10 Flashcards
(42 cards)
1
Q
What do you need to see in a CXR?
A
- 1st rib
- lateral margin of ribs
- costaphrenic angle
Alignment of: spinous processes and clavicles
See lecture 10.1 slide 6-7
2
Q
In terms of lung volume, what must you look at in a CXR?
A
- at inspiratory phase: 5th to 7th ribs are normally at MCL
- problems with incomplete inspiration will show a big heart and increased lung markings
- exaggerated expansion shows obstructive airways disease
See lecture 10.1 slide 8-9
3
Q
What is penetration in terms of CXR?
A
- degree to which the xrays have passed through the body
- adequate penetration: vertebrae just visible through heart, complete left hemidiaphragm is visible
See lecture 10.1 slide 10-15
4
Q
How would you evaluate a CXR?
A
-ABCD approach
-patient demographics, projection, adequacy
Airway
Breathing
Circulation
Diaphragm/Dem Bones
See lecture 10.1 slide 16
5
Q
Explain adequacy
A
RIP
Rotation, inspiration, penetration
See lecture 10.1 slide 17
6
Q
Explain airway in CXR
A
-look at trachea and bronchi
See lecture 10.1 slide 18
7
Q
Explain breathing in CXR
A
- compare same zones to each other
- look around at all pleural spaces and edges
- silhouette sign
See lecture 10.1 slide 19
8
Q
Explain circulation in CXR
A
Look at:
- mediastinum
- aortic arch
- pulmonary vessels
- right heart border
- left heart border
See lecture 10.1 slide 20
9
Q
Explain diaphragm/dem bones in CXR
A
- look for free gas under diaphragm
- nodules
- fracture/dislocation
- mass
See lecture 10.1 slide 21
10
Q
What areas in a CXR do people commonly miss pathology?
A
- spices
- thoracic inlet
- paratracheal stripe
- AP window
- hila
- behind heart
- below diaphragm
- bones (all of them)
- edge of films
See lecture 10.1 slide 22-32
11
Q
What is the silhouette sign?
A
- adjacent structures of DIFFERING DENSITY form a CRIsP SILHOUETTE
- ex: heart next to lung shows white next to black
- loss of contour can locate pathology
If you lose…you get pathology in….
- right heart border, RML
- left heart border, lingula
- paratracheal stripe, mediastinal disease
- chest wall, lung/pleura/rib
- aortic knuckle, anterior mediastinum/upper lobe
- diaphragm, lower lobe
- horizontal fissure, anterior segment upper lobe
See lecture 10.1 slides 33-36
12
Q
What is mediastinal shift
A
- usually mediastinum is centred
- look at trachea and cardiac shadow
- see if mediastinum is pushed or pulled
- push: increase volume or pressure
- pull: decrease volume or pressure
See lecture 10.1 slides 37-39
13
Q
What descriptive terms should you use when describing a CXR?
A
- tissue involved
- size
- side
- number
- distribution
- position
- shape
- edge
- pattern
- density
See lecture 10.1 slide 41
14
Q
What is a pneumothorax?
A
- air trapped in pleural space
- can be primary or secondary
- most common cause is trauma
- lung edge measures >2cm from the inner chest wall at the level of the hilum
- mediastinal shift away from pneumothorax and depressed hemidiahragm means pneumothorax is under tension
- signs: visible pleural edge, lung markings not visible beyond this edge
- lung collapses due to unopposed elastic recoil
See lecture 10.1 slides 43-46, and 2019 pneumothorax slide3-4
15
Q
What is a lobar lung collapse?
A
- volume loss within lung lobe
- causes: luminal, mural, extrinsic
- generic findings: elevation of ipsilateral hemidiaphragm, crowding of the ipsilateral ribs, crowding of pulmonary vessels
See lecture 10.1 slide 47-49
16
Q
What is consolidation?
A
- filling of small airways/alveoli with STUFF
- dense opacification
- volume preserved or increased
- air bronchogram
See lecture 10.1 slide 50-52
17
Q
What is a space occupying lesion (SOL)?
A
- could be a nodule (<3cm) or a mass (>3cm)
- single vs. Multiple
- causes: malignant, benign mass lesion, inflammatory, congenital, mimics
See lecture 10.1 slide 53-55
18
Q
What is the cardiac index?
A
- ratio between size of heart and size of thoracic cavity
- should normally be <50% and done on a PA image
See lecture 10.1 slide 56-57
19
Q
Other than a CXR, what other investigations can be done?
A
- CT
- angiogram
- ultrasound
- nuclear medicine
See lecture 10.1 slide 58-75
20
Q
Where does the air in a pneumothorax come from?
A
The lung (commonest by far)
- primary spontaneous (no underlying cause)
- secondary to underlying lung disease or trauma
- iatrogenic: high pressure ventilation, central line placement
Through the chest wall (rare)
- trauma
- iatrogenic
Both the lung and through the chest wall (rare)
-trauma (ex. Stabbing)
See 2019 pneumothorax slide 5
21
Q
What is a primary spontaneous pneumothorax?
A
- most commonly in young, tall, thin males
- no lung disease or thoracic trauma
- smoking increases risk by 9x
- rupture of an underlying small sub pleural bleb or bulla is thought to be responsible in many cases
See 2019 pneumothorax slide 6
22
Q
What is secondary pneumothorax?
