Abstract
Sedation is crucial for managing mechanically ventilated intensive care unit (ICU) patients, but agents differ in their effects. Propofol, benzodiazepines and α₂-agonists are commonly used, yet their comparative impact remains unclear. This review searched OVID MEDLINE and Embase from January 2006 to June 2025 for randomised controlled trials in adult ICU patients. The primary outcome was duration of mechanical ventilation; secondary outcomes were ICU length of stay, delirium and mortality. Twenty-six trials (N = 4,993) were included. Dexmedetomidine significantly shortened mechanical ventilation (mean difference [MD] –0.60 days; 95 % CI –0.89 to –0.31), with larger effects versus midazolam (MD –1.25 days) and mixed comparators (MD –1.23 days), but not versus propofol (MD –0.34 days). ICU stay was also reduced (MD –0.94 days; 95 % CI –1.49 to –0.39). Delirium risk decreased (odds ratio [OR] 0.58; 95 % CI 0.38–0.87). No mortality difference was found. Dexmedetomidine is therefore associated with a modest but clinically meaningful reduction in ventilation time, ICU stay and delirium, particularly when compared with benzodiaze-pines, though benefits over propofol are less certain.