Chest Medicine (week 6) Flashcards
(128 cards)
Name 3 chest pathologies that affect the airways?
COPD
Asthma
Bronchiectasis
Name 3 chest pathologies that affect the Interstitium/parenchyma?
Pulmonary fibrosis
Hypersensitive pneumonitis
(emphysema)
Name 3 chest pathologies that affect the pleura?
Pleural effusion
Pleural maliganancy
Pleural thickening
Name 3 chest pathologies that affect the vasculature?
PE
Pulmonary HTN
Name 4 chest pathologies that affect the lungs ventilation?
Sleep disordered breathing
Obesity hypoventilation
Neuromuscular disease
Thoracic cage abnormalities
What parameters are tested in spirometry?
FEV1 (forced expiratory volume in 1 SEC)
VC (vital capacity)
FVC (forced vital capacity - how much total air)
What is the significance of FEV1/VC ratio?
FEV1/VC ratio <70% = obstructive
FEV1/VC ratio normal = restrictive
What is the FEV1/VC ratio of obstructive disease? Give 3 examples of obstructive pathologies.
FEV1/VC ratio <70% = obstructive
COPD, Asthma, Bronchiectasis
What is the FEV1/VC ratio of restrictive disease? Give 4 examples of restrictive pathologies.
FEV1/VC ratio normal = restrictive Pulmonary Fibrosis Hypersensitivity pneumonitis Neuromuscular disorders Thoracic cage abnormalities
What are the 3 pulmonary function tests?
Spirometry, Lung Volumes (flow volume loop), Transfer Factor
What is the characteristic flow volume loop shape of large airway obstruction?
Hamburger shape
What is the characteristic flow volume loop shape of small airway obstruction?
(COPD) Church and steeple
What are the 2 main measurements of lung volumes?
TLC (total lung capacity)
RV (residual volume)
What patterns of lung volumes are seen in an obstructive pathology?
TLC increases with hyperventialtion
RV increases with gas trapping
What patterns of lung volumes are seen in an Restrictive pathology?
TLC falls (definition of restriction) RV falls but proportionally the same
What are the 2 parameters of transfer factor that we measure?
TLCO (transfer factor of CO)
KCO (coefficient of CO) - per unit volume
What is transfer factor a measurement of?
Functionality of the alveolar-capillary membrane
What factors affect the TLCO? Which conditions are these seen in?
- Ventilation Perfusion Mismatch - common in many lung diseases
- Reduction in the area of alveolar-capillary membrane - e.g. emphysema
- Increased thickness of alveolar-capillary membrane - e.g. pulmonary fibrosis
- Pulmonary Blood flow - e.g. pulmonary hypertension
- Haemoglobin concentration - e.g. anaemia leads to a decrease in TLCO
How do we use TLCO and KCO in unison?
KCO is a useful measurement to give information on functionality ‘per unit volume’ of lung
- I.e. 2 full functioning lungs TLCO = 100%, KCO = 100%.
But in someone with a pneumonectomy (1 lung)
- TLCO = 50% but KCO would be 100%.
What is the TLCO & KCO pattern for the obstructive pathologies (asthma and COPD)?
Asthma - TLCO = normal, KCO = normal
COPD - TLCO = decreased, KCO = decreased
What is the TLCO & KCO pattern for restrictive pathologies, both intrapulmonary (IPF) and extrapulmonary (obesity)?
Intrapulmonary (IPF) - TLCO = decreased, KCO = decreased
Extra-pulmonary (obesity) - TLCO = decreased, KCO = Increased (to keep up with demand)
What are the differentials of a diffusely abnormal CXR?
Cardiac failure/ pulmonary oedema Pneumonia/ ARDS Idiopathic pulmonary fibrosis (IIPs) Sarcoidosis Pneumoconiosis Hypersensitivity pneumonitis
What is the difference between HRCT and spiral/helical CT? When is it appropriate to use each?
HRCT
- Finely detailed pictures of parts of the lung e.g. 1mm slice every 10mm
- Good if suspect diffuse condition [fibrosis; HP; bronchiectasis]
Spiral or Helical
- Less detailed imaging but done in continuum therefore do not miss small nodules etc
What is pneumoconiosis?
Lung disease caused by mineral dust