The Effect of Adding Magnesium Sulphate to Epidural Bupivacaine Compared to the Addition of Fentanyl to Epidural Bupivacaine in Patients Undergoing Lower Limb and Pelvic Orthopedic Surgery under Combined Spinal Epidural Anesthesia

Abstract

Epidural anesthesia is safe and inexpensive technique with the advantage of providing surgical anesthesia and prolonged postoperative pain relief. Research continues concerning different techniques and drugs that could provide better surgical anesthesia and postoperative pain relief. The use of adjuvants with epidural local anesthetics improves the duration and quality of analgesia and decreases the potential risk of toxicity by decreasing the dose of local anesthetic. Combined spinal epidural anesthesia reduces the potential for problems, such as missed segments, incomplete motor block, poor sacral spread and local anesthetic toxicity that can occur with epidural anesthesia. Magnesium is the fourth most plentiful cation in the bodyand the second most plentiful intracellular cation after potassium. As magnesium blocks the N-methyl-D-aspartate receptor, it can prevent central sensitization caused by peripheral nociceptive stimulation. Opioid analgesics when used as adjuvants, accelerate the onset, improve the quality and prolong the duratio if anesthesia and analgesia. Fentanyl, an opioid analgesic, is highly lipid- soluble with rapid onset and short duration of action.