Magnesium Sulfate Infusion on Postoperative Pain in Lumbar Surgery

The Effects of Perioperative Low-dose Magnesium Sulfate Infusion on Postoperative Pain in Lumbar Surgery

Effective postoperative analgesia after lumbar spine surgery (e.g., laminectomy, vertebroplasty, lumbar stabilization) is associated with faster recovery and shorter hospital stay. Multimodal analgesia aims to reduce opioid consumption and related adverse effects by combining agents with complementary mechanisms of action at peripheral and central levels.

Magnesium is one of the agents used in this approach. Its analgesic effects are attributed to inhibition of neuropathic pain, potentiation of opioid analgesia, and attenuation of opioid tolerance. Mechanistically, magnesium acts as a non-competitive NMDA receptor antagonist and modulates intracellular calcium influx, thereby reducing central glutamate release and limiting hyperalgesia.

However, the clinical efficacy of perioperative magnesium remains controversial. Outcomes may vary depending on timing (intraoperative vs. postoperative), dosing strategies (bolus vs. infusion), and total administered dose. The optimal dosage, administration method, safety profile, and dose-response relationship of magnesium for analgesic purposes are not yet clearly established.

This study aims to evaluate the effectiveness of perioperative low-dose magnesium sulfate (MgSO₄) in this context.

Study Overview

• Status: Completed
• Conditions: Postoperative Pain; Back Pain Lower Back Chronic
• Intervention / Treatment: Drug: Magnesium sulfate; Drug: normal saline

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye), 34371
    • Sisli etfal research and training hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• aged 18 years and older,
• ASA (American Society of Anesthesiologists) physical status I-II,
• awaiting to undergo lumbar spinal surgery under general anesthesia.

Exclusion Criteria:

• the presence of cardiac conduction disorders and/or cardiac comorbidities
• use of Ca channel blockers,
• hepatic/renal failure and allergy to Mg.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: the magnesium treatment group (Group M); Initial serum magnesium levels of the patients were measured at the beginning of the surgery; and subsequently an infusion of MgSO4 (10 mg/kg/h) in 100 mL of normal saline (NS) was initiated in groups M, respectively.	Drug: Magnesium sulfate; Initial serum magnesium levels of the patients were measured at the beginning of the surgery; and subsequently an infusion of MgSO4 (10 mg/kg/h) in 100 mL of normal saline (NS) was initiated in groups C, respectively.
Active Comparator: the control group (Group C); Initial serum magnesium levels of the patients were measured at the beginning of the surgery; and subsequently an infusion of and an infusion of 100 mL of NS (10 mg/kg/h) was initiated in groups C, respectively.	Drug: normal saline; Initial serum magnesium levels of the patients were measured at the beginning of the surgery; and subsequently an infusion of 100 mL of NS (10 mg/kg/h) was initiated in groups m, respectively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
visual analog scale	The Visual Analog Scale (VAS) is a unidimensional tool used to measure pain intensity. It typically consists of a 10-cm horizontal line ranging from "no pain" (0) to "worst imaginable pain" (10), on which patients mark the point that best represents their perceived pain level.	It will be measured at the 0th, 1st, 2nd, 3rd, 4th, and 5th hours.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Richmond Agitation-Sedation Scale.	The Richmond Agitation-Sedation Scale (RASS) is a validated clinical tool used to assess the level of agitation and sedation in hospitalized patients, particularly in intensive care settings. It ranges from +4 (combative) to -5 (unarousable), allowing clinicians to monitor and titrate sedative and analgesic therapy effectively.	It will be measured at the 0th, 1st, 2nd, 3rd, 4th, and 5th hours.
heart rate	heart rate will recorded in the peri-operative period.	It will be measured at the 0th, 1st, 2nd, 3rd, 4th, 5th, and 6th hours in the peri-operative period
sistolic blood pressure	sistolic blood pressure will recorded in the peri-operative period as mmhg.	It will be measured at the 0th, 1st, 2nd, 3rd, 4th, 5th, and 6th hours in the peri-operative period
diastolic blood pressure	diastolic blood pressure will recorded in the peri-operative period as mmhg.	It will be measured at the 0th, 1st, 2nd, 3rd, 4th, 5th, and 6th hours in the peri-operative period

Collaborators and Investigators

• Sponsor: Sisli Hamidiye Etfal Training and Research Hospital
• Investigators: Study Chair: sibel oba, şişli etfal eğitim araştırma hastanesi

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2021
• Primary Completion (Actual): November 1, 2021
• Study Completion (Actual): November 30, 2021

Study Registration Dates

• First Submitted: February 11, 2026
• First Submitted That Met QC Criteria: February 11, 2026
• First Posted (Actual): February 18, 2026

Study Record Updates

• Last Update Posted (Actual): February 18, 2026
• Last Update Submitted That Met QC Criteria: February 11, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Pain; Lumbar surgery; Magnesium sulfate; Visual analogue score
• Additional Relevant MeSH Terms: Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain; Pain, Postoperative; Sulfur Compounds; Pharmaceutical Preparations; Inorganic Chemicals; Crystalloid Solutions; Isotonic Solutions; Solutions; Sulfur Acids; Sulfates; Sulfuric Acids; Magnesium Compounds; Magnesium Sulfate; Saline Solution
• Other Study ID Numbers: salkaya-2

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No