Aspirin as a Treatment for ARDS: A Randomized, Placebo-Controlled Clinical Trial.

BACKGROUND: There is no pharmacologic treatment for ARDS. Platelets play an important role in the pathophysiology of ARDS. Preclinical, observational, and clinically relevant models of ARDS indicate aspirin as a potential therapeutic option. RESEARCH QUESTION: Is enteral aspirin (75 mg, once daily) safe and effective in improving surrogate outcomes in adult patients with ARDS? STUDY DESIGN AND METHODS: This randomized, double-blind (patient and investigator), allocation-concealed, placebo-controlled phase 2 trial was conducted in five UK ICUs. Patients fulfilling the Berlin definition of ARDS were randomly assigned at a 1:1 ratio to receive enteral aspirin (75 mg) or placebo, for a maximum of 14 days, using a computer-generated randomization schedule, with variable block size, stratified by vasopressor requirement. The primary end point was oxygenation index (OI) on day 7. Secondary outcomes included safety parameters and other respiratory physiological markers. Analyses were by intention to treat. RESULTS: The trial was stopped early, due to slow recruitment, after 49 of a planned 60 patients were recruited. Twenty-four patients were allocated to aspirin and 25 to placebo. There was no significant difference in day 7 OI [aspirin group: unadjusted mean, 54.4 (SD 26.8); placebo group: 42.4 (SD 25); mean difference, 12.0; 95% CI, -6.1 to 30.1; P = .19]. Aspirin did not significantly impact the secondary outcomes. There was no difference in the number of adverse events between the groups (13 in each; OR, 1.04; 95% CI, 0.56-1.94; P = .56). INTERPRETATION: Aspirin was well tolerated but did not improve OI or other physiological outcomes; a larger trial is not feasible in its current design. TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT02326350; URL: www. CLINICALTRIALS: gov.

Effect of Lower Tidal Volume Ventilation Facilitated by Extracorporeal Carbon Dioxide Removal vs Standard Care Ventilation on 90-Day Mortality in Patients With Acute Hypoxemic Respiratory Failure: The REST Randomized Clinical Trial.

Importance: In patients who require mechanical ventilation for acute hypoxemic respiratory failure, further reduction in tidal volumes, compared with conventional low tidal volume ventilation, may improve outcomes. Objective: To determine whether lower tidal volume mechanical ventilation using extracorporeal carbon dioxide removal improves outcomes in patients with acute hypoxemic respiratory failure. Design, Setting, and Participants: This multicenter, randomized, allocation-concealed, open-label, pragmatic clinical trial enrolled 412 adult patients receiving mechanical ventilation for acute hypoxemic respiratory failure, of a planned sample size of 1120, between May 2016 and December 2019 from 51 intensive care units in the UK. Follow-up ended on March 11, 2020. Interventions: Participants were randomized to receive lower tidal volume ventilation facilitated by extracorporeal carbon dioxide removal for at least 48 hours (n = 202) or standard care with conventional low tidal volume ventilation (n = 210). Main Outcomes and Measures: The primary outcome was all-cause mortality 90 days after randomization. Prespecified secondary outcomes included ventilator-free days at day 28 and adverse event rates. Results: Among 412 patients who were randomized (mean age, 59 years; 143 [35%] women), 405 (98%) completed the trial. The trial was stopped early because of futility and feasibility following recommendations from the data monitoring and ethics committee. The 90-day mortality rate was 41.5% in the lower tidal volume ventilation with extracorporeal carbon dioxide removal group vs 39.5% in the standard care group (risk ratio, 1.05 [95% CI, 0.83-1.33]; difference, 2.0% [95% CI, -7.6% to 11.5%]; P = .68). There were significantly fewer mean ventilator-free days in the extracorporeal carbon dioxide removal group compared with the standard care group (7.1 [95% CI, 5.9-8.3] vs 9.2 [95% CI, 7.9-10.4] days; mean difference, -2.1 [95% CI, -3.8 to -0.3]; P = .02). Serious adverse events were reported for 62 patients (31%) in the extracorporeal carbon dioxide removal group and 18 (9%) in the standard care group, including intracranial hemorrhage in 9 patients (4.5%) vs 0 (0%) and bleeding at other sites in 6 (3.0%) vs 1 (0.5%) in the extracorporeal carbon dioxide removal group vs the control group. Overall, 21 patients experienced 22 serious adverse events related to the study device. Conclusions and Relevance: Among patients with acute hypoxemic respiratory failure, the use of extracorporeal carbon dioxide removal to facilitate lower tidal volume mechanical ventilation, compared with conventional low tidal volume mechanical ventilation, did not significantly reduce 90-day mortality. However, due to early termination, the study may have been underpowered to detect a clinically important difference. Trial Registration: ClinicalTrials.gov Identifier: NCT02654327.