Magnesium sulfate for postoperative pain in orthopedic surgery: A narrative review

Magnesium Sulfate (MgSO4) is a widely used adjuvant in anesthesia. Often administered with local anesthetics, it is known to reduce analgesic and opioid consumption while extending the duration of analgesia. MgSO4 applications extend to orthopedic surgeries, cardiovascular and urogenital procedures, offering extended postoperative pain relief. While commonly administered through various routes, there is a research gap concerning the comparative efficacy of intrathecal (IT) and intravenous (IV) MgSO4 administration. This narrative review aims to provide a comparison between IT and IV administration of MgSO4 particularly following orthopedic procedures, where pain management is paramount. A comprehensive literature search was conducted across several electronic databases, trial registries, and gray literature from inception to 2023. Inclusion criteria encompassed studies investigating the effects of perioperative IT administration of magnesium compared to perioperative IV administration of MgSO4 in patients undergoing surgery, with no language restrictions. Our search identified 4326 articles, of which 9 randomized controlled trials met our inclusion criteria. We summarized these selected articles. Four studies discussed IT magnesium sulfate (MgSO4) administration, 2 focused on IT administration in orthopedic surgeries, and 3 explored both IV and IT administration of MgSO4 in orthopedic surgery. IT MgSO4 shows promise in postoperative pain management, delaying block onset and extending duration. Personalized administration choice, considering patient factors and surgery type, is crucial. Further research is needed to refine strategies for better patient outcomes, particularly following orthopedic surgeries.