Comparison of adjuvant effects of intrathecal magnesium sulfate and dexmedetomidine with hyperbaric bupivacaine

Abstract

Background: Surgeries involving infraumblical regions are commonly done under spinal anaesthesia. No single adjuvant to bupivacaine found to prolong the duration of analgesia and to reduce its limitations. Objectives: To compare the block characteristics of intrathecal administration of dexmedetomidine and magnesium sulfate as an adjuvant with bupivacaine in infraumblical surgeries. Materials and Methods: This is a prospective randomized double-blinded study. Around 90 American Society of Anaesthesiologist physical status I and II patients, scheduled for infraumblical surgeries were enrolled in this study. Patients were randomly assigned into Group B (bupivacaine), Group D (bupivacaine plus dexmedetomidine) and Group M (bupivacaine plus magnesium sulfate). In the operating theatre, baseline values were recorded. Onset and duration of sensory and motor block, time of rescue analgesia were noted. Results: The onset of sensory block was rapid in Group D (2.63 ± 0.66 min) and slow in Group M (6.35 ± 0.87 min) when compared to Group B (2.93 ± 0.785 min) with a statistically significant difference. Motor duration (min) was prolonged in Group D (423.00 ± 12.360) and early in the Group M (165 ± 31.55) when compared to Group B (219.23 ± 14.875). Conclusion: For the surgery, which requires prompt onset and long duration of analgesia,dexmedetomidine can be used as an adjuvant. However, surgical procedures that permit delayed onset block and shorter duration of analgesia,magnesium sulfate can be preferred.