Biotrauma and Ventilator-Induced Lung Injury

The pathophysiological mechanisms by which mechanical ventilation can contribute to lung injury, termed "ventilator-induced lung injury" (VILI), is increasingly well understood. "Biotrauma" describes the release of mediators by injurious ventilatory strategies, which can lead to lung and distal organ injury. Insights from preclinical models demonstrating that traditional high tidal volumes drove the inflammatory response helped lead to clinical trials demonstrating lower mortality in patients who underwent ventilation with a lower-tidal-volume strategy. Other approaches that minimize VILI, such as higher positive end-expiratory pressure, prone positioning, and neuromuscular blockade have each been demonstrated to decrease indices of activation of the inflammatory response. This review examines the evolution of our understanding of the mechanisms underlying VILI, particularly regarding biotrauma. We will assess evidence that ventilatory and other "adjunctive" strategies that decrease biotrauma offer great potential to minimize the adverse consequences of VILI and to improve the outcomes of patients with respiratory failure.