Ventilatory management of acute lung injury and acute respiratory distress syndrome

Context  The acute lung injury and acute respiratory distress syndrome are critical illnesses associated with significant morbidity and mortality. Mechanical ventilation is the cornerstone of supportive therapy. However, despite several important advances, the optimal strategy for ventilation and adjunctive therapies for patients with acute lung injury and acute respiratory distress syndrome is still evolving. Evidence Acquisition  To identify reports of invasive ventilatory and adjunctive therapies in adult patients with acute lung injury and acute respiratory distress syndrome, we performed a systematic English-language literature search of MEDLINE (1966-2005) using the Medical Subject Heading respiratory distress syndrome, adult, and related text words, with emphasis on randomized controlled trials and meta-analyses. EMBASE and the Cochrane Central Register of Controlled Trials were similarly searched. The search yielded 1357 potential articles of which 53 were relevant to the study objectives and considered in this review. Evidence Synthesis  There is strong evidence to support the use of volume- and pressure-limited lung-protective ventilation in adult patients with acute lung injury and acute respiratory distress syndrome. The benefit of increased levels of positive end-expiratory pressure and recruitment maneuvers is uncertain and is being further evaluated in ongoing trials. Existing randomized controlled trials of alternative ventilation modes, such as high-frequency oscillation and adjunctive therapies, including inhaled nitric oxide and prone positioning demonstrate no significant survival advantage. However, they may have a role as rescue therapy for patients with acute respiratory distress syndrome with refractory life-threatening hypoxemia. Conclusions  Volume- and pressure-limited ventilation strategies should be used in managing adult acute lung injury and acute respiratory distress syndrome patients. Further research is needed to identify barriers to widespread adoption of this strategy, as well as the role of alternative ventilation modes and adjunctive therapies.