M103 T4 L13 Flashcards
1
Q
What are the two types of xray shadowing?
A
alveolar
interstitial
2
Q
What four structures are included under the interstitium?
A
alveolar endothelium
capillary endothelium
basement membrane
connective tissue
3
Q
Which three things can thicken the interstitium in disease?
A
Fluid
Cells
Fibrosis
4
Q
What is lung fibrosis thought to be caused by?
A
aberrant wound healing
the lung could be exposed to an injury
the wound healing mechanism goes into overdrive
causes increased deposition of extracellular matrix in the interstitium
5
Q
What does the extracellular matrix consist of?
A
3D fibre mesh filled with macromolecules of collagen and elastin
6
Q
What features does the extracellular matrix provide the lung with?
A
elasticity
low resistance for gas exchange
7
Q
What are the three classifications of interstitial lung diseases?
A
environmental exposure
systemic inflammatory diseases
idiopathic
8
Q
What are two examples of intersitial lung diseases caused by environmental exposure?
A
occupational lung disease
hypersensitivity pneumonitis
9
Q
What are the two common causes of hypersensitivity pneumonitis?
A
mold
bird proteins
10
Q
What are the three common causes of occupational lung disease?
A
silicosis
coal miners lung
asbestosis
11
Q
What is silicosis caused by?
A
exposure to silica
12
Q
What is coal miners lung caused by?
A
coal dust exposure
13
Q
What is an example of an idiopathic intersitial lung disease?
A
Idiopathic pulmonary fibrosis
14
Q
What are two examples systemic inflammatory ILDs?
A
connective tissue disease
sarcoidosis
15
Q
What are the six main causes of intersitial lung disease?
A
drugs idiopathic sarcoidosis connective tissue disease hypersensitivity pneumonitis occupational lung diseases
16
Q
What are the symptoms of intersitial lung disease?
A
slowly progressive exertional dyspnoea
non-productive cough
dry, inspiratory bibasal “Velcro” crackles
sometimes have clubbing of fingers
abnormal pulmonary function test results with restriction and impaired gas exchange
17
Q
What are the four different types of patterns that can be seen on a lung HRCT?
A
basal distribution
subpleural
traction bronchiectasis
honeycombing
18
Q
How can IPF be managed?
A
anti-fibrotic drugs
lung transplant
supportive care
19
Q
How much do anti-fibrotic drugs cost?
A
£24,000 per person/yr
20
Q
What are two examples of anti-fibrotic drugs?
A
pirfenidone
nintedanib
21
Q
Why can anti-fibrotic drugs only be prescribed by specialist centres?
A
because they are very expensive
22
Q
What is the function of anti-fibrotic drugs?
A
to slow rate of disease progression of the interstitial lung disease
23
Q
What is the only criteria for being prescribed anti-fibrotic drugs?
A
that the patient has a diagnosis of idiopathic disease
that the patient has an FVC of between 50 - 80 % of their normal predicted FVC
24
Q
Why are anti-fibrotic drugs often poorly tolerated?
A
significant weight loss
significant GI upset (with nausea and diarrhoea)
photosensitivity (have to wear sunblock at all times)
25
How is suitability assessed for a lung transplant?
usually under the age of 65
with no significant comorbidities
RARE to be suitable - ILB is a disease of the elderly
26
What are the common causes for deterioration in IPF patients?
infection
pulmonary embolism
pneumothorax
acute exacerbation
27
What is the only deterioration when IV steriods can be used for treatment in IPF patients?
when the patient develops acute exacerbation
28
What are some co-morbidities of IPF patients?
gastroesophageal reflux disease
COPD (from history of smoking)
lung cancer
29
How are IPF patient's symptoms palliated?
assessed for ambulatory oxygen or for long term oxygen
| pulmonary rehab
30
What happens during long term oxygen delivery?
oxygen is provided for 15 to 16 hours per day
31
What si the effect of long term oxygen delivery for an IPF patient?
reduces chronic hypoxia
| reduces their risk of cor pumonale
32
Which two things are improved through pulmonary rehab?
lung capacity
| quality of life
33
Why are benzodiazepines and opiates prescribed for IPF patients?
to help manage anxiety and the sensation of breathlessness
34
What is the effect of hypersensitivity pneumonitis?
diffuse inflammation of the lung parenchyma
| especially in the upper lobes
35
What is the cause of hypersensitivity pneumonitis triggered by?
an inhaled antigen
36
What could hypersensitivity pneumonitis be triggered by?
bird fancier's lung
farmers lung
aspergillus
could be anything (e.g. playing bagpipes not cleaning them) - 50% of cases where the causing antigen is unknown
37
What causes bird fancier's lung?
avian proteins present in the dry dust of the droppings and sometimes in the feathers of a variety of birds
38
What are the three classes of hypersensitivity pneumonitis symptoms?
acute
subacute
chronic
39
What are the acute symptoms of hypersensitivity pneumonitis?
