Magnesium for Shivering in Epidural Lidocaine Deliveries (Mag-SHIELD)

Intravenous Magnesium Sulfate for the Prevention of Intraoperative Shivering in Parturients Undergoing Cesarean Delivery Under Lidocaine Top-up Via a Pre-existing Epidural Catheter Inserted for Labor Analgesia - A Randomized Double-blind, Placebo-controlled Trial

Magnesium has been shown to decrease the shivering experienced from neuraxial anesthesia. This study aims to investigate whether magnesium decreases the shivering experienced in parturients undergoing labor epidural anesthesia for Cesarean delivery.

Study Overview

• Status: Suspended
• Conditions: Anesthesia
• Intervention / Treatment: Drug: Magnesium Sulfate; Other: Normal Saline

Detailed Description

Women who have epidurals in place and go on to require a Cesarean delivery typically have their epidurals 'topped-up' with a fast onset local anesthetic to ensure the lower body is fully numb for surgery. This is called an epidural 'top-up'. However, a side effect of epidural top-ups is shivering, which is uncomfortable for the mother and interferes with patient monitoring. Magnesium administration has been shown to decrease shivering in the non-pregnant population. Therefore, in this study the investigators aim to determine if magnesium given prior to an epidural top-up decreases the incidence and severity of shivering in the pregnant population.

• Study Type: Interventional
• Enrollment (Anticipated): 90
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • British Columbia
    • Vancouver, British Columbia, Canada, V6H 3N1
      • BC Women's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

1. Gestational age of ≥37 weeks
2. Women who are ≥ 19 years old
3. Women undergoing Cesarean delivery under lidocaine top-up via a preexisting epidural catheter inserted for labor analgesia
4. American Society of Anesthesiologist (ASA) Physical Status class 1 or 2

Exclusion Criteria:

1. Emergency Cesarean delivery with limited time for informed consent
2. Women who have received MgSO4 prior to study enrollment
3. Indication for alternative mode of anesthesia for Cesarean delivery (e.g., general anesthesia)
4. Medical conditions or medications that could lead to tremor or shivering. (e.g., movement disorder, untreated thyroid disease) or mask tremor or shivering (e.g., beta-blocker, benzodiazepine, anticonvulsants)
5. Active shivering at time of recruitment
6. Inability to read and understand English for the purpose of informed consent
7. Contraindications to receiving MgSO4 (hypersensitivity reactions, respiratory rate <16breaths/min, absent reflexes, urine output <100 mL during the previous 4 hours, renal failure, or hypocalcemia)
8. History of previous postpartum hemorrhage

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Magnesium sulfate; Magnesium sulfate (MgSO4) infusion will be commenced prior to epidural top-up.	Drug: Magnesium Sulfate; Bolus infusion: 100mL normal saline with 4g MgSO4 over 30 minutes Maintenance infusion: 25mL normal saline per hour with 1g MgSO4
Placebo Comparator: Normal saline; Normal saline infusion will be commenced prior to epidural top-up.	Other: Normal Saline; Bolus infusion: 100mL normal saline over 30 minutes Maintenance infusion: 25mL normal saline per hour

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of intraoperative shivering	Incidence measured as shivering present or absent	Through completion of cesarean surgical procedure (maximum 2 hours)
Severity of intraoperative shivering	Severity measured subjectively by anesthesiologist and patient	Through completion of cesarean surgical procedure (maximum 2 hours)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of hypothermia	Number of patients whose tympanic membrane temperature decreases below 36 degrees Celsius.	Through study completion (maximum 2.5 hours)
Incidence of hypotension	Number of patients who experience a greater than or equal to 20% reduction in systolic blood pressure.	Through study completion (maximum 2.5 hours)
Total vasopressor(s) dose		Through study completion (maximum 2.5 hours)
Total utertonic(s) dose		Through completion of cesarean surgical procedure (maximum 2 hours)

Collaborators and Investigators

• Sponsor: University of British Columbia
• Investigators: Study Chair: Anna West, BA MBBS, University of British Columbia; Study Chair: Vit Gunka, MD, University of British Columbia; Study Chair: Jonathan Collins, BA BM BCh MA, University of British Columbia; Study Chair: Monica Brunner, MD, University of British Columbia; Study Chair: Arianne Albert, PhD, Provincial Health Services Authority; Study Chair: James D Taylor, BSc, Provincial Health Services Authority

Study record dates

Study Major Dates

• Study Start (Actual): June 11, 2018
• Primary Completion (Anticipated): September 1, 2021
• Study Completion (Anticipated): September 1, 2021

Study Registration Dates

• First Submitted: February 7, 2018
• First Submitted That Met QC Criteria: February 13, 2018
• First Posted (Actual): February 20, 2018

Study Record Updates

• Last Update Posted (Actual): February 26, 2021
• Last Update Submitted That Met QC Criteria: February 23, 2021
• Last Verified: February 1, 2021

More Information

Terms related to this study

• Keywords: Magnesium; Shivering; Epidural top-up
• Additional Relevant MeSH Terms: 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; Membrane Transport Modulators; Anticonvulsants; Calcium-Regulating Hormones and Agents; Reproductive Control Agents; Calcium Channel Blockers; Tocolytic Agents; Magnesium Sulfate
• Other Study ID Numbers: H17-02408

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