Comparative study of subarachnoid injection of dexmedetomidine versus magnesium sulfate as adjuvants to bupivacaine in patients undergoing classical repair surgery

Abstract

Background Spinal anesthesia has several benefits over general anesthesia. Addition of adjuvants to local anesthetics improves the quality of the subarachnoid block. Objective We attempted to improve the quality of spinal anesthesia by the addition of magnesium sulfate or dexmedetomidine to intrathecal bupivacaine in patients undergoing classical repair surgery as regards primary outcome (quality of spinal anesthesia) and secondary outcomes (effect on hemodynamics and incidence of complications). Patients and methods This prospective randomized double-blinded controlled clinical study was carried out on 75 adult female patients scheduled for classical repair surgeries under spinal anesthesia who were assigned into three equal groups. Group D: 15 mg of 0.5% hyperbaric bupivacaine plus 10 μg dexmedetomidine was given to the patients. Group M: patients received 15 mg of 0.5% hyperbaric bupivacaine plus 0.5 ml magnesium sulfate (50 mg). Group C: patients received 15 mg of 0.5% hyperbaric bupivacaine plus 0.5 ml normal saline as control. The comparison was made among the three groups in regards to onset time of sensory and motor block, degree of postoperative pain relief, effect on hemodynamic stability, and total postoperative morphine consumption, and complications were recorded. Results There was a statistical difference among the three groups as regards the onset time of both sensory and motor block, which was faster in group D than in group C, and both were faster than group M. The duration of postoperative analgesia was significantly prolonged in D and M groups compared with the control group. The requirements of morphine sulfate in the first 24 h were significantly lower in the D and M groups compared with the control group. Conclusion Subarachnoid dexmedetomidine supplementation of spinal block was found to be a better option than intrathecal magnesium sulfate in patients undergoing classical repair surgeries, as it provides rapid onset of sensory and motor block; also, it improves the quality of postoperative analgesia and reduces postoperative analgesic requirements.