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

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

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

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.

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