Evaluation of Single Epidural Bolus Dose of Magnesium Sulphate as an Adjuvant to Fentanyl for Postoperative Analgesia in Orthopaedic Hip Surgeries

Abstract

BACKGROUND AND OBJECTIVES: Magnesium has been used as an adjuvant by various routes, including intravenous, intrathecal and epidural in different dosage regimens. This is a prospective, randomized, controlled study designed to assess the efficacy of single bolus administration of Magnesium epidurally as an adjuvant to epidural fentanyl for postoperative analgesia in patients undergoing orthopedic hip surgeries under combined spinal epidural anesthesia. MATERIALS and METHODS: 50 Patients of ASA grade I and II aged 35 to 50 years of either gender undergoing orthopedic hip surgeries enrolled in study received combined spinal epidural anesthesia with 3 ml of 0.5% hyperbaric bupivacaine intrathecally. After surgery patients were randomized into Group F (epidural fentanyl 50µg in 10ml saline) and Group FM (epidural magnesium 75 mg along with fentanyl 50µg in 10 ml saline). Rescue analgesic is provided by intravenous tramadol if VAS score >4. Patient's first analgesic requirement time and duration of analgesia were recorded. RESULT: The duration of analgesia was significantly longer for Group FM compared to Group F. The frequency of rescue analgesics required in 24 hr postoperative period in Group FM was significantly less than that in Group F. CONCLUSION: The administration of magnesium as an adjuvant to epidural fentanyl for postoperative analgesia results in significantly lower VAS with prolonged duration of analgesia as compared to epidural fentanyl alone.