Opioid Sparing General Venous Anesthesia With Magnesium Sulfate

Magnesium Sulfate in Substitution to Remifentanil. Intra-operative Analgesia Assessed by the Surgical Stress Index. Randomized and Blind Clinical Trial

Magnesium sulfate has been shown to be useful in many situations in medicine, such as eclampsia prevention and treatment, pulmonary hypertension, arterial pressure, asthma, cardiac arrhythmias and pheochromocytoma. Recently there has been a growing a big interest in this drug as an useful adjuvant in anesthesia, with analgesic and anesthetic sparing effect, antihyperalgesic property and potentialization of the neuromuscular blocker agent effect. On the other hand there has been a growing concern related to opioid administration, such as hyperalgesia, delayed return of intestinal function and the (still controversial) possibility of facilitating effect on tumor growth and metastases in cancer patients.

This project is based on a previous randomized, double blind prospective trial (conducted by one of these authors and not yet published) comparing two groups of patients who received general intravenous total anesthesia with propofol in controlled target infusion.

The surgical stress index is obtained by the interaction between the interval between heart beats and the amplitude of the photoplethysmography wave, whose algorithm generates a number related to the hemodynamic result of the increase of the sympathetic tone, which has shown to be the most sensitive resource in detecting the imbalance between the stimulus nociceptive and anti-nociception.

Study Overview

• Status: Completed
• Conditions: Postoperative Pain; Opioid Use; Magnesium Sulfate
• Intervention / Treatment: Drug: Remifentanil group; Drug: Magnesium sulfate group

Detailed Description

Magnesium sulfate has been shown to be useful in many situations in medicine, such as eclampsia prevention and treatment, pulmonary hypertension, arterial pressure, asthma, cardiac arrhythmias and pheochromocytoma. Recently there has been a growing a big interest in this drug as an useful adjuvant in anesthesia, with analgesic and anesthetic sparing effect, antihyperalgesic property and potentialization of the neuromuscular blocker agent effect. On the other hand there has been a growing concern related to opioid administration, such as hyperalgesia, delayed return of intestinal function and the (still controversial) possibility of facilitating effect on tumor growth and metastases in cancer patients.

This project is based on a previous randomized, double blind prospective trial (conducted by one of these authors and not yet published) comparing two groups of patients who received general intravenous total anesthesia with propofol in controlled target infusion.

The surgical stress index is obtained by the interaction between the interval between heart beats and the amplitude of the photoplethysmography wave, whose algorithm generates a number related to the hemodynamic result of the increase of the sympathetic tone, which has shown to be the most sensitive resource in detecting the imbalance between the stimulus nociceptive and anti-nociception.

Objectives The main objective of this project is to evaluate the feasibility of the use of magnesium sulfate in replacement of remifentanil as the main analgesic agent in total venous general anesthesia in patients submitted to post-bariatric dermolipectomy surgery.

The secondary objectives will be comparison of propofol consumption, time to onset of action, time of action and cisatracurium consumption between groups. We will evaluate pain scores in the immediate postoperative period and in the mornings and afternoons of the 3 days after surgery.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Brazil
  • São Paulo, Brazil, 01246-903
    • Hospital das Clínicas - Faculdade de Medicina da Universidade de Sao Paulo

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 16 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• age 18 to 60 year-old
• body mass index < 35 kg/m²
• American Society of Anesthesiologists score < III
• agreement to participate and sign the informed consent form.

Exclusion Criteria:

• Allergy to any medications of the trial
• neuromuscular diagnosed disorder
• cardiac conduction blockade (atrioventricular block II or higher),
• use of illicit drugs
• use of calcium channel blockers
• creatinine > 2 mg/dl.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Remifentanil group; Intravenous anesthesia with propofol and remifentanil	Drug: Remifentanil group; Venous general anesthesia with propofol and remifentanil.
Experimental: Magnesium group; Intravenous anesthesia with propofol and magnesium sulfate	Drug: Magnesium sulfate group; Venous general anesthesia with propofol and magnesium sulfate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Feasibility of using magnesium sulfate as analgesic of venous general anesthesia	Changes in systolic blood pressure (mmHg) after tracheal intubation and surgical incision in both groups.	Surgery time

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Anesthetic consumption.	Consumption of propofol (mg) and cisatracurium.	During surgery
Neuromuscular blocker action	Onset and offset of cisatracurium (minutes)	During surgery
Postoperative pain	Pain scores (verbal numerical scale from 0 to 10).	Three days

Collaborators and Investigators

• Sponsor: University of Sao Paulo General Hospital
• Investigators: Principal Investigator: Joaquim Vieira, Professor, University of Sao Paulo School of Medicine

Study record dates

Study Major Dates

• Study Start (Actual): June 3, 2019
• Primary Completion (Actual): January 6, 2022
• Study Completion (Actual): January 6, 2022

Study Registration Dates

• First Submitted: June 25, 2019
• First Submitted That Met QC Criteria: July 1, 2019
• First Posted (Actual): July 2, 2019

Study Record Updates

• Last Update Posted (Actual): November 4, 2022
• Last Update Submitted That Met QC Criteria: November 3, 2022
• Last Verified: November 1, 2022

More Information

Terms related to this study

• Keywords: opioid; Postoperative pain; Postoperative analgesia
• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications; Pain; Neurologic Manifestations; Pain, Postoperative; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Anti-Arrhythmia Agents; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Anesthetics; Analgesics, Opioid; Narcotics; Membrane Transport Modulators; Anticonvulsants; Calcium-Regulating Hormones and Agents; Reproductive Control Agents; Calcium Channel Blockers; Tocolytic Agents; Remifentanil; Magnesium Sulfate
• Other Study ID Numbers: CAAE 12614719.1.0000.0068

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No
• IPD Plan Description: We have no plan to made individual participant data available to other researchers.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No