A
- occurs secondary to an underlying lung problem (ex. COPD or asthma)
- secondary to trauma
- iatrogenic: due to diagnostic or therapeutic procedure
See 2019 pneumothorax slide 7
23
Q
What is a tension pneumothorax?
A
- can occur due to any aetiology
- causes a mediastinal shift and CVS collapse
- arises from the development of a one-way valve system at the site of breach in the pleural membrane
- allows air to enter pleural cavity during inspiration but prevents air from leaving during expiration because of a flap that closes on expiration so intrapleural pressure gradually increases
- eventually intrapleural pressure exceed atmospheric pressure
- as a result there is impaired venous return and reduced CO (hypoxaemia and haemodynamic compromise)
See 2019 pneumothorax slide 13-14
24
Q
What are the symptoms and signs of a pneumothorax?
A
History
-sudden onset of pleuritic chest pain and breathlessness
Examination
- occurs on the affected side
- chest movements reduced
- percussion is hyper resonant
- breath sounds are reduced in intensity
See 2019 pneumothorax slide 8
25
What would you see on a CXR on a pt. With pneumothorax?
- right sided pneumothorax
- right side is hyperlucent: darker than normal side
- absent lung markings on right side
- edge of collapsed lung is seen
See 2019 pneumothorax slide 9-10
26
What is the treatment for a pneumothorax?
If pt. Is symptomatic
- small pneumothorax: needle aspiration may be sufficient
- large pneumothorax: insertion of chest drainage
- chest drain placement in the safe triangle
- 5th intercostal space in the mid-axillary line, just above the 6th rib
See 2019 pneumothorax slide 11-12
27
How is tension pneumothorax life threatening?
- mediastinal shift: compresses the normal lung
- increased intrapleural pressure > atmospheric pressure
- venous return is impaired so CO drops
- results in hypoxaemia and haemodynamic compromise
See 2019 pneumothorax slide 15
28
What are the symptoms and signs of a tension pneumothorax?
- severe distress and dyspnoea
- pleuritic chest pain
- fatigue
- tachycardia and hypotension
- raised JVP
- deviated trachea
- displaced apex beat
- hyper-resonant percussion note
- absent breath sounds
- diagnosis is clinical CANNOT wait for cxR confirmation
See 2019 pneumothorax slide 16
29
What would you see in a CXR of a tension pneumothorax?
- trachea: deviated to the left
- heart: displaced to the left
- right lung: hyperlucent with absent lung markings
- edge of collapsed lung visible
See 2019 pneumothorax slide 17
30
How would you treat a tension pneumothorax?
- emergency needle decompression of chest
- insert cannula into 2nd intercostal space in mid-clavicle are line
See 2019 pneumothorax slide 18-20
31
What is a pleural effusion?
- excess fluid in the pleural cavity
- imbalance in the normal rate of pleural fluid production and absorption
See 2019 pneumothorax slide 22-23
32
What is a haemothorax?
-if fluid in pleural space is blood
33
What is a chylothoraX?
-if fluid in pleural space is chyle
34
What is an empyema?
-if fluid in pleural space is pus
35
What are the factors that affect pleural fluid formation?
- depends on “starling forces” in systemic capillaries in PARIETAL pleura
- pulmonary arteries have low pressure so hardly any fluid formation in visceral pleura
- key factors: hydrostatic pressure and colloid osmotic pressure
See 2019 pneumothorax slide 24
36
Explain transudate as a cause of pleural effusion
- has low protein content
- due to increased pleural capillary hydrostatic pressure: congestive cardiac failure
- due to decreased capillary oncotic pressure: low serum albumin levels, cirrhosis; nephrotic syndrome
- commonest cause: congestive heart failure
See 2019 pneumothorax slide 25
37
How is exudate a cause of pleural effusion?
- has high protein content
- due to increased capillary permeability (ex. Inflammation, malignancy)
1. Bronchial carcinoma
2. Pneumonia
3. TB
4. Other
See 2019 pneumothorax slide 26
38
What are the differences between transudate and exudate?
- less protein vs. More protein
- less serum LDH vs. More serum LDH
- main causes
- T: cirrhosis, nephrotic syndrome, PE
- E: malignancy, TB, pancreatitis, pneumonia
See 2019 pneumothorax slide 27
39
What are the symptoms and signs of pneumothorax?
History
- breathlessness of more gradual onset
- pleuritic chest pain
- features of causative disease
Signs/symptoms
- trachea deviates towards unaffected side
- chest movement is reduced on affected side
- percussion is “stony”dull on affected side
- breathing is reduced on affected side
- vocal resonance is reduced
See 2019 pneumothorax slide 28
40
How would the CXR and CT appear for a pt. With pleural effusion?
CXR
- opacity in lower zone
- cant see outline of diaphragm
- upper border curved (meniscus)
CT
- enlarged lymph nodes
- irregular soft tissue thickening of the pleural surface
See 2019 pneumothorax slide 29-31
41
What is the difference between unilateral and bilateral pleural effusion?
- bilateral: blunting of Costco-phrenic angles
- bilateral is more likely due to transudate since it is a more systemic condition
See 2019 pneumothorax slide 32-33
42
How would you treat a pleural effusion?
- treat underling cause
- therapeutic drainage of larger pleural effusions may be required for relief of symptoms (indwelling pleural catheter)
- pleurodesis: obliteration of the pleural space
- usually by introducing talc into pleural space after draining effusion which causes the visceral and parietal pleura to become adherent and obliterate the pleural space
See 2019 pneumothorax slide 34-37
