Early Intravascular Events Are Associated with Development of Acute Respiratory Distress Syndrome. A Substudy of the LIPS-A Clinical Trial

Rationale: Acute respiratory distress syndrome (ARDS) is a devastating illness with limited therapeutic options. A better understanding of early biochemical and immunological events in ARDS could inform the development of new preventive and treatment strategies.Objectives: To determine select peripheral blood lipid mediator and leukocyte responses in patients at risk for ARDS.Methods: Patients at risk for ARDS were randomized as part of a multicenter, double-blind clinical trial of aspirin versus placebo (the LIPS-A [Lung Injury Prevention Study with Aspirin] trial; NCT01504867). Plasma thromboxane B2 (TXB2), aspirin-triggered lipoxin A4 (15-epi-LXA4, ATL), and peripheral blood leukocyte number and activation were determined on enrollment and after treatment with either aspirin or placebo.Measurements and Main Results: Thirty-three of 367 subjects (9.0%) developed ARDS after randomization. Baseline ATL levels, total monocyte counts, intermediate monocyte counts, and monocyte–platelet aggregates were assoc...