```
shortness of breath
cough
fever
malaise
crackles within 4-6 hours of heavy exposure
often misdiagnosed as infection
```
40
What are the sub-acute symptoms of hypersensitivity pneumonitis?
gradual onset of symptoms
| weight loss - common
41
What are the chronic symptoms of hypersensitivity pneumonitis?
insidious onset
history of acute episodes may be absent
even after antigen removal, symptoms may continue
may lead to irreversible fibrosis
42
What condition is likely to be responsible for most cases of hypersensitivity pneumonitis?
many years of continuous or intermittent inhalation of the inciting agent
43
What type of complex is produced during the precipitin test?
IgG antibody-antigen complexes
44
How is hypersensitivity pneumonitis diagnosed?
using the precipitin test
45
How is hypersensitivity pneumonitis diagnosed?
using the precipitin test
46
What are the three disadvs of the precipitin test when diagnosing HP?
there are an infinite number of possible antigens so it might be imposssible to find an antigen to use in the precipitin test / might all produce negative results
the precipitin test may be positive in asymptomatic individuals
negative results does not exclude hypersensitivity pneumonitis
47
How is HP managed?
once identified, the patient needs to avoid the inciting antigen
in early disease, is usually steroid-responsive (IV)
48
What are three common drugs that could trigger ILD?
Nitrofurantoin
Amiodarone
Methotrexate
49
What are four connective tissue diseases that are related to ILD?
Rheumatoid Arthritis
Scleroderma
Sjogrens
Polymyositis
50
What group of people are connective tissue disease-related ILD common in?
Younger patients
| Female preponderance
51
What condition histories need to be taken from patients who might have connective tissue disease-related ILD?
dryness of the eyes or mouth (sicca)
Raynaud’s
joint pain/swelling
rashes
52
How is connective tissue disease-related ILD managed?
managed in liasion with staff in rheumatology
| the underlying disease needs to be treated
53
Why are bloods done in new IDL patients?
to look for indications that it might be connective tissue disease-related ILD
54
What two substances are found in the blood tests that suggest that the patient has connective tissue disease-related ILD?
antinuclear antibodies
rheumatoid factor
angiotensin-converting enzyme (sometimes)
55
How is the underlying disease treated in connective tissue disease-related ILD? (bis)
biologics
immunosuppression
steroids
56
What is the FEV1/FVC ratio expected to be in patients with ILD?
normal to high
57
Which condition might confuse the lung function test results of ILD patients?
coexistent COPD
58
What will be seen on the chest xray of an ILD patient?
reticular shadowing
59
Why are HRCTs the cornerstone of diagnosing ILD patients?
bc the pattern of disease abnormality seen on the scan can inform on the likely aetiology
60
What percentage of HRCTs are fully diagnostic?
60%
61
What is the use of lung biopsies in ILD patients?
to try and differentiate from idiopathic pulmonary fibrosis which is irreversible
usually not done - elderly
62
How is ILD treated pharmacologicaly?
immunosupression drugs
| anti-fibrotics
63
What immunosupression drugs can be used to treat ILD?
prednisolone
hydoxychloroquine
mycophenolate mofetil
methotrexate
64
What type of disorder is sarcoidosis?
a multisystem granulomatous disorder
65
How is sarcoidosis recognised?
the presence of non-necrotising granulomas found when a biopsy is performed on the affected tissues
66
What is sarcoidosis caused by?
cause unknown
67
What groups is sarcoidosis common in?
more common and severe in Afro-caribbeans
some familial clusters (a suggested genetic link)
middle aged people
68
How does sarcoidosis differ for Afro-Carribeans?
three times more common
have more severe extra-thoracic symptoms
typically have more severe disease
69
What age group is affected most by sarcoidosis? What percentage of total cases occurs in this age group?
30 - 60 year olds
| 75%
70
What is the histological cause behind sarcoidosis?
an unknown antigen stimulates an immune response by CD4+ T cells and alveolar macrophages
71
What is the result of the immune response triggered in sarcoidosis?
the CD4+ T cells and alveolar macrophages aggregate to form epithelioid cells and further antigens
stimulation then leads to further aggregation into multinucleate giant cells
72
What happens to the multinucleate giant cells in sarcoidosis?
they organise into granulomas
73
What is the difference between the granulomas present in sarcoidosis and those in TB or fungal infections?
in sarcoidosis, they are non necrotising / non caseating granulomas
74
What is required to confidently diagnose sarcoidosis?
a biopsy demonstrating granulomas along with clinical picture
75
How does sarcoidosis affect the skin?
erythema nodosum
lupus pernio
plaques
nodules
76
What other systems of the body does sarcoidosis affect other than the lungs?
the skin
the eyes
the peripheral nerves
77
How does sarcoidosis affect the eyes?
anterior uveitis
78
Why might a sarcoidosis patient have had a lymph node biopsy?
patients with sarcoidosis may have significant systemic upset and can easily be confused with cancer or typically lymphoma
it would have been performed for a suspected malignancy
it's not until the lymph node is removed and examined that they find these non necrotising granulomas
79
How can sarcoidosis be recognised from a blood test?
a positive result for hypoglycaemia
80
Why might a sarcoidosis patient have hypoglycaemia?
activated cells within sarcoid granulomas secrete the
enzyme which converts inactive vitamin D to its activated form
activated vitamin D is important for the absorption of calcium within the body
AAR patients with sore quote have increased activated vitamin D levels and hence hypoglycaemia
81
How does sarcoidosis affect the peripheral nerves?
