1
Pulmonary Pathology and Pathogenesis:
RESTRICTIVE DISEASE
,2
Sources
● Kumar, et al.- Kumar and Clark’s Clinical Medicine (8thed., 2012): Chapter 15
● Jameson, et al.- Harrison's Principles of Internal Medicine (20th ed., 2018): Chapters
2, 9 & 13
Introduction
● What are restrictive diseases?
➔ They are diseases characterised by impaired airway filling due to
fibrosis of alveolar septae
● General Characteristics
➔ Restrictive = ↓Compliance, ↑Elastance→ Problem getting air in.
➔ ↓DLCO in ILD. Normal DLCO in neuromuscular disorders.
➔ ↑DLCO in obesity, ↓TLC, ↓RV.
➔ Increase in radial traction, so tethered more strongly and airways
remain open
➔ FEV1↓, FVC↓↓ → FEV1/FVC ratio normal or increased
● Restrictive vs Obstructive
➔ FEV1 and FVC ratio are decreased in obstructive whereas normal in
restrictive
Figure 1: Etiology and types of obstructive diseases vs restrictive diseases
, 3
Figure 2: Pathophysiological differences between obstructive diseases and restrictive
diseases.
● Types
➔ Extra pulmonary (Characteristics and causes)
➢ Characterised by external impairment of lung filling
➢ Can be caused by:
1. Conditions affecting the chest wall such as
kyphoscoliosis, obesity hypoventilation syndrome
(AKA Pickwickian syndrome in people with BMI >50,
hypoventilation is as a result of decreased central drive
to breathe)
2. Diaphragmatic disease
3. Neuromuscular diseases: e.g. Guillain-Barré,
poliomyelitis and past polio.
➔ Intrapulmonary (Definition, characteristics and types)
Intrapulmonary restrictive diseases
● Introduction
➔ They account for 15% of respiratory failure
➔ It involves diffuse lung injury and inflammatory responses that can
lead to lung fibrosis
● General Characteristics
➔ Thickened alveolar interstitium as a result of accumulation of
inflammatory cells, mesenchymal cells and collagen-rich extracellular
matrix
➔ Fibrosis of lung parenchyma and capillary remodelling
Pulmonary Pathology and Pathogenesis:
RESTRICTIVE DISEASE
,2
Sources
● Kumar, et al.- Kumar and Clark’s Clinical Medicine (8thed., 2012): Chapter 15
● Jameson, et al.- Harrison's Principles of Internal Medicine (20th ed., 2018): Chapters
2, 9 & 13
Introduction
● What are restrictive diseases?
➔ They are diseases characterised by impaired airway filling due to
fibrosis of alveolar septae
● General Characteristics
➔ Restrictive = ↓Compliance, ↑Elastance→ Problem getting air in.
➔ ↓DLCO in ILD. Normal DLCO in neuromuscular disorders.
➔ ↑DLCO in obesity, ↓TLC, ↓RV.
➔ Increase in radial traction, so tethered more strongly and airways
remain open
➔ FEV1↓, FVC↓↓ → FEV1/FVC ratio normal or increased
● Restrictive vs Obstructive
➔ FEV1 and FVC ratio are decreased in obstructive whereas normal in
restrictive
Figure 1: Etiology and types of obstructive diseases vs restrictive diseases
, 3
Figure 2: Pathophysiological differences between obstructive diseases and restrictive
diseases.
● Types
➔ Extra pulmonary (Characteristics and causes)
➢ Characterised by external impairment of lung filling
➢ Can be caused by:
1. Conditions affecting the chest wall such as
kyphoscoliosis, obesity hypoventilation syndrome
(AKA Pickwickian syndrome in people with BMI >50,
hypoventilation is as a result of decreased central drive
to breathe)
2. Diaphragmatic disease
3. Neuromuscular diseases: e.g. Guillain-Barré,
poliomyelitis and past polio.
➔ Intrapulmonary (Definition, characteristics and types)
Intrapulmonary restrictive diseases
● Introduction
➔ They account for 15% of respiratory failure
➔ It involves diffuse lung injury and inflammatory responses that can
lead to lung fibrosis
● General Characteristics
➔ Thickened alveolar interstitium as a result of accumulation of
inflammatory cells, mesenchymal cells and collagen-rich extracellular
matrix
➔ Fibrosis of lung parenchyma and capillary remodelling
