Aspirin for the Treatment of Acute Respiratory Distress Syndrome

Aspirin in palm of hand
Aspirin in palm of hand
The STAR clinical trial explored the safety and efficacy of once-daily aspirin for improving surrogate outcomes of acute respiratory distress syndrome.

Aspirin is well tolerated in patients with acute respiratory distress syndrome (ARDS) but did not appear to improve the oxygenation index (OI) or other physiological outcomes associated with ARDS. These clinical trial findings were recently reported in an article published in CHEST.

While there is no pharmacological treatment for ARDS, it appears that platelets may play an important role in its pathophysiology. Therefore, some data suggest that aspirin may be a potential therapeutic option.

The STAR trial ( Identifier: NCT02326350), a randomized, double blind, placebo-controlled phase 2 study, was designed to determine whether daily aspirin is safe and effective in improving surrogate outcomes in adult patients with ARDS. Study researchers at 5 intensive care units in the United Kingdom randomly assigned ARDS patients to receive enteral aspirin 75 mg or placebo for a maximum of 14 days. The primary endpoint was the Oxygen Index (OI) at day 7, and secondary outcomes included safety parameters and other respiratory physiological markers.

Due to strict exclusion criteria, only 49 of a planned 60 patients were recruited for the trial, with 24 patients in the aspirin group and 25 in the placebo group. The researchers found that there was no significant difference in day 7 OI (unadjusted mean 54.4 in the aspirin group, 42.4 in the placebo group; mean difference 12.0, P=.19), and that aspirin did not significantly impact the secondary outcomes. They also found that there was no difference in the number of adverse events between the groups (13 in each, odds ratio 1.04, 95% CI, 0.56-1.94, P=.56).

Notably, recruitment for this trial was halted when early evidence suggested that the time needed to recruit additional participants would not significantly alter the trial’s outcome.  Researchers concluded, “Aspirin appeared to be well tolerated in patients with ARDS.” They further noted that “The feasibility of a large interventional study of aspirin in ARDS is questionable, unless further studies are less restrictive in their exclusion criteria.”


Toner P, Boyle AJ, McNamee JJ, et al. Aspirin as a treatment for acute respiratory distress syndrome: a randomised placebo controlled clinical trial. CHEST. Published online November 2, 2021. doi:10.1016/j.chest.2021.11.006