Bell’s Palsy
| mononeuropathies
82
What three conditions are included in the triad of lofgren syndrome?
Erythema Nodosum
Bilateral Hilar Lymphadenopathy
Arthralgia
83
What are symptoms of lofgren syndrome beyond the triad?
systemic upset
| fever
84
Why is a diagnosis of Lofgren Syndrome not bad news?
it has an excellent prognosis
it's usually self limiting
usualy has no need for any treatment
85
When might pulmonary sarcoidosis be entirely asymptomatic?
if the sarcoidosis is isolated to the lymph nodes in the chest
86
What are the lung-specific symptoms of pulmonary sarcoidosis?
cough
breathlessness with exertion
chest tightness
87
What are the systemic symptoms of pulmonary sarcoidosis?
```
fatigue (can be extremely difficult to treat)
sweats
weight loss
fevers
can lead to lymphoma
```
88
What happens to patients with pulmonary sarcoidosis?
majority - remission (with or without treatment)
| minority - chronic inflammation continues and may eventually lead to fibrosis
89
What combination is used to diagnose sarcoidosis?
clinical picture
exclusion of alternative diagnoses ( esp. lymphoma and TB)
ideally biopsy of affected tissue
90
What do the baseline tests look at when diagnosing sarcoidosis?
```
renal function
liver function
calcium
serum ACE
CXR
ECG
```
91
What is serum ACE secreted by in sarcoidosis patients?
activated alveolar macrophages in granulomas
92
Why is serum ACE not a reliable diagnostic identifier for sarcoidosis?
low sensitivity - only about 60% of patients will have serum ACE
poor specificity - serum ACE may be raised in patients who do not have sarcoidosis
peripheral blood ACE levels vary
there is no correlation with the chest xray stage of disease
93
Why are there variations in peripheral blood ACE levels?
bc there are polymorphisms in the ACE gene
94
When can it be beneficial to use serum ACE?
in some patients, monitoring the SACE can be a useful way of assessing disease activity
95
How can it be beneficial to use serum ACE?
in some patients, there can be clear elevations of the serum ACE when their disease is active
then the levels normalise when in remission
96
In what situations might systemic treatment be administered for sarcoidosis?
if the patient has cardiac sarcoidosis
if the patient has neurological sarcoidosis
if the patient has an ocular disease that is not responding to topical treatment
97
What does "ocular disease not responding to topical treatment" mean?
if the patient has eye disease that is not responding to eyedrops
98
What is the treatment plan for pulmonary sarcoidosis?
steroids improves the symptoms in the short-term
often less severe than extra-thoracic disease with spontaneous remission common so a lot of the time, no treatment needed
the long-term effect on natural history of disease not known
99
How long are corticosteroids used to treat sarcoidosis patients?
6 months - 2 years
100
Why are corticosteroids used to treat sarcoidosis patients?
inhaled corticosteroids may provide symptomatic benefit
| AAR they might not need systemic treatment
101
When might additional immunosuppressants be used to treat sarcoidosis patients?
when we're unable to reduce the steroid dose bc the patient keeps getting flares of disease
very severe progressive disease from the outset
102
What does a restrictive pattern from a spirometry indicate compared to that of an obstructive pattern?
restrictive - indicates that there is a problem
| obstructive - indicates that there is a problem, specifically in the airways
103
How is obstructive spirometry useful diagnostically?
for reversible airflow obstruction (asthma)
| to indicate that there is fixed airflow obstruction in a smoker (COPD)
104
How is restricted spirometry useful for?
monitoring the FEC
| acts as a part of the treatment criteria for its empathic pulmonary fibrosis
105
Which two conditions can obstructive spirometry be useful for monitoring change in?
acutely - Guillain-Barre
| chronically - COPD?
106
How is restricted spirometry useful for monitoring the FEC?
indicates the risk of impending ventilatory failure
| indicates the severity of the ILD
107
Why do patients get restrictive spirometry?
when lung expansion is restricted
| when there is loss of lung volume
108
What represents the total lung capacity?
FVC
109
Why is getting the FVC value easy?
can be done in clinic
| is useful for disease monitoring
110
What can cause restrictive pattern spirometry?
Extensive burns, scleroderma (skin layer)
Raised BMI (subcutaneous tissue layer)
Kyphoscolios (thoracic cage layer)
e.g. MND, Guillain-Barre (neuromuscular system layer)
Pleural thickening (pleural layer)
Pneumonectomy, pleural effusion (caused by the loss of lung volume)
ILD (caused by lung parenchyma)
