Adjunctive therapy with azithromycin for moderate and severe acute respiratory distress syndrome: a retrospective, propensity score-matching analysis of prospectively collected data at a single center.

Effective pharmacological therapy has not been established for patients with acute respiratory distress syndrome (ARDS). Macrolides are antibiotics with potent immunomodulatory and anti-inflammatory effects that may be beneficial in ARDS treatment. The objective of this study was to determine the adjunctive effect of azithromycin on survival for patients with ARDS. This single-center, retrospective cohort evaluation of hospitalized patients with moderate or severe ARDS was conducted to assess the impact of intravenous azithromycin on clinical outcomes using a propensity score analysis. All data were collected prospectively as part of ongoing research on the utility of high-resolution computed tomography in ARDS. The primary outcome was 90-day mortality, and the secondary analysis assessed the effect of azithromycin on time to successful discontinuation of mechanical ventilation and 28-day mortality. Of 191 eligible patients with severe or moderate ARDS, 62 were treated with azithromycin. The 62 patients treated with azithromycin and 62 not treated with azithromycin were matched and analysed. Azithromycin use was associated with a statistically significant improvement in 90-day survival rate (Hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.27-0.87; P = 0.015) and a shorter time to successful discontinuation of mechanical ventilation (HR, 1.74; 95% CI, 1.07-2.81; P = 0.026). The 28-day mortality rate tended to be higher in the azithromycin cohort than in the non-azithromycin cohort, but this was not statistically significant. Adjunctive intravenous azithromycin therapy was effective in patients with moderate or severe ARDS. Further prospective randomized controlled trials are needed to confirm this result.