Eighty patients undergoing lumbar fixation were randomized to receive either conventional general anesthesia with intraoperative magnesium sulfate (n=40) or conventional general anesthesia only (n=40). The primary outcome was the occurrence of postoperative delirium and insomnia, assessed using the Memorial Delirium Assessment Scale (MDAS) and Insomnia Severity Index (ISI), respectively. Secondary outcomes included pain scores (Visual Analog Scale, VAS) and predictors of these outcomes. Assessments were performed preoperatively and postoperatively up to two weeks. Overall, the study revealed that magnesium sulfate significantly reduced postoperative insomnia and pain but did not show a significant effect on delirium after adjustment. These findings suggest magnesium sulfate can mitigate insomnia and pain, potentially improving postoperative recovery.