Rocuronium and Supramaximal Stimulation

Study Overview
=================
Brief Summary
-----------------
To shorten induction time, some anesthesiologist gives a priming dose of muscle relaxant before starting Neuromuscular Transmission monitor (NMT). To properly evaluate neuromuscular function during the surgury, baseline supramaximal stimulation of the monitored nerve is mandatory. Not knowing if the priming dose of muscle relaxant affects the supramaximal stimulation current setting, The investigators designed this study to find out.

Detailed Description
-----------------
The NMT monitor module automatically determines the current needed for the supramaximal stimulus, and maintains this current throughout the procedure. The supramaximal current is the current above which there is no increase in the evoked muscle response. At this stimulus current, all motor units are firing in response to nerve stimulation. According to previous studies, the current was significantly increased in the presence of edema and peripheral neuropathy. In this study, the route of administration, dosage, dosage regimen, and treatment period are basically the same as the investigators anesthesia department's routine procedure for general anesthesia. The difference will be the time the investigators set between the priming dose to final dose of rocuronium is 2 minutes. The investigators use 2 minutes as the peak effect of rocuronium is 105±36S. To properly evaluate neuromuscular blockade during the surgery, baseline supramaximal stimulation of the monitored nerve is mandatory. Not knowing if the priming dose of muscle relaxant affects the supramaximal stimulation current setting, the investigators designed this study.

Official Title
-----------------
Priming Dose of Rocuronium and Milliamperage Value for Supramaximal Stimulation of NeuroMuscular Transmission Monitor

Conditions
-----------------
Neuromuscular Blockade

Intervention / Treatment
-----------------
* Procedure: Rocuronium priming dose


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients receiving general anesthesia and use rocuronium for induction Exclusion Criteria: Muscular disease Peripheral neuropathy Difficult airway or difficult mask ventilation Allergy to study related medication Pregnant woman < 20-year-old or > 65-year-old BMI <18.5 or BMI>24.9

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Rocuronium priming dose 0.06mg/kg<br>Add the priming dose of rocuronium 0.06mg/kg after the first supramaximal stimulation data measured | Procedure: Rocuronium priming dose<br>* Add the priming dose of rocuronium after the first supramaximal stimulation data measured<br>|
| Active Comparator: Rocuronium priming dose 0.12mg/kg<br>Add the priming dose of rocuronium 0.12mg/kg after the first supramaximal stimulation data measured | Procedure: Rocuronium priming dose<br>* Add the priming dose of rocuronium after the first supramaximal stimulation data measured<br>|
| Active Comparator: Rocuronium priming dose 0.18mg/kg<br>Add the priming dose of rocuronium 0.18mg/kg after the first supramaximal stimulation data measured | Procedure: Rocuronium priming dose<br>* Add the priming dose of rocuronium after the first supramaximal stimulation data measured<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Supramaximal stimulation value | whether the supramaximal stimulation changs after 2 minutes of priming dose of muscle relaxant use | since general anesthesia induction to endotracheal tube intubation, about 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| supramaximal stimulation value change by time | whether the supramaximal stimulation changs have a trend | since general anesthesia induction to endotracheal tube intubation, about 10 minutes | 
| dose of rocuronium | whether the change of supramaximal stimulation change is muscle relaxant dose responsive | since general anesthesia induction to endotracheal tube intubation, about 10 minutes | 
| Time to intubation | how long does it take from the full dose of muslce relaxant given to TOF count <2 | since general anesthesia induction to endotracheal tube intubation, about 10 minutes | 
| Intubation condition | the intubation condition with priming method used. Evaluate with scoring scale. scale range from 0-3. 0 presented as poor Jaw relaxation, closed vocal cord, and severe cough or bucking when intubation; to 3 represent a condition with good jaw relaxation, open vocal cord, and no repsponse to stimulation. | since general anesthesia induction to endotracheal tube intubation, about 10 minutes |