Dexmedetomidine as an intrathecal adjuvant for postoperative analgesia

BACKGROUND: Spinal anaesthesia is the most common approach which is used for lower limb surgery. Dexmedetomidine is the recent drug which acts on α2-adrenergic receptors in the dorsal horn of the spinal cord to produce analgesic effects. AIM: Efficacy and safety of intrathecal dexmedetomidine added to ropivacaine. SETTING AND DESIGN: Randomised double blind trial. METHODS: Sixty patients were randomly allocated to receive intrathecally either 3 ml of 0.75% isobaric ropivacaine + 0.5 ml normal saline (Group R) or 3 ml of 0.75% isobaric ropivacaine + 5 μg dexmedetomidine in 0.5 ml of normal saline (Group D). RESULTS: The mean time of sensory regression to S2 was 468.3±36.78 minutes in group D and 239.33±16.8 minutes in group R. Duration of analgesia (time to requirement of first rescue analgesic) was significantly prolonged in group D (478.4±20.9 minutes) as compared to group R (241.67±21.67 minutes). The maximum visual analogue scale score for pain was less in group D (4.4±1.4) as compared to group R (6.8±2.2). CONCLUSION: The addition of dexmedetomidine to ropivacaine intrathecally produces a prolongation in the duration of the motor and sensory block.