Context: Dexmetedomidine, an alpha 2 agonist as adjuvant to spinal anesthesia for prolongation of sensory, motor block, postoperative analgesia. Aims: We studied effectiveness of intravenous dexmedetomidine in prolonging duration of subarachnoid block when administered as bolus and bolus plus infusion dose. Methods and Material: 100 ASA 1 and 2 patients scheduled to undergo elective surgeries under SAB were randomly allocated into two groups. After SAB,Group B received 1 μg/kg of dexmedetomidine bolus over 10 min and group Ireceived 0.5 mcg/kg over 10 mins followed by 0.5 mcg/kg over next 60 mins.Time of onset, duration of sensor and motor blockage, hemodynamic stability and sedation score were observed in both group patients. Statistical analysis used: Results were evaluated by applying paired t test and P value using SPSS statistical software. Results: Time to onset of sensory blockade (T10) in group B was 4.3 ±1.02 mins and group I - 5.2±1.6 mins. Time of onset of motor blockade in group B and I was 4.6 ± 1.01 and 5.5 ± 1.4 mins respectively. Two segment regression time was prolonged in group I – 124 ± 11.51 mins as compared to group B 110± 12.2 mins. Time to achieve complete sensory recovery in group B was 211 ± 10.2 min and group I was 240 ± 9.24 min. Time to achieve complete motor recovery in group B and I was 196 ± 9.6 and 219 ± 6.2 min respectively. Conclusions: Both dosage regimens of dexmedetomidine can be used for prolongation of spinal anaesthesia with bupivacine. Time of onset of block is faster in bolus group however bolus plus infusion dosage provides more prolonged sensory and motor regression of block.

Key messages: Intravenous Dexmedetomidine can be Used as an Adjuvant for Prolongation of Spinal Anaesthesia in Bolus as Well as Bolus and Infusion Doses.