Step 2 of A Two-step Trial to Evaluate the Effectiveness and Safety of Remimazolam Besylate for Sedation in ICU Patients

• Remimazolam besylate (Drug): 0\~2.0mg/kg/h
• Propofol (Drug): 0.3\~4.0mg/kg/h
• Remifentanil (Drug): 1.5\~12μg/kg/h

Primary outcomes

• Successful sedation [24 hours]: 70% of time in the target sedation range in participants without rescue sedation

Secondary outcomes

• The percentage of time in the target sedation range without rescue sedation [24 hours]: The percentage of time in the target sedation range without rescue sedation
• Number of patients needing rescue sedation [24 hours]: Whether participants need sedative drugs other than the study drug to re maintain targeted sedation level
• Number of patients needing repeated boluses of the study drug [24 hours]: Whether participants need repeated boluses of the study durg other than the loading dose to maintain targeted sedation level
• The amount of remifentanil in ug/kg/h [24 hours]: The amount of remifentanil in ug/kg/h used in each patient in both groups

Other outcomes

• Hypotension [24 hours]: Whether hypotension occurs in participants
• Delirium [24 hours]: Whether delirium occurs in participants

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

* Age ≥ 18 and ≤ 80 years
* Body mass index (BMI) ≥18 and ≤ 30 kg/m2
* Being Intubated and mechanically ventilated ≤48 hours before enrollment and expected to be on ventilator for at least 6 hours
* Requirement for light to moderate sedation (a Richmond agitation-sedation scale score of -2 to 1)

Exclusion Criteria:

* Refusal to be included
* Allergy or unsuitability to any composition of study drugs or remifentanil
* Living expectancy less than 48 hours
* Myasthenia gravis
* Status asthmaticus
* Abdominal compartment syndrome
* Serious hepatic dysfunction (CTP 10-15);
* Chronic kidney disease with glomerular filtration rate (GFR) < 29 ml/min/1.73m2
* Mean blood pressure less than 65 mm Hg or the need of a continuous infusion of norepinephrine at ≥0.5 ug/kg/min to maintain Mean blood pressure ≥ 65 mm Hg
* Possible requirement for surgery or bedside tracheostomy in 24 hours
* Possible requirement for renal replacement therapy in 24 hours
* Acute severe neurological disorder and any other condition interfering with sedation assessment
* Abuse of controlled substances or alcohol
* Pregnancy or lactation
* Inclusion in another interventional trial in the past 30 days
* Other conditions deemed unsuitable to be included

• Results publication: Yang X, Pan J, Gong X, Lv A, Liang F, Liu J, Li D, Fu S, Pan A, Yu L, Zhang L, Chen T, Zhan L, Qin B, Lin F, Xiong X, Zhu Y, He Z, Sun R, Sun T, Qian S, Wen D, Zou X, Qi H, Shu H, Song L, Wang C, Shang Y. Short-term light sedation with remimazolam besylate versus propofol in the ICU (SHOSREB): a multicentre, randomized, single-blind, controlled trial. Intensive Care Med. 2026 May;52(5):1001-1011. doi: 10.1007/s00134-026-08381-x. Epub 2026 Mar 31. PMID 41915173
• Results publication: Tang Y, Shu H, Ren L, Li R, Zou X, Qi H, Ouyang Y, Wu Y, Xu J, Fang X, Yang X, Shang Y. Remimazolam Besylate Versus Propofol for Short-Term Sedation in Critically Ill Patients Receiving Mechanical Ventilation: Protocol for a Multicenter Randomized Non-inferior Trial. Adv Ther. 2025 Aug;42(8):4081-4088. doi: 10.1007/s12325-025-03268-7. Epub 2025 Jun 10. PMID 40493335