Dose Finding Study of Remimazolam for Laryngeal Mask Airway Insertion

Study Overview
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Brief Summary
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Laryngeal mask airways (LMA) are widely used in patients receiving general anesthesia and are known to have the following advantages over the endotracheal tube: lower incidence of postoperative sore throat, lower incidence of cough during emergence, and lower incidence of postoperative vomiting. Although LMAs can be inserted without the use of muscle relaxants, a sufficient depth of anesthesia is necessary for placement. Remimazolam is a newer anesthetic that is ultra-short acting with a rapid onset and short context-sensitive half-life allowing for fast recovery. However, the dose of remimazolam needed for LMA insertion without muscle relaxants is not well known. This dose-finding study aims to find the ED50 and ED95 of a single bolus dose of remimazolam for LMA insertion without muscle relaxants in adult patients. This is an interventional study done in a single group using the Dixon's up-and-down method which requires at least six success/failure pairs in the same direction. The primary endpoint of this study is to investigate the dose of remimazolam associated with 50% (ED50) and 95% (ED95) probability for adequate depth of anesthesia for LMA insertion without muscle relaxants. The beginning dose of remimazolam is 0.3 mg/kg, and when LMA insertion is successful, the dose will be decreased by 0.05 mg/kg in the next patient. When LMA insertion is unsuccessful (failed), the dose will be increased by 0.05 mg/kg in the next patient. Successful LMA insertion is defined as symmetrical chest wall movement and square-wave capnographic traces observed with manual ventilation.

Official Title
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Dose Finding Study of Remimazolam for Laryngeal Mask Airway Insertion

Conditions
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Orthopedic Surgery

Intervention / Treatment
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* Drug: Remimazolam bolus does administration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients aged 19 65 year ASA class I III Patients scheduled for orthopedic surgery under general anesthesia and eligible for LMA use. Exclusion Criteria: Patient refusal Patients unable to read consent form Anticipated difficult mask ventilation Active URI or uncontrolled asthma Pneumonia Risk of aspiration such as GERD History of allergies to benzodiazepines Decreased liver or kidney function Pregnant or breastfeeding patients BMI > 30kg/m2 History of substance abuse/addiction

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Remimazolam<br>A bolus dose of remimazolam is administered to facilitate LMA insertion | Drug: Remimazolam bolus does administration<br>* The beginning dose of remimazolam is 0.3 mg/kg, and when LMA insertion is successful, the dose will be decreased by 0.05 mg/kg in the next patient. When LMA insertion is unsuccessful (failed), the dose will be increased by 0.05 mg/kg in the next patient.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dose of remimazolam associated with 50% (ED50) probability for adequate depth of anesthesia for LMA insertion without muscle relaxants. | The primary outcome of this study will be determined based on the data of success or failure of LMA insertion at predetermined doses of remimazolam. Successful LMA insertion is defined as symmetrical chest wall movement and square-wave capnographic traces observed with manual ventilation which will be assessed immediately after LMA insertion attempt. | During procedure (Immediately after LMA insertion attempt) |