Restrictive lung disease Flashcards
Explain a little about the interstitium of the lung (restrictive lung disease)
the connective tissue space around the airways and vessels and space between the basement membranes of the alveolar walls
In the normal alveolar wall, most of the alveolar epithelium (pneumocyte) and interstitial capillary endothelial cell basement membranes are in direct contact.
what sort of process is largely (but not exclusively) involved in restrictive lung diseases?
inflammatory process
Where is the principal location of restrictive lung diseases?
the interstitium of the lung
what does restrictive lung disease mean with compliance?
reduced compliance - stiff lungs
what does restrictive lung disease mean with Fev1/fev
low fev1 and low fvc but the fev1/fev ratio is normal
what does restrictive lung disease mean with ventilation/perfusion
reduces gas transfer (Tco or Kco)- diffusion abnormality
ventilation/perfusion imbalance
when small airways affected by pathology
due to fibrous and inflammation tissue
fev1/fvc figures in spirometry for restrictive lung disease
fev1 = 1.8Litres
fvc = 2.1 Litres
fev1/fvc 0.85
(normal woulf be fev1 = 4L fvc - 4.9L fev1/fvc = 0.91)
Restrictive lung disease presentation
discover on an abnormal chest xray or ct scan
dyspnoea (short of breath on exertion, short of breath at rest as disease progresses)
respiratory failure type 1
heart failure
in restrictive lung disease - explain the inflammatory process
diffuse interstitial lung disease > parenchymal (interstitial lung injury)
causes acute (which can become chronic) or chronic response.
chronic response:
unusual interstitial pneumonitis (ui); granulomatous response; other pattern
all end fibrosis - end-stage honeycomb lung.
an acute inflammatory process for restrictive lung disease
diffuse alveolar damage (DAD)
diagnosis = acute interstitial pneumonia
what is diffuse interstitial damage (dad) or acute interstitial pneumonia associated with
- major trauma - chemical injury (toxic inhalation) - circulatory shock - drugs - infection including viruses (influenza SARScov1 SARScov2) - auto(immune) disease - radiation - can be idiopathic
Histology of diffuse acute damage syndrome DADS
protein-rich oedema fibrin hyalin membranes denuded basement membranes epithelial proliferation fibroblast proliferation scarring - interstitium and airspaces
sarcoidosis
multisystem granulomatous disorder (unknown aetiology)
involving abnormal collections of inflammatory cells that form lumps (granulomata). The disease usually begins in the lungs, skin, or lymph nodes. Less commonly affected are the eyes, liver, heart, and brain. Any organ, however, can be affected.
Histopathology of sarcoidosis
Epitheloid and giant cell granulomas
NOT necrosis/caseation very unusual
little lymphoid infiltrate
variable associated fibrosis
type 4 hypersensitivity reaction
RARELY PROGRESSES TO SIGNIFICANT FIBROSIS AS not type 3 reaction or chronic inflammatory reaction
Sarcoidosis - incidence
multisystem disorder unknown origin
commonly affects young adults (females more than males)
3-4/1000 in Uk
20/100000 in African Americans in USA
low equatorial regions
a disease of temperature climates
Sarcoidosis - what organs does it commonly involve
lymph nodes almost 100% cases lungs >90%
spleen 75% liver 70% skin, eyes, skeletal muscle 50% bone marrow 20%
saliva glands up to 50%
presentation of sarcoidosis
1 yound adults: acute arthralgia (joint pain) erythema nodosum (tender red nodules on the anterior shins) bilateral hilar lymphadenopathy
2 indidental abnormal chest x-ray or ct scan with no symptoms
3 shortness of breath, cough and abnormal chest x-ray
chest x-ray presentation of sarcoidosis
massive enlargement of hilar lymph nodes
presentation ct for sarcoidosis
diffuse interstitial involvement in the lungs with granular lead to fibrosis = respiratory failure
sarcoidosis - will it go away without treatment?
usually is a time-limiting disease
on the rare occasion it may need corticosteroids/
getting a sarcoidosis diagnosis
often can be given a clinical diagnosis - does not need therapeutic intervention or pathological sample.
- imaging
- serum, calcium +++ and ACE
- biopsy
hypersensitivity pneumonitis
thermophilic actinomycetes (farmers lung)(high-temperature aerobic bacteria which belong to the group actinomycetes) mycropolyspora faeni, thermoactinomycytes vulgaris
bird/animal proteins - faeces, bloom
fungi aspergillus spp
chemicals
others.
A 48-year-old woman of African ethnicity presents to her family doctor complaining of a lump in her neck. She reports that the lump has been there for the past week and has not increased in size significantly. She denies any pain or swallowing difficulty. Her previous medical history is unremarkable, and she has never been admitted to the hospital before, except for a visit to the ophthalmologist last year for red-eye, which necessitated treatment with topical steroid drops. Upon examination, the doctor notices some red tender nodules on the patient’s shin but the patient says that these come and go and do not bother her much. A chest x-ray reveals bilateral hilar lymphadenopathy with no other significant findings. Which one of the following is usually associated with this patient’s condition?
