Magnesium Infusion for Pain Management in Critically Ill Trauma Patients

November 24, 2025 updated by: University of California, Davis

Magnesium is a naturally occurring mineral that is important for your body and brain. Magnesium sulfate (study drug) is a medication containing magnesium that is commonly used to improve low blood levels of magnesium. Magnesium sulfate has also proven to be successful in managing pain before and after surgery. However, this drug has primarily been used for pain control in patients undergoing surgery. Patients in the ICU with injuries also need good pain control. Using magnesium may assist in decreasing narcotic (pain reliever) requirements and provide another non-narcotic drug for pain control.

The purpose of this study is to test the effectiveness of continuous, intravenous (into or within a vein using a needle) administration of magnesium sulfate for pain control in trauma patients admitted to the adult Intensive Care Unit. This will be compared to intravenous normal saline (salt solution).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This is a single center, double blind, randomized controlled study to demonstrate the effectiveness of continuous, intravenous administration of magnesium sulfate as compared to placebo in decreasing pain in critically injured patients.

Study Hypothesis The primary hypothesis is that continuous infusion magnesium sulfate will significantly decrease opioid requirements and pain scores in critically ill patients.

Background Magnesium is one of the most abundant cations in the human body. The physiologically active form of magnesium, ionized magnesium, is involved in hundreds of enzyme reactions that are important for homeostasis, action potentials, and membrane stability, among others.[Seo, et al] Hypomagnesemia is one of the most common electrolyte disturbances in the hospitalized patient, especially in the critically ill population. Studies have established that low magnesium levels increase mortality and morbidity in the critically ill patient,[Upala, et al] and thus magnesium is often repleted with intermittent infusion. Outside of its role in enzyme reactions, magnesium was discovered to have analgesic effects approximately twenty years ago.[Albrecht, et al] It appears to potentiate morphine analgesia, attenuate morphine tolerance, and suppress neuropathic pain.[Albrecht, et al] At a mechanistic level, these effects are thought to be secondary to magnesium regulating calcium influx into cells and antagonizing NMDA receptors in the central nervous system.

Magnesium has long been utilized in prevention and management of preeclampsia and eclampsia. A typical dosing regimen in this setting involves a 4 g loading dose of magnesium sulfate, followed by a magnesium infusion of 1-2 g/hr. When compared to eclampsia regimens, studies investigating the role of magnesium sulfate in multimodal surgical pain management consistently use lower doses. Even with this dosing, multiple trials have shown reduced postoperative pain and analgesic requirements.[Albrecht, et al, Sousa, et al, Hwang, et al, Shariat, et al] In one example, Shariat Moharari and others used a regimen of 40 mg/kg magnesium bolus followed by 10 mg/kg/hr infusion in perioperative gastrointestinal surgery patients, without adverse effects.[Shariat, et al]

Normal reference range for serum magnesium has been defined as approximately 0.7-1 mmol/L (1.5-2 mEq/L or 1.7-2.4 mg/dL).[Williamson, et al] Tramer et al. reported that a 3 g bolus dose of magnesium sulfate followed with 0.5 g/hr infusion for 20 hours resulted in an increase from baseline serum magnesium of approximately 0.6 mmol/L. Despite the higher post-treatment serum magnesium levels in the treatment group, no difference in safety outcomes was noted in comparison to the control group receiving 0.9% sodium chloride.[Tramer,et al] Similarly, Ozcan et al. found that 30 mg/kg bolus dose of magnesium sulfate followed by infusion of 10 mg/Kg/hr for 48 hours resulted in an increased serum magnesium level from baseline by approximately 0.7 mmol/L. The noted increase in serum magnesium level in this study also did not translate into any difference in safety endpoints between the intervention group and control group receiving 0.9% sodium chloride.[Ozcan, et al] Initial signs of magnesium toxicity following administration of magnesium sulfate have been reported to occur at serum magnesium levels greater than 3.5-5 mmol/L.[Lu, et al, Jahnen-Dechent, et al]

Despite the successful use of magnesium in perioperative pain management, it has yet to be applied in patient populations outside of the operating room. Given the need for adequate pain control among critically ill patients with traumatic injuries, the use of magnesium for pain management may assist in decreasing opioid requirements and provide another non-opioid adjunct for pain control.

Methods:

All trauma patients admitted to an adult ICU are screened during the first 24 hours after admission. If they meet criteria for admission to the study, an informed consent will be obtained. Patients meeting eligibility will be randomized by the Investigational Drug Service in a computer-generated, blinded block, 1:1 ratio to treatment with either magnesium sulfate (diluted appropriately in normal saline per standard procedures) or placebo (normal saline)."

Opioid administration will be recorded per usual nursing protocol in the electronic medial record. Heart rate, mean arterial pressure (MAP), respiratory rate, and RASS will be recorded at least every two hours per unit protocol.

