Aspirin shows no therapeutic potential in ARDS

In the treatment of patients with acute respiratory distress syndrome (ARDS), the use of aspirin improves neither oxygenation index nor other physiological outcomes, according to the results of a phase II study.

The study included ARDS patients from five intensive care units in the United Kingdom. They were randomized to receive enteral aspirin 75 mg or placebo for a maximum of 14 days, stratified by vasopressor requirement.

Due to slow recruitment, the trial was terminated prematurely, after the enrolment of 49 of a planned 60 patients. Of these, 24 were allocated to aspirin and 25 to placebo.

Compared with the placebo group, the aspirin group comprised more male patients (58.3 percent vs 40 percent), had a higher baseline APACHE II score (24.4 vs 22.0), and a lower vasopressor requirement (54.2 percent vs placebo 64 percent). Pneumonia was the main cause of ARDS, but the placebo group had more sepsis-induced ARDS than the aspirin group (20.8 percent vs 40 percent). However, the differences were said to likely represent a chance finding due to the lower-than-planned sample size.

The primary endpoint of oxygenation index at day 7 did not differ between the aspirin and placebo groups (unadjusted mean, 54.4 vs 42.4, respectively; mean difference, 12.0, 95 percent confidence interval [CI], –6.1 to 30.1; p=0.19).

Aspirin also had a null effect on the secondary outcomes, including other respiratory physiological markers. Likewise, there was no significant between-group difference in the number of adverse events that occurred (13 in each group; odds ratio, 1.04, 95 percent CI, 0.56–1.94; p=0.56).

The findings suggest that a larger trial of is not feasible in its current design.