Ventilator-induced lung injury

Mechanical ventilation has become essential for the support of critically ill patients; however, it can cause ventilator-induced lung injury (VILI) or aggravate ventilator-associated lung injury (VALI), contributing to the high mortality rates observed in acute respiratory distress syndrome. This chapter discusses the mechanisms leading to VILI/VALI, the diagnostic procedures of early detection and how to prevent it.The clinical relevance of low lung volume injury and the application of high positive end-expiratory pressure levels remain debatable. Furthermore, researchers were not successful in transferring the measurement of inflammatory mediators during VILI/VALI from bench to bedside. Therefore, the following issues still require elucidation: 1) the best ventilator strategy to be adopted; 2) which ventilator parameters should be managed; 3) how to monitor VILI/VALI (arterial blood gases, lung mechanics, proinflammatory mediators); 4) the role of imaging (computed tomography scan, lung ultrasound and positron emission tomography; and 5) how to prevent VILI/VALI (new ventilatory and pharmacological strategies).