[Acute respiratory distress syndrome--treatments today and tomorrow]

Acute Respiratory Distress Syndrome (ARDS) is a life threatening condition. There are several randomized placebo controlled trials (RCT) that tested ventilated and non-ventilated patient managements. Among them, only ARMA trial that compared mortality and ventilator free-days between low tidal volume ventilation and conventional ventilation (6 and 12 ml x kg(-1) predicted body weight, respectively) showed differences (31.0% vs., 39.8%, P = 0.007 and 12 +/- 11 vs. 10 +/- 11 days, P = 0.007, respectively). The ALVEOLI trial testing high PEEP failed to show any benefit over the low tidal volume ventilation as control. Prone positioning may temporarily improve oxygenation, but does not affect mortality. High frequency oscillatory ventilation does not show strong evidence for mortality reduction over low tidal volume ventilation. Conservative strategy of fluid management after shock state increased ventilator-free days and ICU-free days without increasing adverse effects. Corticosteroids have been controversial. Methylprednisolone iv administration starting between 7 and 13 days of the onset of ARDS increased the number of ventilator-free days and shock-free days; whereas, methylprednisolone treatment starting more than two weeks after the onset of ARDS increased the risk of death. There are no RCTs that positively showed the improvement in mortality by using any therapeutic agent. Based on basic science studies, molecules that enhance epithelial and endothelial cell proliferation and the therapies targeting on septic pathophysiology would be the target for future strategies.