A Study of the Effects of Intravenous Magnesium Sulphate on Anaesthesia and Analgesia in Elective General Surgery Patients

Study Overview
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Brief Summary
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The aim of this double-blind randomized study will be to evaluate the effect an intravenous infusion of magnesium has on recovery outcomes after elective laparoscopic cholecystectomy

Detailed Description
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Magnesium consists one of the most important electrolytes of the human body, producing effects in various systems, one of them being the central nervous system. It has been shown that the administration of intravenous magnesium sulphate during anesthesia can significantly reduce the requirements for anaesthetic and analgesic agents, perioperatively, and improve the quality of post anesthetic recovery. The present study will examine the effect of administering intravenous magnesium sulphate during anesthesia in patients undergoing elective laparoscopic cholecystectomy surgery. This is a single centre, double-blinded, randomised controlled trial in an adult population, taking place in a tertiary medical centre in Athens. The study consists of three comparison groups of equivalent population, produced by double blinded randomisation. Each comparison arm will be administered a different regimen of magnesium sulphate/placebo. During the perioperative time, depth of anaesthesia will be monitored using the Bispectral Index, (BIS™) and the nociceptive level with nociception level index (NOL®). Dosing of the anaesthetic agent, desflurane, as well as of the analgesic medication, remifentanil, will be adjusted according to the prior indices. Patients included in the study will be monitored in the PACU and the surgical ward for the first 24 hours, postoperatively. Primary outcomes include the requirements for anaesthetic and analgesic agents, time to emergence, time to extubation, time to recovery, quality of recovery variables, pain scores during the first 24 hours and adverse effects and/or complications of magnesium administration. Ethical approval for this trial has been granted by the Ethics Committee of the hospital.

Official Title
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The Anesthetic and Analgesic Effects of Intravenous Magnesium Sulphate in Elective Laparoscopic Cholecystectomy

Conditions
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Pain, Acute, Pain, Postoperative, Pain, Nociceptive, Analgesia, Magnesium

Intervention / Treatment
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* Drug: magnesium bolus followed by normal saline infusion
* Drug: magnesium bolus followed by magnesium infusion
* Drug: normal saline bolus followed by normal saline infusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patents American Society of Anesthesiologists (ASA) class I-III elective laparoscopic cholecystectomy Exclusion Criteria: body mass index (BMI) >35 kg/m2 systematic use of analgesic agents preoperatively chronic pain syndromes preoperatively neurological or psychiatric disease on treatment pregnancy severe hepatic or renal disease drug or alcohol abuse language or communication barriers lack of informed consent

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: magnesium bolus<br>A bolus dose of magnesium of 40 mg/kg will be administered within 10 minutes preoperatively diluted in 100 mL of saline. Followingly, normal saline will be administered at a rate of 20 mL/h | Drug: magnesium bolus followed by normal saline infusion<br>* a bolus dose of magnesium will be followed by normal saline infusion<br>|
| Active Comparator: magnesium bolus and magnesium infusion<br>A bolus dose of magnesium of 40 mg/kg will be administered within 10 minutes preoperatively diluted in 100 mL of saline. Followingly, 10 mg/kg/h of magnesium will be administered intraoperatively diluted in a 60 mL syringe and administered at a rate of 20 mL/h | Drug: magnesium bolus followed by magnesium infusion<br>* a bolus dose of magnesium will be followed by a magnesium infusion<br>|
| Placebo Comparator: placebo<br>100 mL of normal saline will be administered within 10 minutes preoperatively. Followingly, normal saline will be administered at a rate of 20 mL/h | Drug: normal saline bolus followed by normal saline infusion<br>* a bolus of normal saline will be followed by normal saline infusion<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| pain score on arrival to Post-Anesthesia Care Unit (PACU) | pain score by the use of Numeric Rating Scale (NRS) on arrival to PACU, ranging from 0 to 10, where 0 means no pain and 10 means worst pain imaginable | immediately postoperatively | 
| pain score at discharge from Post-Anesthesia Care Unit (PACU) | pain score by the use of Numeric Rating Scale (NRS) at discharge from PACU, ranging from 0 to 10, where 0 means no pain and 10 means worst pain imaginable | at discharge from Post Anesthesia Care Unit (PACU), approximately 1 hour postoperatively | 
| pain score 24 hours postoperatively | pain score by the use of Numeric Rating Scale (NRS) 24 hours postoperatively, ranging from 0 to 10, where 0 means no pain and 10 means worst pain imaginable | 24 hours postoperatively |