BACKGROUNDSpinal Anaesthesia is the most common approach which is used for lower limb surgery. Ropivacaine is the preferred compound in comparison of Bupivacaine as firstly it is enantiomer specific which shows less cardio and neuro toxicity, and secondly it shows rapid recovery of motor functions and prolonged duration of sensory block. Dexmedetomidine, a neuraxial adjuvant, is highly selective α2 adrenoceptor agonist found in dorsal horn of spinal cord and in brain too to produce analgesic effect. We wanted to establish efficacy of Dexmedetomidine as a neuraxial adjuvant given intrathecally with 3 ml of 0.75% isobaric Ropivacaine to prolong anaesthesia and analgesia in spinal anaesthesia without additionally disturbing haemodynamic profile. METHODSIn our study, we took 60 patients fulfilling the inclusive and exclusive criteria scheduled for lower limb surgeries under spinal anaesthesia. They were randomly divided into two groups R and RD. R group received 3 ml of 0.75% isobaric Ropivacaine + 0.5 ml normal saline and RD group received 3 ml of 0.75% isobaric Ropivacaine with Dexmedetomidine 10 µg in (0.5 ml normal saline). Spinal anaesthesia was given with 25-gauge pencil point spinal needle in L3-L4 space under all aseptic conditions and drug was deposited after free flow of CSF was seen. RESULTSWe observed in our study that mean time taken by group RD to achieve desired block was less as compared to group R. The sensory and motor block was more prolonged and highly significant in group RD as compared to group R. Hemodynamic profile was same in both the groups. Duration of post-operative analgesia was more in group RD as compared to group R. Absolute analgesia duration being 350.33±59.49 in group RD as compared to 215.03±25.57 in group R (p<.001) the difference being statistically highly significant. The duration of effective analgesia in group RD was 490.83±38.73 minutes as compared to 271.83±34.43 minutes in group R (p<0.001). This difference was highly significant statistically. Sedation score was more in group RD as compared to group R. CONCLUSIONSThe effect of Ropivacaine in spinal anaesthesia can be potentiated by combining Dexmedetomidine, a neuraxial adjuvant, in a dose dependent manner. It does not produce any extra adverse effects. It could be an attractive alternative to General Anaesthesia in patients who require long duration surgery with cardiovascular and neurological co-morbidity. HOW TO CITE THIS ARTICLE:Saxena M, Dwibedy AM, Verma S, et al. Isobaric ropivacaine 0.75%, with and without intrathecal dexmedetomidine as an adjuvant, in lower limb surgery-a comparison.