RESUMO
Introduction: Adequate analgesia following cesarean section decreases morbidity and ambulation, improves patient outcome,and facilitates care of the newborn baby. Intrathecal (IT) magnesium an N-methyl-D-aspartate antagonist has been shown toprolong analgesia without significant side effect in the healthy parturient.Aim: The aim is to study the effects of two different doses of IT magnesium sulfate 50 mg and 100 mg as an adjuvant to 0.5%hyperbaric bupivacaine 9 mg in elective lower segment cesarean section.Materials and Methods: A total of 60 patients with the American Society of Anesthesiologists I and II between the agegroups of 18 and 35 undergoing elective cesarean section under spinal anesthesia were randomly divided into three groups.Group S: 0.2 ml containing normal saline was added, Group M1: 0.2 ml containing 50 mg magnesium sulfate was added, andGroup M2: 0.2 ml containing 100 mg sulfate was added.Results: Onset of sensory and motor blockade was delayed in the magnesium sulfate group. Duration of spinal anesthesiaand motor block duration are prolonged in magnesium sulfate group (189.40 min). Post-operative analgesia was significantlyprolonged in the magnesium sulfate group when compared to control group (403.65 vs. 222.45 min).Conclusion: There is a delay in the onset of sensory and motor blockade with the use of magnesium sulfate. However, thereis prolonged motor blockade and duration of analgesia overlaps well into the post-operative period. This is beneficial for thepatient for post-operative analgesia. APGAR score was not affected in the groups.