ABSTRACT
Magnesium as an inorganic ion has several products containing it and has a number of therapeutic properties. A very common product, magnesium-sulfate has been proven in field of anesthesiology. This study looks at the effect of intra-articular injection of magnesium-sulfate on acute pain following knee surgery for diagnostic arthroscopy in patients undergoing general anesthesia. 60 patients were selected and divided randomly to 2 groups in this double-blind, randomized, placebo-controlled clinical trial. All anesthesia and surgery methods were the same in both groups. One group received intra-articular magnesium sulfate and the second group received the same volume of placebo. Postoperative pain scores were checked at the 1[st], 3[rd], 6[th], 12[th] and 24[th] hours after the operation by a Visual Analog Scale [VAS] pain assessment scoring system. To present the results Mean [ +/- SD] was used and the P-value less than 0.05 were considered statistically significant. There was no statistically significant difference between the 2 groups for basic variables. Pain reported by the first group who received intra-articular magnesium sulfate solution was significantly less at the 1st hour postoperatively, than the other group [8.7 +/- 1.05 vs 5.53 +/- 1.91, respectively]. Also, at the 6[th] and 12[th] hours postoperatively, the difference was significant [p<0.0001]; but it was not at the 2[nd] 18[th] and 24[th] hours, postoperatively, in comparison to the group who received placebo [p>0.3]. In patients undergoing general anesthesia for arthroscopic knee surgery, intra-articular magnesium sulfate solution significantly reduced pain in the first few hours after the surgery