32. Restrictive disorders. Etiology and pathogenesis of pulmonary edema, pneumothorax, pneumonia and interstitial lung disease.

Restrictive disorders. Etiology and pathogenesis of pulmonary edema and pneumothorax

• Can be restrictive diseases of the lung or chest wall

1. Lung (pulmonary fibrosis or pulmonary edema)

• ↑ stiffness and thickness of lungs
• ↓ lung compliance
• ↑ work of breathing
• ↓ standard lung volumes

2. Chest wall - kyphosis, scoliosis

• Stiffened chest wall
• ↑ work of breathing
• ↓ standard lung volumes

Pulmonary edema

• ⭐ Pulmonary edema - pathological accumulation of excess fluid in the lungs
• Pulmonary edema may occur under a number of different conditions

1. Increased hydrostatic pressure in the pulmonary capillaries
2. Increased permeability of the vascular endothelial cell or alveolar epithelial cell
3. Decreased oncotic pressure gradient (low plasma colloid oncotic pressure)
4. Impaired lymphatic drainage

Classification:

1. Cardiogenic

• Congestive heart failure
• Hearts inability to pump blood out which comes from pulmonary circulation due to left ventricular heart failure

2. Non-cardiogenic

• Build up of negative pressure in the lungs that ruptures blood capillaries and floods the alveoli
• Exogenous - causes dysfunction to epithelial cells of alveoli causing collapse → e.g toxic substance, aspiration in newborns
• Endogenous - affect the capillaries → e.g. sepsis, DIC, liver failure