Ventilator-induced lung injury and implications for clinical management.

OBJECTIVE To review recent studies in pathogenesis and management of ventilator-induced lung injury. DATA SOURCES Articles and published reviews on ventilator-induced lung injury, barotrauma and acute lung injury. SUMMARY OF REVIEW This review summarises the important differences between clinically apparent 'barotrauma' and the more subtle changes in lung structure and function associated with ventilation. Of great importance is the understanding that as the underlying lung injury worsens, the degree of injury from mechanical ventilation increases. An inflammatory process results from mechanical stimuli and this may contribute to distant organ dysfunction. A great deal of knowledge has been obtained from the use of animal models, however, one must be cautious about extrapolating these findings directly to the clinical setting without the use of adequately designed clinical trials. Tidal volume reduction and higher levels of PEEP and recruitment manoeuvres should be employed given the available evidence. The use of high frequency techniques, surfactant therapy despite their past track record, may prove to be exciting 're-discoveries'. CONCLUSIONS Ventilator-induced lung injury is an iatrogenic disturbance that increases morbidity and mortality associated with acute respiratory distress syndrome. Tidal volume reduction and increased levels of PEEP have reduced inflammatory mediators and the mortality associated with ARDS.