Lower RTI2 Flashcards
What pattern do chronic interstitial lung diseases show on flow-volume loop?
Restrictive lung pattern on flow volume loop.
What are chronic interstitial lung diseases?
Heterogeneous group of disorders characterized predominantly by inflammation and fibrosis of the pulmonary connective tissue.
What are the types of chronic interstitial lung diseases?
Fibrosing diseases (usual interstitial pneumonia, non-specific interstitial pneumonia, cryptogenic organising pneumonia, autoimmune related pneumonia)
Granulomatous (Sarcoid, hypersensitivity pneumonitis)
Eosinophilic
Smoking related (Desquamative interstitial pneumonia, respiratory bronchitis)
Other
[important to know the categories not individual conditions]
What is honeycomb lung?
Thickening of septa between alveoli resulting in rigid lung with larger airspaces.
What is sarcoidosis?
Systemic granulomatous disease with unknown aetiology affecting liver, lung, and brain.
What lung condition is lung sarcoidosis very similar to?
TB, in its granulomatous nature.
How common is hilar lymphadenopathy in sarcoidosis?
90% of cases
What kind of granulomas are found in sarcoidosis?
Collection of big histiocytes with no necrosis in the middle.
What happens to the lungs in sarcoidosis?
Granuloma (non-necrotising) formation
Hilar lymphadenopathy
Pulmonary fibrosis
Lymph node enlargement
How is sarcoidosis diagnosed?
Other causes of symptoms must first be excluded.
What is pneumoconiosis?
Pulmonary fibrosis caused by inhaled dust.
Who is pneumoconiosis commonly seen in?
People who work in coal mines
What 2 blood supplies does the lung receive?
Pulmonary circulation (alveoli supply)
Systemic (Bronchial) circulation (Supply lungs until bronchioles prior to alveoli)
How many bronchial arteries does the lung receive?
2 on the left coming off descending aorta and 1 on the right
Can adults deal with losing bronchial arterial circulation?
Blood flow to bronchioles isn’t compromised too much due to nature of the anastomoses.
What happens if pulmonary circulation is broken?
Infarction of terminal airways.
What is an infarct?
An area of ischaemic necrosis caused by occlusion of vascular supply to affected tissue
What is the most common cause of pulmonary infarct?
Small/ medium sized Embolus (other causes include trauma and vasculitis) [big emboli kill before infarct even happens]
Where do lung infarcts tend to be?
Peripheral due to bronchial tree receiving anastomoses from pulmonary circulation and bronchial circulation.
What shape and colour do pulmonary infarcts tend to have?
Wedge-shape and haemorrhagic (red)
What are the types of emboli?
Thromboemboli
Air/gas emboli
Fat emboli
Amniotic fluid emboli
Septic emboli
Foreign body emboli
What provoking factors result in acute thromboemboli formation?
Surgery, burns, trauma, period of immobilisation, commencement of estrogen therapy, and pregnancy/post partum
What chronic factors cause thromboemboli to form?
Primary:
Clotting abnormalities (eg factor V leiden)
Secondary:
Obesity
Cigarette smoking
Hypertension
Age >60
Malignancy
What are the 3 components that predispose to thrombis in virchows triad?
Endothelial injury
Abnormal blood flow
Hypercoagulability
What are the 2 main effects of a pumlonary embolism?
Mechanical (stops blood flow and leads to mismatch between ventilation and perfusion, and increases right ventricular pressure)
Inflammatory cascade and thrombogenic effects (cytokines and other inflammatory mediators, damage to and activation of endothelium)
What are the mechanical effects of a PE?
Blockage of blood from reaching the lungs
Ventilation Perfusion mismatch
Increased right ventricular pressure
What are the inflammatory effects of a PE?
Cytokine production
Damage to and activation of endothelium promoting indiscriminate clotting
Consumption of platelets and clotting factors with paradoxical bleeding in DIC
What is the effect of large emboli in the lungs?
Acute right heart failure and sudden death
“saddle embolus at bifurcation of pulmonary arteries.
Sudden onset shortness of breath, chest pain, collapse, unconsciousness
What is the effect of smaller emboli?
Pulmonary haemorrhage with or without infarct, ventilation perfusion mismatch, and hypoxia.
Sudden onset shortness of breath and chest pain.
Can be single or multiple and can be symptomatic or asymptomatic.
Can lead to pulmonary hypertension and chronic RHF
What are possible sequelae of a PE?
Based on degree and size of embolus:
Lysis can occur
Superimposed thrombus/inflammation/extension of infarct
Organisation and recanalisation
How does air/gas embolism occur?
