NCT07438366

Adding Magnesium Sulphate to Combined Pectointercostal Plane and Erector Spinae Plane Blocks for Acute and Chronic Post-Mastectomy Pain

Efficacy of Adding Magnesium Sulphate to Combined Pectointercostal Plane Block and Erector Spinae Plane Block for Acute and Chronic Post-Mastectomy Pain After Modified Radical Mastectomy. A Controlled Clinical Trial

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 60 (estimated)
• Sponsor: South Egypt Cancer Institute · Academic / Other
• Sex: Female
• Age: 18 Years – 65 Years
• Healthy volunteers: Not accepted

Summary

Given the burden of chronic postmastectomy pain and the need for effective, opioid-sparing analgesia, the propose of the randomized controlled trial is to evaluate the safety and efficacy of adding magnesium sulphate to the combination of PIP block and ESPB in patients undergoing modified radical mastectomy for reducing acute and chronic post mastectomy pain

Detailed description

Breast cancer remains one of the most common malignancies worldwide, and modified radical mastectomy (MRM) continues to be a mainstay surgical treatment in many cases. However, postoperative pain after MRM can be significant, both in the acute period and long-term, contributing to persistent pain syndromes, impaired recovery, and reduced quality of life. Regional anesthesia techniques such as the pectointercostal plane (PIPB) block and erector spinae plane block (ESPB) have gained wide acceptance as effective approaches to reduce perioperative analgesic requirements, improve pain control, and potentially mitigate chronic post-surgical pain. Magnesium sulphate (MgSO4 ) is increasingly studied as an adjuvant in regional anesthesia, owing to its NMDA-receptor antagonism, calcium channel modulation, and possible anti-inflammatory effects. Meta-analyses in peripheral nerve blocks, such as supraclavicular brachial plexus block, have demonstrated that adding MgSO4 prolongs sensory and motor blockade, delays the need for rescue analgesia, and is generally well tolerated. Moreover, in abdominal surgery, MgSO4 added to bupivacaine in a transversus abdominis plane (TAP) block significantly reduced postoperative pain scores and extended analgesia duration. Erector spinae plane block is particularly attractive in mastectomy because it provides extensive dorsal and lateral thoracic analgesia. Beyond ESPB and Pectointercostal Plane Block, other interfascial plane blocks in breast surgery have also shown benefit with magnesium. Such consistent results across different block techniques support the hypothesis that magnesium enhances regional anesthesia outcomes in breast surgery. Despite this promising data, there remain gap. No study has yet, concurrently evaluated magnesium as an adjuvant to both PIP block and ESPB in the same patient population, nor assessed its effects on both acute postoperative pain and the development of chronic postoperative pain. So, the aim of this randomized controlled trial is to evaluate the safety and efficacy of adding magnesium sulphate to the combination of PIP block and ESPB for reducing acute and chronic post mastectomy pain in patients undergoing modified radical mastectomy. A randomized controlled double-blinded study will be conducted in South Egypt Cancer Institute, Assiut University, after approval from the Institutional Ethics Committee. Primary outcome: Time to first rescue analgesia. Secondary outcomes: Total opioid consumption (morphine equivalent) in the first 24 hours postoperatively. Postoperative pain scores (VAS) at rest and movement. Incidence of postoperative nausea and vomiting. Block-related complications. Incidence and severity of chronic post mastectomy pain.

Conditions

• Post-mastectomy Pain Syndrome

Interventions

Type	Name	Description
PROCEDURE	Pectointercostal Plane Block (PIPB)	A high-frequency linear ultrasound probe will be placed at the level of the 2nd-3rd rib, medial to the pectoralis major muscle. The pectointercostal fascial plane located between the pectoralis major muscle and the external/internal intercostal muscles will be identified. Under in plane ultrasound guidance, the needle will be advanced into this plane, and the study drug will be administered. All patients will receive 20 mL of 0.25% bupivacaine; however, patients in Group M will additionally receive magnesium sulphate 150 mg diluted to 5 mL, which will be injected into the same plane.
PROCEDURE	Erector Spinae Plane Block (ESPB)	For this block, the patient will be positioned laterally. The ultrasound probe will be placed at the T3-T5 vertebral level to visualize the transverse process. An in- plane technique will be used to advance the needle into the deep fascial plane beneath the erector spinae muscle. Once the correct position is confirmed, 20 mL of 0.25% bupivacaine will be injected, with Group M patients receiving an additional 150 mg of magnesium sulphate diluted to 5 mL. The total magnesium dose administered in Group M will be 300 mg. Negative aspiration will be performed prior to each injection to avoid intravascular administration.
DRUG	Magnesium sulfate	All patients will receive 20 mL of 0.25% bupivacaine; however, patients in Group M will additionally receive magnesium sulphate 150 mg diluted to 5 mL, which will be injected into the same plane. The total magnesium dose administered in Group M will be 300 mg

Timeline

• Start date: 2026-02-15
• Primary completion: 2026-11-01
• Completion: 2027-02-15
• First posted: 2026-02-27
• Last updated: 2026-02-27