Comparison of the effects of esketamine/midazolam and remifentanil/midazolam on respiratory mechanics in mechanically ventilated patients with acute respiratory distress syndrome

Abstract Background Esketamine exerts analgesic effects and has pharmacological properties of bronchodilation and elevation of mean arterial pressure, making it an interesting analgesic agent for patients with ARDS. Therefore, we conducted a randomized controlled trial comparing the effects of esketamine/midazolam and remifentanil/midazolam on respiratory mechanics and oxygenation in mechanically ventilated patients with ARDS. Methods In this prospective, randomized, controlled study, patients with ARDS who were undergoing mechanical ventilation were randomly assigned to receive either remifentanil/midazolam (n = 25) or esketamine/midazolam (n = 25). Both groups maintained equivalent levels of sedation and analgesia. The primary outcomes were airway resistance (Raw) and static respiratory system compliance (Cst) at 24, 48, and 72 h post-medication administration. Plateau Pressure (Pplat), peak airway pressure (Ppeak), hemodynamic parameters, mechanical ventilation duration, and ICU length of stay were also recorded. Results Cst at 72 h post-medication in esketamine group (49.8 ± 13.8) was higher than that in control group (42.4 ± 11.9) (P < 0.05). There was no significant difference in Raw at 24 h, 48 h and 72 h post-medication between the two groups (P > 0.05). At 72 h post-medication, both Pplat and Ppeak in the esketamine group [(15.6 ± 3.1); (25.7 ± 3.8)] were significantly lower than those in the control group[(17.7 ± 4.2); (28.5 ± 4.7)] (P < 0.05). Additionally, the esketamine group [(256.6 ± 89.1); (266.4 ± 88.4); (284.92 ± 84.45)] demonstrated significantly higher PaO₂/FiO₂ ratios compared to the control group [(208.7 ± 61.5);(219.52 ± 61.28); (222.00 ± 68.54)] at all measured time points (P < 0.05). MAP and heart rate were higher in the esketamine group than in the control group, while cumulative doses of vasoactive drugs were comparatively lower in the esketamine group. The duration of mechanical ventilation and ICU length of stay did not-differ (P > 0.05). Conclusion Esketamine/midazolam leads to improved in Cst and PaO2/FiO2 ratio compared to remifentanil/midazolam in mechanically ventilated patients with ARDS. Clinical trial registration This study was registered at Chinese Clinical Trial Registry (ChiCTR2300070733) on April 21, 2023. URL: https://www.chictr.org.cn/ .