Inhaled Sedation in Acute Respiratory Distress Syndrome

Whether the use of inhaled or intravenous sedation affects outcomes differentially in mechanically ventilated adults with acute respiratory distress syndrome (ARDS) is unknown. To determine the efficacy and safety of inhaled sevoflurane compared with intravenous propofol for sedation in patients with ARDS. Phase 3 randomized, open-label, assessor-blinded clinical trial conducted from May 2020 to October 2023 with 90-day follow-up. Adults with early moderate to severe ARDS (defined by a ratio of Pao2 to the fraction of inspired oxygen of <150 mm Hg with a positive end-expiratory pressure of ≥8 cm H2O) were enrolled in 37 French intensive care units. Patients were randomized to a strategy of inhaled sedation with sevoflurane (intervention group) or to a strategy of intravenous sedation with propofol (control group) for up to 7 days. The primary end point was the number of ventilator-free days at 28 days; the key secondary end point was 90-day survival. Of 687 patients enrolled (mean [SD] age, 65 [12] years; 30% female), 346 were randomized to sevoflurane and 341 to propofol. The median total duration of sedation was 7 days (IQR, 4 to 7) in both groups. The number of ventilator-free days through day 28 was 0.0 days (IQR, 0.0 to 11.9) in the sevoflurane group and 0.0 days (IQR, 0.0 to 18.7) in the propofol group (median difference, -2.1 [95% CI, -3.6 to -0.7]; standardized hazard ratio, 0.76 [95% CI, 0.50 to 0.97]). The 90-day survival rates were 47.1% and 55.7% in the sevoflurane and propofol groups, respectively (hazard ratio, 1.31 [95% CI, 1.05 to 1.62]). Among 4 secondary outcomes, sevoflurane was associated with higher 7-day mortality (19.4% vs 13.5%, respectively; relative risk, 1.44 [95% CI, 1.02 to 2.03]) and fewer intensive care unit-free days through day 28 (median, 0.0 [IQR, 0.0 to 6.0] vs 0.0 [IQR, 0.0 to 15.0]; median difference, -2.5 [95% CI, -3.7 to -1.4]) compared with propofol. Among patients with moderate to severe ARDS, inhaled sedation with sevoflurane resulted in fewer ventilator-free days at day 28 and lower 90-day survival than sedation with propofol. ClinicalTrials.gov Identifier: NCT04235608.