Effects of Intraoperative Magnesium Sulfate on Perioperative Pain Relief After Spine Surgery

Summary

The treatment of postoperative pain is increasingly based on a multimodal approach and although opioids remain the drug of choice, they are often used in combination with other analgesics (paracetamol, cyclooxygenase inhibitors or non-steroidal anti-inflammatory drugs) and co-analgesic agents (clonidine and anti- NMDA such as ketamine or MgSO4). The rationale for combined analgesia is to achieve additive or synergistic analgesic properties while decreasing the incidence of side effects by reducing the dose of each agent. Nociceptive stimuli are known to activate the release of the excitatory amino acid glutamate in the dorsal horn of the spinal cord. The resultant activation of NMDA receptors causes calcium entry into the cell and triggers central sensitisation. This mechanism is involved in the perception of pain and mainly accounts for its persistence during the postoperative period.

Although magnesium is not a primary analgesic in itself, it enhances the analgesic actions of more established analgesics as an adjuvant agent. Magnesium produces a voltage-dependent block of NMDA receptors and has been reported to have analgesic properties that might be related to this inhibiting property. Magnesium sulfate has been reported to be effective in perioperative pain treatment and in blunting somatic, autonomic and endocrine reflexes provoked by noxious stimuli.

When magnesium was used intraoperatively, many researchers reported that it reduced the requirement for anesthetics and/or muscle relaxants.

Intraoperative use of magnesium sulfate can also be associated with decreased incidences of nausea and vomiting after surgery, which could have been due to the lower consumption of anesthetics (i.e. volatile agents), rather than any antiemetic effect of magnesium sulfate. In addition, perioperative i.v. administration of magnesium sulfate has another advantageous effect, as it decreases the incidence of shivering by up to 70-90%. Previous studies investigating the analgesic efficacy of MgSO4 in general, gynaecological, ophthalmic and orthopaedic surgery have shown conflicting results, while reports regarding spine surgery are extremely limited.

Our study was designed to investigate the effects of MgSO4 on perioperative pain relief and postoperative quality of recovery after lumbar laminectomy surgery.

Conditions

• Analgesia
• Pain, Postoperative
• Spine Disease

Interventions

DRUG

Magnesium Sulfate

Intravenous magnesium sulfate 20 mg/kg in 100ml isotonic saline 0.9% over a 15-min period before induction of anesthesia and 20 mg/kg/h by continuous i.v. infusion until surgery completion.

DRUG

Isotonic saline 0.9%

Isotonic saline 0.9% 100ml over a 15-min period before induction of anesthesia and thereafter continuous i.v. infusion until surgery completion in dosage identical to magnesium sulfate group.

Sponsors & Collaborators

• Aristotle University Of Thessaloniki

  lead OTHER

Principal Investigators

• Georgia Tsaousi · Aristotle University Of Thessaloniki

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2020-01-28

Primary Completion

2020-05-03

Completion

2020-05-05

Countries

• Greece

Study Locations