Reduced lung volumes

• Main respiratory problem post surgery is reduced lung volume (Functional Residual Capacity)!!!!
• Reasons for Reduced Lung Volumes (post thoracic or abdominal surgery):

  • Pain -> reduced tidal volume and impaired cough
  • Decreased mucociliary transport -> sputum plugging and atelectasis
  • Position during surgery and post-op period -> decreased functional residual capacity -> atelectasis
  • Absorption atelectasis if high FiO2 and hypoventilation
  • Immobility -> decreased tidal volume and functional residual capacity -> atelectasis
  • Distended abdomen -> diaphragmatic dysfunction
• Consequences of Reduced Lung Volumes:

  • Reduced compliance
  • Atelectasis
  • Reduced surface area for gas exchange
  • Hypoxaemia
  • Increased work of breath
  • Breathlessness