A comparative study between intravenous and intraperitoneal magnesium sulphate for pain management in laparoscopic mini gastric bypass: a randomized clinical trial

Abstract

Abstract
 Background: Laparoscopic bariatric surgery has become a regular procedure, and it has largely replaced traditional open surgery. Patients experience postoperative pain even after laparoscopic surgery, although the intensity is low compared to open surgery. We compared the effectiveness of intravenous (IV) vs. intraperitoneal (IP) magnesium sulphate (MgSO4) injection in pain management in laparoscopic mini-gastric bypass surgery. 
 Methodology: We selected 100 patients based on convenient sampling and randomly divided into two groups; the IV group (50 patients) received MgSO4 50 mg/kg in 250 ml normal intravenously, and the IP group (50 patients) received MgSO4 50 mg/kg in 30 ml normal saline intraperitoneally. Nalbuphine was used as rescue analgesic and its total postoperative consumption during the first 24 h was recorded based on VAS score. Postoperative nausea and vomiting (PONV), sedation score and hemodynamic changes with pneumoperitoneum were also assessed.
 Results: Total nalbuphine consumption postoperatively was more in IV group than IP group (12 ± 3.03 mg vs. 8.3 ± 2.8 mg; P < 0.001). Postoperative pain score was significantly lower in IP group in comparison to IV group (P < 0.001). Intraoperative hypotension and bradycardia were significantly more (P = 0.03) in IV group (21% and 17% respectively) compared to IP group (10% and 7% respectively). Postoperative sedation and nausea and vomiting scores were reduced in IP group compared to IV group, the difference being highly significant (P < 0.001).
 Conclusion: Intraperitoneal MgSO4 instillation has better results than intravenous infusion in attenuation of postoperative pain and hemodynamic response associated with pneumoperitoneum, and results in less PONV when used in laparoscopic minigastric bypass patients.
 Key words: Analgesics / administration & dosage; Analgesics / pharmacology; Analgesics / therapeutic use; Bariatric; Magnesium Sulfate / administration & dosage; Magnesium Sulfate / pharmacokinetics; Magnesium Sulfate / therapeutic use; Mini-gastric bypass; Pain management; Pneumoperitoneum
 Citation: El-Sesy MG, Abdel Hameed AE, Abdelaziz AA, Ahmed IM, Elhennawy AM. A comparative study between intravenous and intraperitoneal magnesium sulphate for pain management in laparoscopic mini gastric bypass: a randomized clinical trial. Anaesth. pain intensive care 2022;26(4):450-457; DOI: 10.35975/apic.v26i4.1947
 Received: April 18, 2022; Reviewed: June 16, 2022; Accepted: July 10, 2022