Surgery or trauma causes normal air emboli
Nitrogen can cause embolism (nitrogen decompression sickness)
What causes fat emboli to form?
Fracture of long bones
Severe soft tissue injury
Burns
What kind of cells are seen in fat emboli?
Adipocytes with or without associated haemopoietic marrow elements.
What are the symptoms fat embolism syndrome?
Pulmonary insufficiency
Neurological symptoms (irritability, retlessness, delirium)
Intravascular coagulation with anaemia
Fatal in 5 - 15% of cases
What causes amniotic fluid emboli?
In rare cases, a tear in placental membrane or rupture of uterine veins allow amniotic fluid into maternal circulation.
What complications arise from amniotic fluid emboli?
Permanent neurological damage in 85% of survivors
Pulmonary oedema
DIC
Acute lung injury
What is pulmonary hypertension?
Mean pulmonary artery pressure >=25mmHg or >30mmHg during exercise
How can pulmonary hypertension arise?
Increase in pulmonary blood flow
Increase in pulmonary vascular resistance
Increase in left heart resistance to blood flow (mitral stenosis)
Idiopathic
What are the groups of pulmonary hypertension by WHO classification?
Group 1: Pulmonary arterial hypertension
Group 2: Pulmonary hypertension owing to Left Heart Disease
Group 3: Pulmonary hypertension caused by lung disease
Group 4: Chronic thromboembolic pulmonary hypertension
Group 5: Pulmonary hypertension with unclear multifactorial mechanisms (idiopathic)
WHO groups good way to remember it.
Pulmonary hypertension can be caused by:
Inflow: Left to right shunt
Pulmonary bed: Group 1/3/4/5
Outflow: Group 2. Pulmonary hypertension owing to left heart disease
How is pulmonary circulation remodeled in people with pulmonary hypertension?
Genetic changes (Bone morphogenetic protein receptor 2)
Serotonin/other mediators
Inflammation
Endothelial damage and thrombosis
Hypoxia - oxidative damage
What does bone morphogenetic protein receptor 2 do?
Member of transforming growth factor beta superfamily and is widely expressed in pulmonary artery endothelium.
End effect of mutations in this gene is dysfunction and proliferation of endothelial cells and vascular smooth muscle.
How do people present in the clinic with pulmonary hypertension?
Right heart failure
Failure to oxygenate
Arrhythmias
In idiopathic group death from right heart failure occurs within 2 to 5 years in 80% of patients
Patients usually come in late into the course of the disease due to its lack of symptoms in the early stage.
What symptoms are seen in right heart failure?
Chest pain
Abdominal discomfort
Peripheral oedema
SOB
What are pathological findings of pulmonary hypertension?
Medial hypertrophy of pulmonary muscular and elastic arteries with intimal fibrosis
Pulmonary artery atherosclerosis
Right ventricular hypertrophy
End stage can form plexiform arteriopathy
Changes can involve entire pulmonary arterial system
Narrowing of vessel lumina
Increase vascular resistance
How is pulmonary hypertension treated?
Depends on underlying cause, the cause is treated.
Group 1 have been treated with vasodilators with some success
Lung transplant provides definitive treatment for some patients
Where do most pulmonary haemorrhages occur?
They occur focally due to what caused them (Tumour, abscess, infection, etc)
How does diffuse pulmonary haemorrhage occur?
Range of settings and is usually associated with immunologically mediated or inflammatory diseases.
Can occur in DAD/ALI/ARDS patterns of interstitial lung disease
Some cases are idiopathic
How do people with pulmonary haemorrhage present?
Haemoptysis
How can localised pulmonary haemorrhage be diagnosed?
Haemoptysis and a thromboembolism/tumour/abscess/etc on chest scans
What are the types of diffuse pulmonary haemorrhage?
Vasculitis associated
Without vasculitis
What is goodpasture syndrome?
Uncommon autoimmune disease in which kidneys and lungs are damaged by autoantibodies against the non-collagenous domain of the alpha3 chain of collagen IV.
What is Granulomatosis with pulmonary angiitis (Wegner’s granulomatosis)?
A systemic inflammatory disorder affecting blood vessels.
What are the characteristic lung symptoms of granulomatosis with pulmonary angiitis (Wegner’s granulomatosis)?
Nodular lung lesions
Necrosis, vasculitis and granulomatous inflammation
Diffuse pulmonary haemorrhage.
What results would serological tests show in granulomatosis with polyangiitis?
c-ANCA > p-ANCA
