COMPARISON OF EFFECT OF DEXMEDETOMIDINE VS. BUPRENORPHINE AS ADJUVANTS TO INTRATHECAL 0.5 % HYPERBARIC BUPIVACAINE IN LOWER LIMB ORTHOPAEDIC SURGERIES IN GOVERNMENT T.D. MEDICAL COLLEGE HOSPITAL ALAPPUZHA

Abstract

Background: Various adjuvants have been used with bupivacaine in spinal anaesthesia, the advantages being ability to use a lower dose of local anaesthetic, with better hemodynamic stability and prolongation of intraoperative and postoperative analgesia.

Objective: To compare effect of Dexmedetomidine vs. Buprenorphine as adjuvants to intrathecal 0.5 % hyperbaric bupivacaine in lower limb orthopedic surgeries based on duration of analgesia, onset of sensory & motor block, duration of sensory & motor block and side effects if any.

Methods: This study was done among patients in the age group of 18-60 years, belonging to ASA 1& 2, who underwent elective lower limb orthopaedic surgeries. Both the groups of patients were comparable with regard to age, height and weight. They were allocated into two groups of 28 patients each by using computer generated random sequence. Group A received 2.8ml of 0.5% hyperbaric bupivacaine and 0.2ml (5mcg) dexmedetomidine. Group B receive 2.8ml of 0.5% hyperbaric bupivacaine and 0.2ml(60mcg) buprenorphine

Result: The mean time of onset of analgesia in dexmedetomidine group was1.06 ± 0.13 min, which was significantly faster than Buprenorphine group 1.39 ± 0.13min (P<0.001). The mean duration of analgesia in dexmedetomidine group was 574.71 ± 25.08 min as compared to buprenorphine group which was 404.14 ± 13.28 min, the difference being statistically significant (p< 0.001). Mean onset of motor block in dexmedetomidine group was 1.27 ± 0.14 min and in buprenorphine group was 1.79± 0.14 min (p< 0.001). Mean duration of motor blockade in dexmedetomidine group was 387.96 ± 17.22 min and in buprenorphine group was 268.93 ± 13.21 min (p< 0.001). In dexmedetomidine group, time to two segment regression was 137.89 ± 18.61min which was significantly prolonged than buprenorphine group   111.96 ± 7.2min (p< 0.001).

Conclusion: Dexmedetomidine seems to be a better alternative to buprenorphine as adjuvant in spinal anaesthesia as it has faster onset of sensory and motor block,prolonged duration of analgesia and motor blockade along with fewer side effects.