Efficacy and Safety of Remimazolam Besylate Versus Propofol for Sedation in Mechanically Ventilated ICU Patients

Inclusion Criteria: * Age ≥ 18 and ≤ 75 years; * Intubated and mechanically ventilated ≤96 hours before enrollment； * Expected to require continuous invasive ventilation and sedation ≥24 hours; * Requirement for light to moderate sedation (a RASS score of -3 to 0). Exclusion Criteria: * Body mass index (BMI) \<18 or \>30 kg/m2; * Acute severe neurological disorder and any other condition interfering with RASS assessment; * Systolic blood pressure less than 90 mm Hg after appropriate intravenous volume replacement and continuous infusions of 2 vasopressors; * Heart rate less than 50 beats/min; * Second- or third-degree heart block in the absence of a pacemaker; * Unstable angina; * Acute myocardial infarction; * Left ventricular ejection fraction less than 30%; * Contraindicate or allergic to study drugs; * Moribund state; * Acute hepatitis or serious hepatic dysfunction (Child-Pugh class C); * Chronic kidney disease with glomerular filtration rate (GFR) \< 60 ml/min/1.73m2; * Alcohol abuse; * Myasthenia gravis; * Pregnancy or lactation.