Background and aims: Effect of intrathecal dexmedetomidine as an adjuvant to isobaric ropivacaine in spinal anesthesia for abdominal hysterectomy is not much investigated. The objective was to assess the dose dependent effect of dexmedetomidine (3 mcg vs 5 mcg) as an adjunct to isobaric ropivacaine in spinal anesthesia.
Materials and methods: Forty selected female patients were randomized to receive intrathecal 0.5% isobaric ropivacaine (15 mg) with dexmedetomidine 3 mcg (Group D3) or 5 mcg (Group D5) in spinal anesthesia for abdominal hysterectomy. Block characteristics, hemodynamic changes, postoperative analgesia, and adverse effects were compared.
Results: Both groups were comparable regarding sensory-motor block characteristics and postoperative analgesia (P > 0.05). Four (10%) patients of Group D5 and 5 (12.5%) of Group D3 could not achieve desired T6 sensory level and Bromage score of 3(complete motor block) hence were converted to general anesthesia at the outset. Nine (22.5%) patients each in both groups required ketamine supplementation (0.5 mg/kg) for intraoperative pain at the time of uterine manipulation. Incidence of hypotension was comparable (55.56% in Group D5 and 37.14% in Group D3, P = 0.11), but this occurred significantly earlier in Group D5, P < 0.001. Sedation was also significantly more in Group D5 as compared with Group D3, P < 0.01.
Conclusion: We conclude that spinal anesthesia with isobaric ropivacaine (15 mg) with dexmedetomidine (3 mcg or 5 mcg) did not show much promise for abdominal hysterectomy as one third cases required analgesic supplementation. Both doses of dexmedetomidine produced a similar effect on block characteristic and postoperative analgesia; however, a dose of 5 mcg dose was associated with more hypotension and sedation.
Keywords: Abdominal hysterectomy; dexmedetomidine; isobaric ropivacaine.