Flashcards in Resp Session 8 Deck (79):
What is the pathogenesis of interstitial lung disease (diffuse parenchymal lung disease)?
Start in intersticium --> surrounding structures involved --> acini, alveoli lumen, bronchioles lumen, bronchioles involved --> hypoxia and hypercapnia
How are ventilation, diffusion and perfusion affected in interstitial lung disease?
Ventilation decreased due to decreased compliance
Diffusion decreased due to barrier to gas exchange
Perfusion decreased due to damage/destruction of alveolar capillaries
What pattern on lung function tests is seen in interstitial lung disease?
What cells are involved in interstitial lung disease?
Recruited inflammatory cells
What is seen on CXR in interstitial lung disease?
Loss of silhouette sign
Increased reticular and nodular shadowing
What is seen on CT scan in interstitial lung disease?
Fibrosis visible as patchy white/grey areas
What is the classic Hx in interstitial lung disease?
Insidious onset with gradual decline SoB
What are the S/S of interstitial lung disease?
Progressive SoB on exertion +/- non-productive cough
Decreased chest movement
Signs of cor pulmonale
What are the 5 types of interstitial lung disease?
What can cause CT disease leading to interstitial lung disease?
At what age do immunological interstitial lung disease pts typically present?
20 or 60-70 y.o.
At what age does idiopathic pulmonary fibrosis typically present?
What is the problem with new therapies for idiopathic pulmonary fibrosis?
Slow mortality and decline in FVC but have significant drug toxicity
What effects can asbestos exposure have in the lungs?
Diffuse pleural thickening
Benign asbestos pleural effusions
Bronchogenic lung cancer
What is asbestosis?
Interstitial lung disease and asbestos exposure
How is sarcoidosis usually identified?
Incidentally as vast majority indolent
What is found on biopsy in sarcoidosis?
What are differentials for sarcoidosis following biopsy?
What are the Tx options for sarcoidosis?
Methotrexate (2nd line for steroid sparing)
How is pleural fluid in the reabsorbed in the pleural cavity?
Via stomata on parietal pleural surface --> lymphatic drainage
What can cause increased production of pleural fluid?
Increase in lung interstitial fluid
Hydrostatic pressure increases
Oncotic pressure decreases
Peritoneal fluid seeps through diaphragm
Thoracic duct disruption so no drainage
What can cause decreased absorption of pleural fluid?
Increased systemic venous pressures
What does Light's criteria state?
Pleural fluid is exudate if:
Pleural fluid protein/serum protein > 0.5
Pleural fluid or serum LDH > 0.6
Pleural fluid LDH > 2/3 upper normal lab limits
What are causes of transudate pleural effusion?
What are causes of exudate pleural effusion?
What can cause haemothorax?
Iatrogenic e.g. central line
What can cause chylothorax?
How does chylothorax appear?
What indicates empyema?
Decreased pH, decreased glucose and infection
CT and US show septations
What are risk factors for empyema?
What is the Tx of empyema?
Abx +/- drainage
What is the intersticium?
Potential space between alveolar membrane and capillary across which gas can move
What pts develop primary pneumothorax?
Otherwise healthy people, tend to be taller males
Which pts can develop secondary pneumothroax?
Those with underlying lung disease e.g. Cancer or COPD
What are the S/S of pneumothorax?
Pleuritic chest pain
Dyspnoea if large
What is iatrogenic pneumothorax?
Caused by procedures e.g. Central lines
How are small and large pneumothoracies differentiated on CXR?
What are the treatment options for pneumothorax?
Small, closed w/o significant SoB: observation, discharge and early review
If admittance for obs needed: high flow O2
Pts with SoB: simple aspiration
Recurrent cases: open thoracotomy and pleurectomy
What treatment option is available for pneumothorax pts who do not want surgery?
Chemical pleurodesis via surgical talk into drain to cause irritation of visceral and parietal pleura --> inflammation --> adhesion
How should a tension pneumothorax be diagnosed?
What are S/S of tension pneumothorax?
Decreased chest expansion with hyper resonance and absent breath sounds on one side
Mediastinal shift --> tracheal displacement and shift of apex beat
What is the Tx for tension pneumothorax?
Immediate cannula into affected side
Intercostal chest drain
Resp/thoracic surgical referral to prevent repeat
What congenital chest wall diseases can lead to hypoxia and hypercapnia?
What acquired chest wall diseases can lead to hypoxia and hypercapnia?
Motor neurone disease
What is a radiograph?
Electromagnetic wave of high energy and short wavelength passed through body --> different tissues absorb different amounts --> levels of contrast on grey scale
Why is CXR appropriate for almost all pts?
Low dose of radiation
What two different projections can be used for CXR?
PA projection (conventional, back to front)
When are AP CXR used?
For pts who are too unwell to stand
What are the potential problems with using AP CXR?
Lungs under inflated due to sitting position
Scapula over lung fields
What is checked for when assessing inclusion on a CXR?
Lateral margin of ribs
How is rotation assessed on CXR?
Spinous processes should be directly in the middle of medial ends of clavicles
Taken during inspiratory phase
At point of intersection of diaphragm and MCL should see 5-7 anterior ribs
How is lung volume assessed on CXR?
What on CXR indicates incomplete inspiration?
Big heart --> increased lung markings
What indicates exaggerated expansion caused by obstructive airway disease on CXR?
What effects lung volume filling on CXR?
Pt and radiographer factors e.g. explanation, inspiratory effort
How is penetration assessed on CXR?
Vertebrae should be just visible through heart and complete left hemidiaphragm should be visible
What can manipulate penetration on CXR if it is inadequate?
What is an artefact on CXR?
External/iatrogenic material that obstructs view e.g. Clothes, buttons, hair, surgical or vascular lines, pacemaker
Give 10 areas of thoracic anatomy which should be examined when assessing a CXR.
Hila - L should be higher than R
When might the nipples not show equally on CXR?
Penetration is not equal
Give a systematic approach to assessing a CXR.
Diaphragm and dem bones
List review areas in CXR where pathology is commonly missed.
Edge of films
What is the silhouette sign?
Adjacent structures of differing density give crisp silhouette and loss of this contour indicates pathology esp. consolidation
What causes mediastinal shift on CXR?
Push= increase in volume or pressure e.g. pleural effusion or tension pneumothroax
Pull= decreased volume or pressure e.g. lung collapse
What signs of pneumothorax are visible on CXR?
Visible pleural edge with no visible lung markings
What is visible on CXR in pleural effusion?
Uniform white area visible
Loss of costophrenic angle
Meniscus of fluid at upper border
What can cause lobar lung collapse?
Aspirated foreign material
Compression by adjacent mass
How does lobar lung collapse appear on CXR?
Raised epsilateral hemidiaphragm
Crowding of ipsilateral ribs
Shift of mediastinum due to atelectasis
Crowding of pulmonary vessels
Luftsichel sign in left upper lobe
How does consolidation appear on CXR?
Dense opacification +/- air bronchogram
What can cause consolidation in lung cancer?
What differentiates a nodule from a mass when assessing a SoL on CXR?
What causes SoLs?
Malignancy - primary will be single SoL, metastases often have multiple
Benign mass lesion
What can a SoL mimic on CXR?
What additional sign may be visible on CXR in SoL if phrenic diaphragm is implicated?
What should the cardiac index be on PA image?
What is indicated if the heart is the wrong way round on CXR with the apex on R?
What is indicated if heart is the wrong way round and liver and gastric bubble are on the opposite side to normal?
What are CT scans which give much more information than CXR not suitable for all pts?
Deliver much higher doses of radiation, esp if a contrast is used