Mechanical ventilation is one of the most frequently performed interventions in intensive care. It can be life-saving in acute respiratory failure, but it carries the potential for significant harm if not managed carefully. The main hazard is ventilator-induced lung injury (VILI) — damage to the lung parenchyma caused by the mechanical ventilation itself, rather than the underlying disease.

The four components of VILI are barotrauma (damage from excessive airway pressures, particularly plateau pressure above 30 cmH2O), volutrauma (damage from excessive tidal volumes, particularly above 8 mL/kg in ARDS), atelectrauma (damage from cyclical alveolar collapse and reopening with each breath, prevented by adequate PEEP), and oxygen toxicity (damage from prolonged exposure to high FiO2 generating free radicals).

Understanding VILI is the conceptual foundation of all ventilator management: every decision about settings should be framed by the question — ‘Is this causing more benefit than harm to the lungs?’