ED50 of Remimazolam for Anesthesia Induction in Frail Elderly Patients

March 8, 2026 updated by: Yanjie Yang, The First Hospital of Hebei Medical University

Significantly Reduced Median Effective Dose (ED50) of Remimazolam for Anesthesia Induction in Frail Elderly Patients: A Prospective Dose-Finding Clinical Trial With Respiratory Volume Monitoring

This study aimed to determine the median effective dose (ED50) of remimazolam for loss of consciousness (LOC) in elderly and frail elderly patients using the Dixon up-and-down method, while utilizing a novel Respiratory Volume Monitor (RVM) to detect subclinical respiratory depression.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The physiological decline associated with frailty in elderly patients presents significant challenges for anesthesia induction. Remimazolam tosilate, an ultra-short-acting benzodiazepine, offers a promising safety profile, yet its optimal dosing in frail populations remains undefined. This prospective, up-and-down sequential allocation trial was conducted at the Second Hospital of Hebei Medical University. 58 patients aged ≥65 years undergoing elective surgery were stratified into two groups: an Elderly Group (Clinical Frailty Scale [CFS] < 5) and a Frail Elderly Group (CFS ≥ 5). The initial remimazolam induction dose was set at 0.15 mg/kg for the elderly group and 0.13 mg/kg for the frail group, with dose adjustments based on the previous patient's response. A non-invasive RVM was employed to continuously monitor Tidal Volume (VT) and detect early hypoventilation.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
58

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
    • Hebei
      • Shijiazhuang, Hebei, China, 050000
        • Second Hospital of Hebei Medical University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Aged ≥65 years;
  • Scheduled for elective surgery under general anesthesia with endotracheal intubation;
  • American Society of Anesthesiologists (ASA) physical status II or III;
  • Body Mass Index (BMI) between 18 and 30 kg/m².

Exclusion Criteria:

  • Known allergy to benzodiazepines;
  • History of severe respiratory or cardiovascular disease (e.g., acute heart failure, severe COPD);
  • Long-term use of sedatives, analgesics, or alcohol abuse;
  • Known neuromuscular disorders (e.g., myasthenia gravis);
  • Inability to communicate for sedation assessment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Elderly Group (Non-Frail)
Patients with a Clinical Frailty Scale (CFS) score < 5.
Drug: Remimazolam Tosilate
The initial induction dose was set at 0.15 mg/kg administered as a single intravenous bolus over 30 seconds. The dose adjustment gradient for consecutive patients was 0.02 mg/kg based on the Dixon up-and-down method.
Drug: Remimazolam Tosilate
The initial induction dose was set at 0.13 mg/kg administered as a single intravenous bolus over 30 seconds. The dose adjustment gradient for consecutive patients was 0.01 mg/kg based on the Dixon up-and-down method.
Experimental: Frail Elderly Group
Patients with a Clinical Frailty Scale (CFS) score ≥ 5.
Drug: Remimazolam Tosilate
The initial induction dose was set at 0.15 mg/kg administered as a single intravenous bolus over 30 seconds. The dose adjustment gradient for consecutive patients was 0.02 mg/kg based on the Dixon up-and-down method.
Drug: Remimazolam Tosilate
The initial induction dose was set at 0.13 mg/kg administered as a single intravenous bolus over 30 seconds. The dose adjustment gradient for consecutive patients was 0.01 mg/kg based on the Dixon up-and-down method.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Sedation Success (Loss of Consciousness)
Time Frame: up to 2 minutes
Defined as the achievement of Loss of Consciousness (LOC) confirmed by loss of eyelash reflex, no response to verbal commands, Ramsay Sedation Score ≥ 5, and MOAA/S score < 1.
up to 2 minutes

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Median Effective Dose (ED50) of Remimazolam
Time Frame: Perioperative/Periprocedural
The ED50 calculated via probit analysis based on the Dixon up-and-down sequential allocation method.
Perioperative/Periprocedural
Changes in Tidal Volume (VT)
Time Frame: Baseline, 30 seconds, 60 seconds, 90 seconds, and up to 120 seconds post-administration
Continuous assessment of spontaneous Tidal Volume (VT) utilizing a non-invasive Respiratory Volume Monitor (RVM) to evaluate subclinical respiratory depression.
Baseline, 30 seconds, 60 seconds, 90 seconds, and up to 120 seconds post-administration
Mean Arterial Pressure (MAP)
Time Frame: Baseline and up to 2 minutes post-administration
Changes in Mean Arterial Pressure (MAP) during the induction period, measured in mmHg.
Baseline and up to 2 minutes post-administration
Heart Rate (HR)
Time Frame: Baseline and up to 2 minutes post-administration
Changes in Heart Rate (HR) during the induction period, measured in beats per minute.
Baseline and up to 2 minutes post-administration

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
The First Hospital of Hebei Medical University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 1, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 30, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 30, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 1, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 8, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 12, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 12, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 8, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2025-R031

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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