Mechanisms of pulmonary hypertension in chronic obstructive pulmonary disease
|Mechanisms of pulmonary hypertension in chronic obstructive pulmonary disease
Mechanisms of pulmonary hypertension in chronic obstructive pulmonary disease are as follows:
- Alveolar hypoxia is a potent stimulus for pulmonary vasoconstriction. Oxygen is one of the most potent pulmonary vasodilators.
- Hypercarbia due to carbon dioxide retention causes acidosis and consequent pulmonary hypertension.
- Mechanical effect of the high lung volume on pulmonary vessels causes increase in pulmonary arterial pressures.
- Loss of small vessels in the vascular bed in regions of lung destruction increases the total pulmonary vascular resistance and an associated increase in pulmonary arterial pressures.
- Polycythemia secondary to hypoxia increases the blood viscosity, which in turn increases the resistance to blood flow and an increase in the driving pressure.