Clinical trial design in acute lung injury--issues and controversies.

The evolution of scientific investigation in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is replete with examples of effective bench-to-bedside transitions, pioneering research methodology, and international collaboration. This article highlights for clinicians a selection of challenges and controversies of clinical trial design in ALI and ARDS. A section on Patient Selection highlights controversial trade-offs between homogeneous and heterogeneous study populations. A section on Clinical Protocols covers blinding, process-of-care interventions, usual-care control groups, and standardized protocols for adjunctive care. The third section discusses the quest for ideal Study Outcomes. The final section presents Interpretation Controversies, such as early stopping of clinical trials.