Publication:

A prospective randomised double-blind study of comparison of efficacy and safety of dexmedetomidine and clonidine as adjuvants to intrathecal isobaric ropivacaine 0.75% in lower limb surgeries

Background Studies comparing the efficacy of dexmedetomidine and clonidine as adjuvants to ropivacaine 0.75% in spinal anesthesia are few. The objective was to study the safety and efficacy of dexmedetomidine in comparison to clonidine as an adjuvant to ropivacaine in subarachnoid block.

Methods Patients were randomly allotted into 3 groups. Group R (n=30) patients received 3ml of 0.75% isobaric ropivacaine +0.5ml of 0.9% normal saline to a total volume of 3.5ml. Group RD (n=30) patients received 3ml of 0.75% isobaric ropivacaine +5μg of dexmedetomidine +0.9% normal saline to a total volume of 3.5ml. Group RC (n=30) patients received 3ml of 0.75% isobaric ropivacaine +30μg of clonidine +0.9% normal saline to a total volume of 3.5ml. The patients and the investigator were blinded for the study.

Results Time to reach T10 level of sensory block in group R was 7.6±1.3 min, group RC was 7.8±1.4 min and in group RD it was 7.9±1.4 min which was statistically not significant with p value 0.66. Time to reach motor onset to Bromage scale 4 was 9.8±1.4 min in group R, 10±1.4 min in group RC, 10.5±1.5 min in group RD which was statistically not significant with p value 0.24. Time to reach maximum sensory block in group R was 10.7±1.4 min, 10.6±1.1 min in group RC, 11±1.7 min in group RD which was statistically insignificant with p value 0.51.

Conclusions Intrathecal dexmedetomidine had superior anaesthetic effects with respect to duration of sensory blockade, motor blockade and duration of analgesia compared to intrathecal clonidine.