Magnesium Sulphate as an Adjuvant to Ropivacaine in Bilateral Transversus Abdominis Plane Block for Laparoscopic Cholecystectomy: A Randomised Double-blind Clinical Study

Abstract

Introduction: Magnesium sulphate has the potential to treat and prevent pain by acting as an antagonist at N-methyl-DAspartate (NMDA) receptors. Many researchers found that magnesium sulphate as adjuvant to local anaesthetics reduces analgesic requirements in the postoperative period. Aim: To evaluate magnesium sulphate as an adjuvant to ropivacaine in ultrasound guided bilateral Transversus Abdominis Plane (TAP) block with respect to postlaparoscopic cholecystectomy pain. Materials and Methods: The present randomised doubleblind clinical study was conducted in the Department of Anaesthesiology, SKIMS Medical College, Srinagar, Jammu and Kashmir, between January 2022 and June 2022. Total 80 patients of American Society of Anesthesiologists (ASA) grade I and II were divided into two groups. Group A (n=40) patients received ropivacaine with magnesium and group B (n=40) patients received ropivacaine only. Pain was measured using the Visual Analogue Scale (VAS). Total rescue analgesia consumption during 24 hours, time to first request of rescue analgesia, postoperative nausea vomiting, sedation score and patient satisfaction score were recorded. Mann-Whitney U test was used for VAS score and patient satisfaction score. Results: Mean age of patients was higher in group A (47.95±13.853 years) than group B (46.45±11.940 years). Group A had 12 males and 28 females while in group B, there were 11 males and 29 females in group B. Group A showed better analgesic profile in the form of lower mean VAS, which were statistically significant (p-value<0.05). However, time to first request of rescue analgesia (743.5±58.214 minutes in group A vs 668.50± 214.375 minutes in group B; p-value=0.162) and total dose of rescue analgesia consumption were comparable in both groups (p-value>0.05). Also the sedation score (2.325±0.2529 in group A vs 2.295±0.2562 in group B; p-value=0.600) and patient satisfaction score (PSS) between the two groups (81.05±8.638 in group A vs 80.53±7.517 in group B; p-value=0.665) were statistically not significant. Incidence of postoperative nausea and vomiting was comparable in both groups (p-value=0.924). Conclusion: Addition of magnesium sulphate to ropivacaine in ultrasound guided bilateral TAP block significantly reduced pain scores in patients undergoing laparoscopic cholecystectomy.