Ventilator-induced lung injury (VILI)

Definition

Every positive pressure breath causes cyclical inflation of alveoli followed by deflation. The resulting damage to alveoli occurs due to these process called VILI.

Causes:

• distending forces from the tidal volume, termed ‘volutrauma’
• the pressure used to inflate the lung, referred to as ‘barotrauma’,
• alveoli collapsing at the end of expiration, called ‘atelectotrauma’
• the release of inflammatory cytokines in response to cyclical distension, called ‘biotrauma’

Strategies that may reduce the incidence and severity of VILI include:

• Permissive hypercapnia 
• Open lung ventilation
• Paralysis