Sedation During Endoscopy Using Remimazolam: Efficacy in a Novel Exploration (SERENE)

Sedation During Endoscopy Using Remimazolam: Efficacy in a Novel Exploration (SERENE)

This study is a pragmatic, randomized controlled pilot trial comparing remimazolam with propofol for endoscopic procedures, designed to assess the feasibility and clinical outcomes associated with implementing a pragmatic randomized trial of sedation practices in the endoscopy setting.

Study Overview

• Status: Active, not recruiting
• Conditions: Anesthesia; Endoscopy; Sedation
• Intervention / Treatment: Drug: Remimazolam; Drug: Propofol

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Phase 3

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02214
      • Massachusetts General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Aged 18 years of age or older
• Planned endoscopic procedure
• American Society of Anesthesiologists (ASA) Physical Status I to III

Exclusion Criteria:

• Planned tracheal intubation
• Procedure length anticipated to exceed 45 minutes
• Previously participated in the trial
• Pregnant (defined as a positive test using pre-procedural clinical testing performed as part of their routine care) or breastfeeding
• Allergy or hypersensitivity to one of the study medications
• Blind, deaf, or unable to communicate in English
• Co-enrollment in other interventional studies that, in the opinion of the site investigator and/or their delegate, might interfere with study participation, collection, or interpretation of the study data

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Arm Title: Remimazolam Sedation; Participants randomized to this arm will receive remimazolam 0.20 mg/kg for procedural sedation. The maximum initial bolus will be 15 mg, with additional doses administered in 2.5 mg increments as needed to maintain adequate sedation. Intravenous fentanyl (25-100 mcg) may be administered as an adjunct per clinician judgement. This dosing strategy reflects the institution's standard-of-care approach to remimazolam-based sedation.	Drug: Remimazolam; Remimazolam will be administered at 0.20 mg/kg for procedural sedation. The maximum initial bolus is 15 mg, with additional 2.5 mg doses given as needed to maintain sedation. Intravenous fentanyl (25-100 mcg) may be used adjunctively per clinician judgement; Other Names: Byfavo
Active Comparator: Propofol Sedation; Participants randomized to this arm will receive propofol up to 1.5 mg/kg as the initial bolus, followed by intermittent boluses of 10-40 mg according to routine clinical practice. Intravenous fentanyl (25-100 mcg) may be administered as an adjunct per clinician judgement. This regimen reflects the institution's standard-of-care approach to propofol-based sedation.	Drug: Propofol; Propofol will be administered with an initial bolus of up to 1.5 mg/kg, followed by intermittent 10-40 mg boluses according to routine clinical practice. Intravenous fentanyl (25-100 mcg) may be used adjunctively per clinician judgement.; Other Names: Diprivan

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Patients Meeting Inclusion/Exclusion Criteria	Counts the number of patients screened who meet all prespecified inclusion and exclusion criteria for trial eligibility.	From initiation of screening through end of study enrollment period.
Number of Patients Consented	Total number of eligible patients who provide informed consent to participate in the study.	From initiation of recruitment through end of study enrollment period.
Number of Patients Receiving the Randomized Intervention Per Protocol	Number of consented participants who are successfully randomized and receive their assigned sedation intervention according to the study protocol without major deviations.	From randomization through completion of the endoscopic procedure.
Number of Completed Questionnaires	Total number of study-related questionnaires completed by participants at the designated assessment time points, used to evaluate feasibility and acceptability of study procedures.	At the end of the procedure and at the immediate post-procedure assessment.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence and Duration of Adverse Clinical Events	Incidence and duration of predefined adverse clinical events, including respiratory insufficiency, hypoxemia, hypotension, and bradycardia, occurring during the procedure.	From induction of sedation through end of the procedure
Procedural Success	Proportion of procedures completed successfully, defined as full completion of the planned endoscopic procedure with the patient maintaining adequate spontaneous ventilation throughout.	From induction of sedation through end of the procedure
Patient Satisfaction	Patient-reported satisfaction with the procedural sedation experience, assessed using a standardized post-procedure satisfaction questionnaire.	At the immediate post-procedure assessment
Provider Satisfaction	Satisfaction ratings from nurses, endoscopists, and anesthesiologists regarding the sedation process, collected using standardized provider questionnaire instruments.	Immediately after procedure completion
Procedure Duration	Total time from procedure start (scope insertion) to procedure end (scope removal), recorded in minutes.	From the start of the procedure through the end of the procedure
Post Anesthesia Care Unit Length of Stay	Time from the end of the endoscopic procedure to achievement of standardized post-anesthesia care unit discharge criteria.	Perioperative/Periprocedural
Time From Induction of Sedation to Procedure Start	Interval between administration of the initial sedation dose and the start of the endoscopic procedure (scope insertion).	From induction of sedation to procedure start
Richmond Agitation-Sedation Scale (RASS) Scores	Sedation depth assessed using repeated RASS measurements at prespecified intervals throughout the procedure.	Repeated measures assessed from induction of sedation through end of the procedure
Oxygen Saturation	Continuous or intermittent oxygen saturation (SpO₂) measurements collected at prespecified intervals during the procedure.	Repeated measures assessed from induction of sedation through end of the procedure
Blood Pressure Measurements	Repeated assessments of systolic, diastolic, and mean arterial blood pressure at prespecified intervals during the procedure.	Repeated measures assessed from induction of sedation through end of the procedure
Unplanned Conversion to General Anesthesia or Use of Non-Study Sedative	Number of cases requiring conversion to general anesthesia or administration of any sedative agent outside the assigned study drug protocol	From sedation induction through end of procedure.
Total Fentanyl Dose Administered	Cumulative dose of intravenous fentanyl administered as an adjunct to sedation during the procedure.	From induction of sedation to procedure end

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital
• Investigators: Principal Investigator: Oluwaseun Johnson-Akeju, MD, Massachusetts General Hospital

Study record dates

Study Major Dates

• Study Start (Actual): March 3, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2026

Study Registration Dates

• First Submitted: November 26, 2025
• First Submitted That Met QC Criteria: December 5, 2025
• First Posted (Actual): December 8, 2025

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 20, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Organic Chemicals; Hydrocarbons; Hydrocarbons, Cyclic; Hydrocarbons, Aromatic; Phenols; Benzene Derivatives; Propofol; remimazolam
• Other Study ID Numbers: 2025P002893

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes