INTRAVENOUS DEXMEDETOMIDINE PROLONGS BUPIVACAINE SPINAL ANESTHESIA

BACKGROUND: Dexmedetomidine is a potent selective alpha 2 agonist, which may prolong bupivacaine spinal block providing good cooperative sedation and longer post-operative analgesia. AIMS: This study aims at evaluating the efficacy of Intravenous dexmedetomidine over intravenous midazolam during intrathecal 0.5% bupivacaine in hysterectomy patients. METHODS: In a randomized prospective double blinded study, 50 ASA I patients posted for hysterectomy were recruited and divided in two groups: Group D received dexmedetomidine infusion 0.5 mcg/kg/hr. 5 minutes after spinal block with 0.5% bupivacaine 3ml, and Group M received midazolam infusion 0.04 mg/kg/hr. after 5 minutes of spinal block with 0.5% bupivacaine 3 ml. The maximum upper level of sensory block, time for regression of sensory and motor blocks was recorded. Post-operative analgesic requirements and sedation were observed. RESULTS: T6 was the highest level of sensory block in 72 % patients in dexmedetomidine group while in midazolam group only 28 % patients attained T6 level (p<0.001). Time for two segment regression of sensory block was longer in dexmedetomidine group, than in midazolam group (p<0.001). The motor block duration was similar in both the groups. The highest VAS pain score was lower in dexmedetomidine group (p<0.001). The time for first rescue analgesia was longer in dexmedetomine group (p<0.001). CONCLUSION: Intravenous dexmedetomidine is the better adjuvant in patients under spinal anesthesia. In addition to a cooperative sedation, a higher and a longer sensory block, and a longer pain free post-operative period was obtained.