Elevated angiotensin-converting enzyme levels
Hypocalcemia
Poor sleep
Exposure to silica
Pain in the small joints of the hand
This patient presented with the signs and symptoms suggestive of sarcoidosis. The diagnosis is supported by the symptoms of a neck lump, which is most likely to be an enlarged lymph node, as well as examination findings of tender nodules on the shin, which are called erythema nodosum. In addition, there is a history of red-eye necessitating treatment with steroids and sarcoidosis patients often have eye involvement in the form of uveitis. The chest X-ray findings confirm the presence of bilateral lymphadenopathy which is one of the findings in sarcoidosis. Angiotensin-converting enzyme levels are usually elevated in sarcoidosis and would further support a diagnosis of sarcoidosis.
hypersensitivity pneumonitis presentation
acute
Acute presentation - fever; dry cough; myalgia; chills (4-9 hours after allergen exposure) crackles, tachypnoea, wheeze, precipitating antibody
hypersensitivity pneumonitis presentation
Chronic
insidious, malaise, shortness of breath, cough, low-grade illness, crackles and some wheeze.
*Can lead to respiratory failure gas transfer low = history is important*
histology of hypersensitivity pneumonitis
immune complex-mediated combines type 3 and 4 hypersensitivity
soft centriacinar epitheloid grnulomata
interstitial pneumonitis
foamy histiocytes
bronchiolitis oblitirans
upper zone disease.
Respiratory alkalosis
Common causes
anxiety leading to hyperventilation
pulmonary embolism
salicylate poisoning*
CNS disorders: stroke, subarachnoid haemorrhage, encephalitis
altitude
pregnancy
*salicylate overdose leads to a mixed respiratory alkalosis and metabolic acidosis. Early stimulation of the respiratory centre leads to a respiratory alkalosis whilst later the direct acid effects of salicylates (combined with acute renal failure) may lead to an acidosis
A 60-year-old man presents to his GP with a 10-day history of a productive cough and shortness of breath. His GP prescribes antibiotics. 1 week later his symptoms are not improving and he now has a persistent fever and pain on inspiration. The GP sends him for a chest x-ray which is suggestive of an empyema. What is the most likely causative organism?
Mycobacterium tuberculosis Pneumocystis jirovecii Streptococcus pneumoniae Haemophilus influenzae Listeria monocytogenes
An empyema is a collection of pus in the pleural space. It is a potential complication of pneumonia and, in this case, is the cause of the gentleman’s pleurisy.
The commonest cause of empyema is Streptococcus pneumoniae, which is also the commonest cause of pneumonia.
where does hypersensitivity pneumonitis usually begin?
centriacinar region
this condition is associated with inhaled antigens - precipitated centriacinar region - laminar airflows converts to gas diffusion tiny particulate or macromolecular particles
biopsy here.
histology difference sarcoidoma and hyprsensitivity pneumonitis
granulomar in hypersensitivity pneumonitis tend to be softer and more diffuse in character
granulomas - a chronic inflammatory process not seen in sarcoidosis
alveolar walls around respiratory bronchioles subject to chronic inflammatory process
which zone of the lung does hyperinflammatory pneumonitis tend to affect
upper zone due to inhaled antigens - clearance mechanisms in the upper parts of the lung. not as efficient in lower parts.
idiopathic pulmonary fibrosis
connective tissue, drugs, asbestos, viruses
pathological process present in lungs has PIF
what is the fibrosis or end-stage of honeycomb lung circumstance
increased mortality or DADS can die within disease when acute
what are conditions of usual interstitial pneumonitis (UIP)
idiopathic pulmonary fibrosis
it is almost routine patients end up with end-stage honeycomb lung and die of that disease.
pathology process of usual interstitial pneumonitis
maybe seen in connective tissue diseases - esp scleroderma and rheumatoid disease
drug reaction
post-infection
industrial exposureasbestos
others
most are idiopathic - hence idiopathic pulmonary fibrosis (IPF)
cryptogenic fibrosis alveolitis (CFA)
Histopathology of usual interstitial pneumonitis
Patchy interstitial chronic inflammation
- type 2 pneumocyte hyperplasia
- smooth muscle and vascular proliferation
- evidence of old and recent injury; temporal heterogeneity; spatial heterogeneity
- proliferating fibroblastic foci
pneumonia: why hypoxaemia?
vq mismatch bronchitis/bronchopneumonia (some ventilation of abnormal alveoli) - not enough)
overall measurement of o2 in blood falls
shunt - severe bronchopneumonia - lobar pattern with large areas of consolidation
where is the interstitium?
the space between the epithelium side of the alveolus and the endothelium of the capilarry
in picture you see normal alveolus and thin membrane - the right is very thickened breathless patient
how to investigate for dsarcoidosis
take history
chest x-ray (chest x-ray swelling of glands hilum)
do chest extrays affect prognosis for those with sarcoidosis?
can stage 1 to 4
xray presentation in idiopathic pulmonary fibrosis
non-specific shadowing at the base.
a hint of sternotomy wired could indicate cardiac surgery so past of? LVF indicator for IPF developing
