Comparison Between Magnesium Sulphate and Dexmedetomidine as an Adjuvant to Bupivacaine in Ultrasound Guided Transverse Abdominis Plane Block as Post-Operative Analgesia for Parturients Undergoing Caesarean Section

Abstract

Background:

Cesarean section (C-section) is a major surgical procedure and effective post-operative pain management is crucial for optimal recovery and maternal well-being. The Transversus Abdominis Plane (TAP) block, an established regional analgesia technique, offers effective pain relief by blocking the sensory nerves of the anterior and lateral abdominal wall. Among the adjuvants used to enhance the efficacy and duration of TAP blocks, Magnesium Sulfate (MgSO₄) and Dexmedetomidine have shown promise. However, there is limited research comparing their analgesic efficacy specifically in C-section patients.

Aim:

This study aims to compare the post-operative analgesic effects of Magnesium Sulfate and Dexmedetomidine when added to Bupivacaine in Transversus Abdominis Plane (TAP) blocks for patients undergoing cesarean section under ultrasound guidance.

Materials and Methods:

This was a prospective, double-blinded, randomized controlled trial conducted on 50 patients undergoing elective cesarean sections. The patients were randomly divided into two groups: Group M received Bupivacaine 0.25% with Magnesium Sulfate (500 mg), and Group D received Bupivacaine 0.25% with Dexmedetomidine (0.5 mcg/kg). The primary outcome was the duration of post-operative analgesia, and secondary outcomes included the total requirement of rescue analgesia, Visual Analog Scale (VAS) scores for pain, and hemodynamic status over a 24-hour post-operative period.

Results:

The study found that Dexmedetomidine significantly prolonged the duration of analgesia (23.72 ± 0.879 hours) compared to Magnesium Sulfate (7.45 ± 1.03 hours) with a p-value of 0.001. Total rescue analgesia requirement was lower in the Dexmedetomidine group (51.35 ± 0.466 mg) compared to the Magnesium Sulfate group (52.13 ± 0.68 mg), with a p-value of 0.045. VAS scores were significantly lower in the Dexmedetomidine group at 8, 12, and 24 hours post-operation. Hemodynamic stability was better maintained in the Dexmedetomidine group, with a significantly higher Mean Arterial Pressure (MAP).

Conclusion:

Dexmedetomidine was more effective than Magnesium Sulfate in providing prolonged analgesia, reducing opioid consumption, and improving hemodynamic stability. These findings suggest that Dexmedetomidine may be a superior adjuvant for post-Cesarean analgesia in TAP blocks.