Effect of intravenous dexmedetomidine on spinal anaesthesia with hyperbaric bupivacaine in lower limb orthopedic surgeries - A randomized controlled study

Introduction: Alpha-2 adrenoceptor agonists such as Clonidine, dexmedetomidine both have analgesic and sedative properties when used intravenous. Unsatisfactory regional anesthesia necessitates supplementary intravenous analgesia and deep sedation to relive anxiety AIM: To observe the effect of intravenous dexmedetomidine in spinal anaesthesia with respect to sensory block, motor block, depth of sedation and the time to first analgesic requirement in lower limb orthopedic surgeries. Materials and Method: 60 consenting patients undergoing lower limb orthopaedic surgeries were selected. Dexmedetomidine group (D) received a loading dose of 0.5 mcg/kg dexmedetomidine over 10 mins before spinal anaesthesia followed by an infusion of 0.5 mcg /kg/hr till the end of surgery. Control group ‘C’ received similar volume of normal saline infusion. The parameters observed were the highest sensory level achieved, time to two segment regression, duration of motor block and time to first requirement of analgesia. Ramsay score was used to assess sedation and hemodynamic parameters noted. Results: The maximum sensory level achieved was higher in group ‘D’ than in group ‘C’. The time to two segment regression, The duration of motor block and The time to first requirement of analgesia was prolong in dexmedetomidine then in control group. Also the sedation score were higher in group ‘D’. Conclusion: I.V. Dexmedetomidine as an adjuvant in spinal anaesthesia prolongs the duration of both sensory and motor blockade and also delays the time to rescue analgesia, thus eliminating the need to use multiple drugs for sedation and analgesia.