A study worksheet will be posted at bedside for consistent collection of pain scores and CAM. Pain will be assessed per unit protocol using the numeric rating scale, with zero representing no pain and ten representing the worst pain imaginable.

The EMR will be reviewed; opioid administration, pain scores, and vital signs will be transferred to a separate data sheet through REDCap (Research Electronic Data Capture) software.

The primary outcome measure will be the total opioid requirement during the 24 hours of magnesium infusion. We performed this power analysis based on a recent retrospective cohort study performed at our institution.[Hamrick, et al] We estimate that the 24 hour OME requirement will decrease from 70 mg in the control group to 50 mg in the treatment group, with a standard deviation of 50 mg in each group, leading to an effect size of 0.4. Using the statistical program G*Power 3.0.1 with an effect size of 0.4, alpha of 0.05, power of 0.8, and equal allocation ratios, a sample size of 78 patients per group would be required.

Data will be assessed for normality by assessing distribution skewness and kurtosis. Depending on these results, t-tests or Wilcoxon rank-sum tests for two groups will be used to assess the primary outcome of total opioid dose. Other data, including pain scores, that is collected repeatedly will be analyzed with two-way repeated measures analysis of variance, with subsequent pair-wise comparison for any significant findings. Statistical significance will be set at a P value of less than 0.05. We will use SAS to perform the statistical analysis.

Study Type

Interventional

Enrollment (Estimated)

156

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • California
      • Sacramento, California, United States, 95817
        • Recruiting
        • UC Davis Health
        • Principal Investigator:
          • Christine S Cocanour, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • All trauma patients admitted to an adult intensive care unit
  • Signed informed consent
  • Hospital or trauma multimodal pain management order set used for pain management
  • Ages 18-99

Exclusion Criteria:

  • Admission to the Pediatric Intensive Care Unit.
  • Head Abbreviated Injury Score (AIS) of greater than 1
  • Known heart failure with reduced ejection fraction (EF < 40%)
  • Renal failure (GFR < 60)
  • Cardiac arrhythmia (except for sinus tachycardia)
  • Greater than 5% TBSA burn injuries
  • Moderate to severe alcohol withdrawal protocol ordered for patient
  • Regular use of opioids in the week prior to injury
  • Receiving continuous infusion of opioids
  • Patients expected to require general anesthesia between 24 and 48 hours after admission (during study drug administration)
  • Patients unable to provide consent is unavailable
  • Patients unable to provide a pain score
  • Pregnancy
  • Prisoners

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Magnesium Group
The magnesium group arm will receive a 40 mg/kg IBW (maximum 4 g) bolus of intravenous magnesium sulfate, followed by a continuous infusion of 0.5 g/hr for a total of 24 hours.
Drug: Magnesium Sulfate in Parenteral Dosage Form
IV bolus followed by continuous infusion for 24 hours
Placebo Comparator: Control Group
The control arm will receive the same volume and rate of saline as if they were in the experimental group.
Drug: Normal saline placebo
IV bolus followed by continuous infusion for 24 hours

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
total opioid requirements during study drug infusion
Time Frame: 24 hours during study drug infusion
oral morphine equivalents, OME
24 hours during study drug infusion

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
pain scores
Time Frame: daily x 4 days
numeric pain rating scale as reported by patient
daily x 4 days
Total oral morphine equivalents
Time Frame: daily x 4 days
daily x 4 days
ICU length of stay
Time Frame: through the patient's hospitalization for this injury, an average of 10 days
through the patient's hospitalization for this injury, an average of 10 days
ICU-free days
Time Frame: 14 days
14 days minus the number of ICU days
14 days
Hospital length of stay
Time Frame: through the patient's hospitalization for this injury, an average of 10 days
through the patient's hospitalization for this injury, an average of 10 days
Development of bradycardia
Time Frame: 24 hours during study drug infusion
24 hours during study drug infusion
Development of other dysrhythmia
Time Frame: 24 hours during study drug infusion
24 hours during study drug infusion
Respiratory depression
Time Frame: 24 hours during study drug infusion
Episodes of respiratory depression as measured by a respiratory rate less than 8
24 hours during study drug infusion
Prevalence of Richmond Agitation-Sedation Scale of -3 to -5
Time Frame: 24 hours during study drug infusion
Episodes of a -3 to -5 Richmond Agitation-Sedation Scale score
24 hours during study drug infusion

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of California, Davis

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 7, 2019

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2026

Study Registration Dates

First Submitted

November 13, 2019

First Submitted That Met QC Criteria

November 14, 2019

First Posted (Actual)

November 18, 2019

Study Record Updates

Last Update Posted (Actual)

November 26, 2025

Last Update Submitted That Met QC Criteria

November 24, 2025

Last Verified

November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 1440730

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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