Intubating Condition After Magnesium Pre-treatment

Study Overview
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Brief Summary
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Magnesium had an inhibitory effect on neuromuscular transmission and caused a decrease in muscle fiber membrane excitability. It reduces the amount of acetylcholine that is released at the motor nerve terminal by decreasing the calcium conductance of presynaptic voltage-dependent calcium channels. After pre-treatment with magnesium, an increased speed of onset and a prolongation of the recovery period of neuromuscular blockade have been observed with other non-depolarizing neuromuscular blocking agent (NMBA) such as atracurium, vecuronium and rocuronium. Rocuronium is the currently preferred NMBA used as an alternative to succinylcholine for rapid tracheal intubation. As an alternative to succinylcholine, high doses of NMBA have been tested for rapid sequence intubation. This excessively high dose of rocuronium, however, prolongs the duration of the neuromuscular block and this may not be warranted in every surgical setting. The reduction of onset time of rocuronium by magnesium pre-treatment can make intubation condition more rapid and much better clinically. It will thus be interesting to compare intubation conditions of a standard intubation dose of rocuronium after magnesium pre-treatment with high dose of rocuronium or standard dose of rocuronium.

Official Title
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The Influence of Magnesium Sulphate Pretreatment on Intubating Conditions During Rapid Sequence Induction

Conditions
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Easy of Laryngoscopy Manipulation, Vocal Cord Position or Movement, Patient Reaction to Intubation and Cuff Inflation, Mean Arterial Pressure, Heart Rate

Intervention / Treatment
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* Drug: magnesium sulphate
* Drug: normal saline
* Drug: normal saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients undergoing operation under general anesthesia American Society of Anesthesiologist physical status I or II 20-65 year old male or female Exclusion Criteria: hepatic or renal dysfunction respiratory or cardiovascular dysfunction neurologic disorder neuromuscular disease pregnancy body mass index (BMI) >30 kg/m2 or <16.5 kg/m2 anticipated difficult airway higher magnesium level than normal range in preoperative evaluation chronic medication with calcium channel blocker or magnesium history of known allergy to magnesium sulphate or any other study drugs

Ages Eligible for Study
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Minimum Age: 20 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

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: group M<br> | Drug: magnesium sulphate<br>* The patients of group M receive 50 mg/kg of magnesium sulphate in 100 ml of isotonic saline over 10 min immediately before anaesthesia induction. After induction of anesthesia with alfentanil (10 μg/kg) and propofol (2 mg/kg), rocuronium 0.6 mg/kg is given over 5 s in a running infusion.<br>|
| Placebo Comparator: Group R-0.6<br> | Drug: normal saline<br>* Patients in the group R-0.6 receive the same volume of isotonic saline over the same period, and rocuronium 0.6 mg/kg is given after the induction of anesthesia with alfentanil (10 μg/kg) and propofol (2 mg/kg).<br>|
| Placebo Comparator: Group R-0.9<br> | Drug: normal saline<br>* Patients in the group R-0.6 receive the same volume of isotonic saline over the same period, and rocuronium 0.9 mg/kg is given after the induction of anesthesia with alfentanil (10 μg/kg) and propofol (2 mg/kg).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the intubating conditions | The anesthesiologist also assessed the intubating conditions as per the intubation scoring system of the Good Clinical Research Practice guideline. | 1 minute during intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| mean arterial pressure (MAP) | They were recorded pre-induction (base line), just before intubation, and every minute thereafter for 5 min. | 5 min before intubation, immediate before intubation, post-intubation 1, 2, 3, 4, and 5 min. | 
| heart rate (HR) | They were recorded pre-induction (base line), just before intubation, and every minute thereafter for 5 min. | 5 min before intubation, immediate before intubation, post-intubation 1, 2, 3, 4, and 5 min. |