Ultrasound-guided transversus abdominis plane block for total abdominal hysterectomy: comparison between magnesium sulfate and dexamethasone as adjuvants

Abstract

Background Patients undergoing total abdominal hysterectomy (TAH) experience severe pain postoperatively, requiring a multimodal approach to analgesia. The transversus abdominis plane (TAP) block seems to be an ideal approach. This block may be achieved using bupivacaine with adjuvants such as dexamethasone or magnesium sulfate, which were compared in this study. Patient and methods A total of 60 patients subjected to TAH were randomly allocated to receive TAP block using 18 ml 0.25% bupivacaine (45 mg) with 2 ml (200 mg) of magnesium sulfate on either side in group M (n=30), whereas patients in group D (n=30) received 18 ml 0.25% bupivacaine (45 mg) with 2 ml (8 mg) of dexamethasone on either side. The visual analog score was considered as the primary outcome, whereas the secondary outcomes were included time to first analgesic request, the total postoperative opioid consumption, nausea and vomiting score, and patient’s satisfaction. Results Visual analog scores showed significantly higher values at 8 and 12 h in group D. The time to first analgesic request was prolonged with lower opioid consumption and more patient satisfaction in group M. Regarding nausea and vomiting, both groups were comparable. Conclusion Magnesium sulfate as an adjuvant to bupivacaine in TAP block for TAH provided better analgesia compared with dexamethasone.