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:

  1. Alveolar hypoxia is a potent stimulus for pulmonary vasoconstriction. Oxygen is one of the most potent pulmonary vasodilators.
  2. Hypercarbia due to carbon dioxide retention causes acidosis and consequent pulmonary hypertension.
  3. Mechanical effect of the high lung volume on pulmonary vessels causes increase in pulmonary arterial pressures.
  4. 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.
  5. Polycythemia secondary to hypoxia increases the blood viscosity, which in turn increases the resistance to blood flow and an increase in the driving pressure.