A COMPARATIVE STUDY BETWEEN MAGNESIUM SULPHATE AND CLONIDINE AS ADJUVANTS TO EPIDURAL ANESTHESIA IN PATIENTS UNDERGOING ABDOMINAL HYSTERECTOMIES.

Background: Epidural anesthesia is a common and safe technique for surgical anesthesia and post-operative analgesia. Adding other drugs to the neuraxial block is a wide spread trend to improve quality of anesthesia and prolong the duration of analgesia without any added side effects. Magnesium Sulphate has an antinociceptive effect by blocking calcium influx and non-competitively antagonizing NMDA receptor channels. Clonidine induces dose dependent spinal cord antinociception, mainly through stimulation of α2 adrenoreceptors in dorsal horn cells of spinal cord. This study was done to establish the effects of adding magnesium sulphate or clonidine as adjuvants to epidural bupivacaine in women undergoing abdominal hysterectomies. Methods: A total of 60 patients (ages 40 to 65, ASA I or II) were enrolled in the study and divided into 3 groups:- group A (control group), group B (magnesium sulphate group) and group C (clonidine group). All patients received 19 ml of standard epidural bupivacaine 0.5% with 50 mg magnesium sulphate in group B, 150 μg clonidine in group C and same volume of 0.9% saline in group A. Vital data were recorded. Onset of sensory block, motor block, time to 2 segment regression were also recorded. Sedation was assessed by sedation score. Pain was assessed by Visual Analogue Score (VAS). Adverse effects if any were recorded as well. Onset of anesthesia was rapid in Magnesium group (group B). In Clonidine group (group c) there were prolongation of duration of anesthesia and a sedative effect with a lower VAS score, but incidence of shivering was higher. Conclusion: This study revealed that magnesium sulphate is a safe adjuvant to epidural block with rapid onset of anesthesia, while Clonidine prolongs the duration of anesthesia, and causes sedation with some degree of bradycardia and hypotension.