Opioid Sparing General Venous Anesthesia With Magnesium Sulfate

Not Applicable

Completed

• Conditions: Magnesium Sulfate; Postoperative Pain; Opioid Use
• Interventions: Drug: Magnesium sulfate group; Drug: Remifentanil group

• Registration Number: NCT04005599
• Lead Sponsor: University of Sao Paulo General Hospital

Brief Summary

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.

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 Timeline

• Study Start: 2019-06-03
• Study First Submitted: 2019-06-25
• Study First Submitted QC: 2019-07-01
• Study First Posted: 2019-07-02
• Primary Completion: 2022-01-06
• Study Completion: 2022-01-06
• Status Verified: 2022-11
• Last Update Submitted: 2022-11-03
• Last Update Posted: 2022-11-04

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 40

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Magnesium group	Magnesium sulfate group	Intravenous anesthesia with propofol and magnesium sulfate
Remifentanil group	Remifentanil group	Intravenous anesthesia with propofol and remifentanil

Primary Outcome Measures

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

Secondary Outcome Measures

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

Trial Locations

Locations (1)

Hospital das Clínicas - Faculdade de Medicina da Universidade de Sao Paulo; 🇧🇷 São Paulo, Brazil