An evidence-based approach to acute respiratory distress syndrome.

We provide an evidence-based approach to managing patients with acute lung injury and acute respiratory distress syndrome (ARDS). We searched MEDLINE and the Cumulative Index to Nursing and Allied Health for randomized trials evaluating lung-protective ventilation strategies, inhaled nitric oxide, prone positioning, and late-phase corticosteroids for managing these patients, and for additional literature related to long-term follow-up of ARDS survivors. The results of our review suggest that pressure- and volume-limited ventilation, according to the ARDS Network protocol, can reduce mortality for patients with acute lung injury, and so may an "open lung" approach to mechanical ventilation. Those 2 strategies are currently being compared in 2 multicenter randomized trials. Although both inhaled nitric oxide therapy and prone positioning can produce dramatic acute improvements in oxygenation for some patients, there is no evidence that these interventions can benefit patients with respect to patient-important outcomes. Therefore it is unreasonable to be dogmatic about the role of inhaled nitric oxide and prone positioning in ARDS. The role of corticosteroids in the late phase of ARDS is unclear and remains a very important unanswered question. With respect to long-term follow-up, we found that pulmonary dysfunction is probably not a major source of morbidity for ARDS survivors, whereas neuropsychological dysfunction is prominent. Ongoing research may suggest interventions to improve the outcome of ARDS and of critical illness in general.