 5-10mls of fluid
What is the purpose of the pleura?
allows optimal expansion and contraction of lungs
pleural fluid and visceral and parietal pleurae to glide over with friction during respiration
What is a pneumothorax?
‘collapsed lung’
presence off air in the pleural space
What causes a pneumothorax?
air enters the lungs due to:
- hole in lung/ pleura
- chest wall injury
intra pleural pressure is negative, which leads to air being sucked into cavity
What are the classifications of pneumothorax?
- primary spontaneous
- secondary spontaneous
- traumatic
- iatrogenic
What is a primary spontaneous pneumothorax?
collapsed lung with no underlying lung disease
rupture of apical pleural bleb
What are the risk factors for a primary spontaneous pneumothorax?
male
smoker
tall
age 20-40 y/o
What is secondary spontaneous pneumothorax?
collapsed lung in presence of known lung disease
What type of lung disease causes secondary spontaneous pneumothorax?
60% COPD
asthma/ ILD/ CF/ lung cancer
cystic lung disease
also…
Infection:
- PCP/ TB
- lung abscess
Genetic predisposition:
- Marfan’s syndrome, Birt-Hogg Dube
- LAM (lymphangioleiomyomatosis)
Catamenial pneumothorax
What is a traumatic pneumothorax?
penetrating chest wall injury
may be a puncture from a rib
may also rupture bronchus/ oesophagus
What is iatrogenic pneumothorax?
‘doctor induced’ collapsed lung
risks include:
- pacemakers
- CT lung biopsies
- central line insertion
- mechanic ventilation
- pleural aspiration
How does pneumothorax present?
asymptomatic
acute/ sudden
breathlessness
pleuritic chest pain
cough
What is the worst possible complication of pneumothorax?
life threatening respiratory failure/ cardiac arrest
What are the symptoms of lung cancer?
LOCAL:
- increasing shortness of breath
- continuous cough for more than 3 weeks
- haemoptysis
- recurrent chest infections
GENERALISED/ SYSTEMIC:
- general malaise
- weight loss
- paraneoplastic syndrome
What type of cancer are most lung tumours?
90% are carcinomas
others include:
- benign tumours
- salivary gland tumours
- soft tissue tumours (sarcomas)
- lymphoma
What is the classification of lung carcinomas?
non-small cell lung carcinoma (NSCLC)
small cell lung carcinoma (SCLC)
How is non-small cell lung cancer treated?
resection +/- chemotherapy
What % of lung carcinomas are non-small cell?
85%
What are the 3 main types of non-small cell lung carcinoma?
adenocarcinoma
squamous cell carcinoma
large cell carcinoma
How do you differentiate between types of non-small cell carcinomas?
can only really differentiate from the histology
What risk factor is most associated with small cell carcinoma?
cigarette smoking
What is ILD?
interstitial lung disease
What is an example of restrictive lung disease?
emphysema
interstitial lung disease
How can interstitial lung diseases be physiologically measured?
- restriction of lung volumes (measured by FVC)
- reduction in lung gas transfer efficiency (DLCO/ TLCO)
- hypoxia, particularly on exertion
- reduction in exercise capacity
Why is not possible to lump all ILDs together?
because treatment varies massively depending on the type of ILD
Describe the pathophysiology of idiopathic pulmonary fibrosis.
- fibroblasts repair damaged tissue
- fibroblasts migrate to the lungs and become myofibroblasts
- myofibroblasts deposit collagen in the extracellular matrix
- In IPF, these fibroblasts are resistant to apoptosis (cell death)
- my-fibroblasts proliferate and form fibroblastic foci
- the thickened tissue leads to lower gas exchange efficiency in the lungs
What are the key features of idiopathic pulmonary fibrosis?
- collections of fibroblasts
- thickening of alveolar interstitium
- destruction (honeycombing) of alveoli
- affects periphery and base of lungs
- spatial heterogeneity (normal lung tissue next to abnormal tissue)
How is IPF treated?
pirfenidone and nintedanib
What are the main side effects of pirfenidone?
photosensitivity (skin rash)
gastrointestinal upset
How does pirfenidone affect the progression of IPF?
does not improve the condition, patients will still worsen but the decline won’t be as steep
What is the main side effect of nintedanib?
diarrhoea
What is the mechanism of action of nintedanib?
inhibitor or multiple tyrosine kinase receptors
interferes with processes such as fibroblast proliferation, migration and differentiation and secretion of extracellular matrix (collagen)
Can nintedanib improve IPF?
no- same as pirfenidone in that sense, won’t reverse any damage but will slow down deterioration
What is hypersensitivity pneumonitis?
also called extrinsic allergic alveolitis
inflammation of the lungs as part of an allergic reaction
What type of reaction is hypersensitivity pneumonitis?
type III hypersensitivity reaction
What is the typical presentation of TB?
lung infection, productive cough, blood in the sputum
What vaccine protects against TB?
BCG vaccine
What is the leading killer of people with HIV?
TB
What does “smear positive” mean in TB?
if there is enough bacteria in the sputum to see the bacterium under the microscope
How do acquire TB if not from other people?
drinking unpasteurised cows milk- cows can be infected with m.bovis which can give humans TB of the gut
What is the historical name for TB?
consumption
What is the classic x-ray sign of TB?
cavity in apex of lung (white ring at top of lung)
