The purpose of this study is to evaluate the efficacy and safety of remimazolam besylate compared to propofol for sedation in critically ill patients with deep sedation.

This is a single-center, prospective, randomized, controlled study using remimazolam besylate and propofol for sedation in critically ill patients with deep sedation. Subjects are randomized to remimazolam group and propofol group in a 1:1 ratio. Remifentanil is administered as the analgesic. Efficacy and safety profiles of remimazolam besylate are to be evaluated.

Inclusion Criteria:

• Age ≥ 18 and ≤ 80 years;
• Expected to require deep sedation ≥8 hours;
• Requirement for deep sedation (a Narcotrend index between 13 and 64).

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;
• Expected to have a general anesthesia within 8 hours;
• Pregnancy or lactation.