Pulmonary vascular disease and pleural disease Flashcards
What is the pressure system of pulmonary circuation?
Low pressure
Due to the pulmonary circulation being a low pressure system, with thin walled vessels, what is there low incidence of at normal pressure?
Atherosclerosis
What is pulmonary oedema?
Accumulation of fluid in the lung - interstitium and alveolar spaces
What type of pattern of disease does pulmonary oedema cause?
Restrictive pattern
What are the 2 main pathological causes of pulmonary oedema?
- Haemodynamic (increase in hydrostatic pressure)
2. Due to cellular injury (alveolar lining cells/alveolar endothelium)
What condition causes localised pulmonary oedema?
Pneumonia
What condition causes generalised pulmonary oedema?
Adult respiratory distress syndrome (ARDS)
What is DADS?
Diffuse alveolar damage syndrome
What are 4 causes of shock lung?
- Sepsis
- Diffuse infection (virus, mycoplasma)
- Severe trauma
- Oxygen
What 4 things are involved in the pathogenesis of ARDS after injury (e.g. bacterial endotoxin)
Infliltration of inflamamtory cells
Cytokines
Oxygen free radicals
Injury to cell membranes
Name 3 things involved with the pathology of ARDS
Fibrinous exudate lining alveolar walls (hyaline membranes)
Cellular regeneration
Inflammation
What can be the outcome of ARDS?
Fibrosis (chronic restrictive lung disease)
Who does neonatal RDS occur in?
Premature infants
What causes neonatal RDS?
Deficiency in surfactant (type 2 alveolar lining cells)
How does neonatal RDS cause physical damage to cells?
Increased effort in expanding lungs
What is a detached intravascular mass carried by the blood to a site in the body distant from its point of origin?
Embolus
What is an important cause of sudden death and pulmonary hypertension?
PE
What are 95% of emboli?
Thromboemboli
Where is the source for most pulmonary emboli?
DVT of lower limbs
What are these the effects of - sudden death, severe chest pain/dyspnoea/haemoptysis, pulmonary infarction and pulmonary hypertension?
PE
What do the effects of PE depend on?
Size of embolus
Cardiac function
Respiratory function
What do recurrent small emboli lead to?
Pulmonary hypertension
In a pulmonary infarct (ischaemic necrosis), what artery supply is compromised?
Bronchial artery supply
What are the two classes of pulmonary hypertension?
Primary (rare, young women)
Secondary
What are 4 mechanisms of pulmonary hypertension?
- Hypoxia (vascular constriction)
- Increased flow through pulmonary circulation (congenital heart disease)
- Blockage (PE) or loss (emphysema) of pulmonary vascular bed
- Back pressure from left sided heart failure
Give the steps in the morphology of pulmonary hypertension
- Medial hypertrophy of arteries
- Intimal thickening (fibrosis)
- Atheroma
- Right ventricular hypertrophy
- Extreme cases (congenital heart disease, primary pulmonary hypertension) - plexogenic change/necrosis
What is a pulmonary hypertension complicating lung disease?
Cor Pulmonale
What are three physiological features of Cor Pulmonale?
Right ventricular hypertrophy
Right ventircular dilatation
Right heart failure (swollen legs, congested liver)
What might be seen on a CXR due to right ventricular dilatation?
Cardiomegaly
What is the name for a mesothelial surface lining the lungs and medastinum?
Pleura
What type of cells does the pleura have, that are designed for fluid absorption?
Mesothelial cells
What two types of fluid can you get in a pleural effusion?
Transudate
Exudate
What protein levels are transudate and exudate pleural effusions?
Transudate - low protein
Exudate - High protein
What two conditions can lead to pleural effusion transudate?
Cardiac failure
Hypoproteinaemia
What four conditions can lead to pleural effusion exudate?
Pneumonia
TB
Connective tissue disease
Maliganancy (primary or metastatic)
What two factors can cause pneumothorax?
Trauma
Rupture of bulla
What is a primary pleural neoplasia - malignant - called?
Maligannt mesothelioma
What disease is closely related to mesothelioma?
Asbestosis
What investigation can you do for malignant effusions?
Cytology, biopsy
Where does the dual blood supply for the pulmonary circulation come from?
Pulmonary veins
Bronchial arteries
