Effect of Magnesium Sulfate on post-operative pain: A systematic review

Abstract

Post-operative pain is physiological reaction derived from tissue damage. One of the biggest concerns of patients is just about this pain. In practice usually the pain is controlled by opioid analgesics which could bring variety of side effects. Magnesium is an important Cation which plays a vital role in analgesic pathways both in human and animal models. MgSO4 is a vastly used drug in clinic. The analgesic effects of magnesium are based on acting as an antagonist of NMDA receptors in central nervous system. So we decided to systematically investigate the effects of perioperative intravenous magnesium sulfate on post-operative pain undergoing all surgeries. Method: This study is systematic review of randomized clinical trials which investigated the effects of MgSO4 on post-operative pain. After obtaining the code of ethics of study, two contributors will independently search the databases of Scopus, MEDLINE via PubMed, Embase, Ovid, Cochrane Library, Web of Science, with the proper combination of the MeSH Terms and free keywords, representing Magnesium Sulfate and post-operative pain based on PICO of the study. No limitation in time applied. All the included articles will be screened by title, abstract, and full-text by two independent contributors. The points of disagreement between the contributors will be addressed to the third contributor. The obtained articles were evaluated by JBI checklists and excluded in case of bias risk. After data extraction and collecting them in Excel, the probability of conducting a meta-analysis will be assessed and if possible, meta-analysis will be conducted using CMA software. The study protocol will be registered in PROSPERO. Results: After conducting a vast search among databases the total number of 2388 article found. After screening of received articles, 34 article met the inclusion criteria and included in this study. About 80 percent of included studies showed that perioperative intravenous administrated MgSO4 significantly decrease the total amount of analgesics used post-operatively. In the meantime severity of post-operative pain remains challenging. Almost half of the included studies did not report significant decrease in patients pain score. Out of 34 articles, 3 of them investigated the satisfaction of the patients in which 3 of them MgSO3 group have a meaningful increase in the satisfaction score. The time of first analgesic rescue was pursued in 7 studies which only in 4 of them, MgSO4 could prolong the time of first analgesic requested.