Update on ARDS: Beyond the Low Tidal Volume

In 2000, the Acute Respiratory Distress Syndrome (ARDS) network1 published the results of a landmark trial in which a specific therapy was found to improve survival in patients with ARDS. This was the first trial to demonstrate an improvement in mortality since the original description of the syndrome over 30 years earlier. In 1967, Ashbaugh et al described 12 patients with “acute respiratory distress, cyanosis refractory to oxygen therapy, decreased lung compliance, and diffuse infiltrates evident on the chest radiograph.”2 These patients were so difficult to oxygenate that the term “adult respiratory distress syndrome” was used to describe their condition, analogous to the respiratory distress syndrome seen in premature infants with hyaline membrane disease. These physicians also noted that oxygenation was improved by the use of positive endexpiratory pressure (PEEP). Nonetheless, the outcome was poor because 7 of the 12 patients died. Since the original description, our understanding of the epidemiology and clinical features of ARDS has evolved, ultimately resulting in the ARDSnet trial that demonstrated an improvement in survival with low tidal volumes.1 As we will show in the following review, there has been a significant amount of progress in our understanding and treatment of ARDS since the publication of this pivotal trial.