Effect of addition of intrathecal magnesium sulphate to 0.5% hyperbaric bupivacaine and 0.5% isobaric levobupivacaine on duration of analgesia in parturients undergoing elective caesarean section: A prospective randomised study.

Abstract

Background and Aims:Addition of magnesium sulfate to local anesthetics improves the quality of spinal anesthesia for caesarean section. The aim of this study was to compare the effects of intrathecal 0.5% hyperbaric bupivacaine with 75-mg magnesium sulfate (MgSO4) and 0.5% isobaric levobupivacaine with 75-mg MgSO4 on the duration of analgesia in parturients undergoing elective caesarean section.Material and Methods:This prospective randomized double-blind parallel-group study was conducted in 60 parturients undergoing elective caesarean section who were randomly allocated to Group I or Group II to receive either 2 ml of 0.5% levobupivacaine with 75-mg MgSO4 or 2 ml of 0.5% hyperbaric bupivacaine with 75-mg MgSO4 intrathecally. The duration of postoperative analgesia along with sensory and motor block characteristics and hemodynamics were studied.Results:The duration of analgesia did not show a significant difference in the two groups (P = 0.175). The sensory onset time was faster in Group I (3.5 ± 1.3 min) as compared to that in Group II (4.8 ± 2 min; P = 0.004). The onset of motor blockade was not different in the two groups (P = 0.265), but there was a significant delay (P = 0.002) in motor recovery in Group II (267 ± 130.6 min) as compared to Group I (225 ± 85.4 min). Hemodynamics were comparable in the two groups.Conclusion:Intrathecal levobupivacaine with MgSO4 produces a similar duration of postoperative analgesia as compared to hyperbaric bupivacaine with MgSO4. Early motor recovery allowing early ambulation postoperatively makes isobaric levobupivacaine with MgSO4 a good alternative for caesarean sections.