Respiratory Disorders 3

Question 1

What are the 3 lung diseases of vascular origin?

Answer 1

1. Pulmonary congestion + pulmonary oedema
2. Pulmonary embolism
3. Pulmonary hypertension

Question 2

Pulmonary congestion + oedema has 2 main causes. What are they?

Answer 2

1. Haemodynamic

2. Microvascular injury

Question 3

What are the 2 haemodynamic causes outside the lung and 1 haemodynamic cause inside the lung that causes pulmonary congestion + oedema?

Answer 3

Outside:

1. Increased hydrostatic pressure e.g. from mitral stenosis, left sided cardiac failure
2. Decreased oncotic pressure e.g. from hypoalbuminaemia

Inside

1. Increased hydrostatic pressure, from:
   - Decreased cross-sectional vascular area: loss of BVs (emphysema), blockage of BVs (emboli)
   - Fibrous scar tissue in lung: constriction of BVs
   - Chronic inflammation: and resultant leakage of BVs

Question 4

What 4 things does increased hydrostatic pressure result in in the lungs?

Answer 4

1. More fluid in basal regions of the lungs (gravity)
2. Engorgement of vessels
3. Microhaeorrhages
4. Macrophages with haemosiderin

*** all of thee result in a person coughing up pink, frothy sputum

Question 5

Microvascular disease most commonly in the form of DIFFUSE ALVEOLAR CAPILLARY DAMAGE is the second cause of pulmonary congestion + oedema. What are 5 characteristics of DACD?

Answer 5

1. Normal hydrostatic pressure
2. Inflammatory loss of endothelial ‘seal’
3. Formation of a hyaline membrane - fibrin +++ as well as dead cells
4. Alveolar response - type II pneumocyte proliferation
5. Potential to cause ARDS

Question 6

ARDS can cause damage to endothelium (3 ways) and damage to epithelium (4 ways)

Answer 6

Endothelium: septicaemia (systemic infection), virus infection (systemic), radiation
Epithelium: virus infection, inhaled toxins/irritants, oxygen toxicity, near drowning

Question 7

Is resolution common with ARDS? What are 5 physical characteristics that result from it?

Answer 7

1. Intra-alveolar fibrosis
2. Interstitial thickening and fibrosis (due to accumulation of inflammatory cells)

*** getting air out of this stiff lung is v hard

3. Infiltrated/consolidated/collapsed areas
4. Poor local compliance - poor aeration
5. Ventilation-perfusion mismatch

Question 8

Are you completely stuffed if an emboli clogs the pulmonary artery causing pulmonary embolism?

Answer 8

No because lungs are double supplied with arterial blood from both the pulmonary and bronchial arteries

Question 9

The outcome of pulmonary embolism is dependent on 2 things. What are they?

Answer 9

1. Extent of blockage: small = infarction, large = sudden death
2. Existent pulmonary disease: previous pulmonary emboli or pulmonary hypertension etc. A new PE will be haemorrhagic, an old one will be fibrotic

Question 10

What is the BP required to diagnose PULMONARY HYPERTENSION?

What are 3 causes of PH?

Answer 10

PH = >25% aortic pressure

1. Increased flow and/or pressure
2. Increased vascular resistance
3. Increased left heart resistance

Question 11

Pulmonary Hypertension can be catagorised as PRIMARY or SECONDARY. What is a reason for each?

Answer 11

Primary: v rare to have this - caused by autoimmune smooth muscle or endothelium dysfunction
Secondary: caused by something else
- COAD or Restrictive Airways Disease: destruction (fewer vessels) and fibrosis (loss of compliance)
- Heart disease (mitral stenosis)
- Recurrent thromboemboli
*** depending on which disease is causing the hypertension will determine the rate/extent of the progression of the hypertension

Question 12

What is ultimately the outcome of pulmonary hypertension?

Answer 12

Right ventricle hypertrophy also occurs and ultimately right-sided heart failure