Comparison of Morphine and Dexmedetomidine as Adjuvants to Isobaric Levobupivacaine for Spinal Anesthesia in Patients Undergoing Abdominal Hysterectomy.

Introduction: Various adjuvants to local anesthetics are used in spinal anesthesia for improving the quality and prolonging postoperative analgesia. We aim to compare the analgesic efficacy of morphine or dexmedetomidine given intrathecally as adjuvants to isobaric levobupivacaine.

Materials And Methods: Seventy patients of age group 18-60 years, American Society of Anesthesiologists 1 and 2 undergoing elective abdominal hysterectomy, were randomized into two groups. Group M received spinal anesthesia with 3 mL of 0.5% isobaric levobupivacaine with 250 μg of preservative-free morphine. Group D received 3 mL of 0.5% isobaric levobupivacaine with 5 μg of dexmedetomidine. Quality of anesthesia, sensory and motor block characteristics, duration of effective analgesia, and incidence of side effects were compared.

Results: The time for the first analgesic request was 320.80 ± 41.75 min in the dexmedetomidine group as compared to the morphine group (451.63 ± 38.55 min), = 0.000. The analgesic requirement in the first 24 h was significantly higher in Group D as compared to Group M, = 0.000. Adverse effects were similar in both the groups, except pruritus which was seen only in Group M.

Conclusion: Our study shows that the use of intrathecal morphine as an adjuvant to isobaric levobupivacaine provides better analgesia than intrathecal dexmedetomidine; however, adverse effects such as nausea and pruritus may be seen.