Comparative Evaluation of Two Different Doses of Dexmedetomidine as an Adjunct to Levobupivacaine in Subarachnoid Block for Lower Abdominal Surgeries

Abstract

Background: Spinal anaesthesia is the preferred mode of anaesthesia for lower abdominal and lower limb surgeries. Levobupivacaine is being increasing used for spinal anaesthesia nowadays. Dexmedetomidine which is a potent α₂ agonist is being used as an adjunct to various local anaesthetics.

Aim: In this study, we aimed to compare two different doses of dexmedetomidine when added to Levobupivacaine in terms of onset, duration of sensory and motor block and post operative analgesia.

Method: A prospective, randomized study was carried out which included 100 patients between 18-65 years, of ASA I and II who underwent lower abdominal surgeries. Group D1 received 3ml levobupivacaine 0.5% +2.5mcg dexmedetomidine (in 0.5ml normal saline) total volume 3.5 ml and Group II D₂ received  3ml levobupivacaine  0.5% + 5mcg dexmedetomidine (in 0.5 ml of normal saline) total volume 3.5 ml. Sensory and motor block onset time, block reaching time to T6 dermatome, highest dermatome level of sensory block, two dermatome regression time, time to achieve complete motor block, VAS score at 2, 4 and 6 hours post spinal.

Results: Sensory block onset time, block reaching time to T6 dermatome and time to achieve complete motor blockade was same in both groups. Whereas motor block onset time was earlier in group D2 (p=0.003), two dermatome regression time was longer in group D2(p<0.001), and VAS score at 4 and 6 hrs was better in group D2(p-values 0.013 and <0.001 respectively).

Conclusion: We conclude that 5 mcg dose of dexmedetomidine has early onset of motor block, longer two dermatome regression and better VAS scores at 4 and 6 hours.