LIPS-A: Lung Injury Prevention Study With Aspirin

Acute respiratory distress syndrome (ARDS) remains a life-threatening critical care syndrome characterized by alveolar-capillary membrane injury and hypoxemic respiratory failure. The median time to onset of ARDS is 2 days after hospital presentation. Therefore, the period between hospital presentation and the development of ARDS presents a brief window of opportunity for ARDS prevention. This was a multicenter, double-blind, placebo-controlled, parallel-group, Phase 2b, randomized clinical trial. Development of ARDS was defined by Berlin criteria (modified to require invasive mechanical ventilation) within 7 days of hospital admission. The first dose of study drug or placebo was administered within 24 hours after presentation to the hospital. Important co-interventions were standardized across sites using a web-based tool, Checklist for Lung Injury Prevention. Study participants were screened daily for receipt of mechanical ventilation and determination of the partial pressure of arterial oxygen (PaO2) or oxygen saturation to fraction of inspired oxygen ratio (SpO2:FIO2). If the participant's SpO2:FIO2 ratio was consistently below 315, hypoxemia was confirmed with measurement of arterial blood gas. Chest radiographs for all intubated patients with a SpO2:FIO2 of 300 or less were independently reviewed by both site investigator and a member of the trial's executive committee. Study participants who died or were discharged from the hospital before day 7 without meeting criteria for ARDS were adjudicated as not having ARDS.