Exploring the association between dexmedetomidine and all-cause mortality in mechanically ventilated patients with sepsis through propensity score matching analysis and machine learning algorithms: a MIMIC-IV retrospective study.

Background: Sepsis carries high ICU mortality globally, often requiring sedated mechanical ventilation. While some studies suggest dexmedetomidine improves survival in these patients, others contradict this finding. This study evaluates dexmedetomidine's survival benefit and sedation value for ventilated sepsis cases. Methods: This retrospective cohort study utilized the MIMIC-IV database and eICU-CRD to analyze mechanically ventilated septic patients. Propensity score matching was employed to balance covariates. Machine learning algorithms were applied to validate dexmedetomidine's role in predicting mortality. Results: A propensity score matching analysis was performed for 5176 pairs of patients. The use of dexmedetomidine was associated with a reduced risk of 28-day mortality (13.39% vs. 19.84%, HR: 0.595, Conclusions: Dexmedetomidine use significantly reduces short-term mortality in mechanically ventilated patients with sepsis but prolongs the hospital and ICU length of stay (LOS) and duration of mechanical ventilation. Administering dexmedetomidine within 48 hours and maintaining an infusion rate at or below 0.6 μg/kg/h appears to be more beneficial. Moreover, dexmedetomidine use strongly influences mortality in these patients.