Mechanical Ventilation


  • Improve gas exchange: ↑ oxygenation, ↑ alveolar vent and/or reverse acute resp acidosis
  • Relieve respiratory distress: ↓ work of breathing (can account for up to 50% of total O 2 consumption), ↓ respiratory muscle fatigue
  • Apnea, airway protection, pulmonary toilet

Supportive Strategies Prior to Intub. or After Extub.

Oxygen Delivery Systems (Lancet 2016;387:1867)
System or Device O2 Flowa FiO2 Range & Comments
Low-flow nasal cannula 1–6 24–40%, 1L adds ~3% FiO2
Standard face mask 5–10 35–50%, minimum 5 L/min
Partial rebreather mask