Dexmedetomidine as adjuvant to Ropivacaine in subarachnoid block for postoperative analgesia in lower limb surgeries.

Abstract

Background and aim: Many adjuvants have been used with local anesthetics in spinal anesthesia but none has been found ideal. We have conducted this prospective randomized double blind study to evaluate the effect of intrathecal dexmedetomidine when added to
ropivacaine in spinal anesthesia. Methods: 50 patients who underwent lower limb surgeries under spinal anesthesia were included in this study and were randomly allocated in to two groups. Group C received intrathecal 3 ml of 0.75% ropivacaine + 0.5 ml normal saline and group D received intrathecal 3 ml of 0.75% ropivacaine + 5 μg dexmedetomidine in 0.5 ml of normal saline . Following intrathecal administration, onset of sensory and motor blockade, maximum dermatomal level achieved, duration of analgesia, hemodynamic parameters and incidence of side effects were observed. Results: Onset of sensory and motor block was earlier in group D compared to group C which was statistically significant. Block regression was significantly delayed with the addition of intrathecal dexmedetomidine (Group D) as compared to ropivacaine alone (Group C). Both, time to two segment regressions and time to
regression to S2 were delayed significantly in group D. The duration of analgesia was also significantly prolonged in group D (348.00±23.02 min) as compared to group C.(207.60±17.23min) There were no significant difference in haemodynamic parameters and
incidence of side effects in both the groups.Conclusion: The addition of dexmedetomidine(5 μg) to ropivacaine in spinal anesthesia produces significantly longer sensory and motor blockade along with prolonged postoperative analgesia, without any significant side effects.