Abstract: 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 thespinal cord to produce analgesic effects. The aim is to check efficacy and safety of intrathecaldexmedetomidine added to ropivacaine.Ropivacaine is a first single enantiomer-specific compound, which has a reduced risk of cardiotoxicity, neurotoxicity, and rapid recovery of motor function. Postoperative pain relief is an important issue with ropivacaine. It has been used with many adjuvants for lower limb surgery, which has other side effects. So, our concern is of using a drug as an adjuvant with ropivacaine which provides better intraoperative haemodynamic condition as well as prolonged postoperative analgesia with minimal side effects. Intrathecal α2-receptor agonists are found to haveantinociceptive action for both somatic and visceral pain. The purpose of this study was to compare intrathecal isobaric ropivacaine with the combination of isobaric ropivacaine and dexmedetomidine. The primary outcomes studied were time to regression of spinal blockade below level S2 and duration of pain

Dr.MALATHI.C.N(PROFESSOR)relief, defined as the time from intrathecal administration of dexmedetomidine to first request for supplemental analgesia by patients. Postoperative cumulative analgesic consumption and maximum visual analogue scale (VAS) pain score have been evaluated as secondary outcome

OBJECTIVES: 1)To study the onset, duration and regression of sensory and motor blockade of intrathecaldexmedetomidine added to 0.75% isobaric ropivacaine in orthopedic lower limb surgeries
2)To assess the time taken to request for first postoperative analgesia with and without intrathecaldexmedetomidine in 0.75% isobaric ropivacaine in orthopedic lower limb surgeries.

METHODS: Sampling technique: With simple random sampling technique, 60 patients will be selected who fulfil the inclusion, exclusion criteria and divided them into two groups of 30 each.Group D ( Dexmedetomidine group ): Will receive intrathecaldexmedetomidine at dose of 5mcgin 0.5ml of normal saline with 3ml of 0.75% isobaric ropivacaine.Group R( Ropivacaine group): Will receive intrathecal 3ml of 0.75% isobaric ropivacaine with 0.5ml of normal saline.

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).

CONCLUSIONS: Orthopaedic sugeries are associated with increased incidence of pain in the post-operative period. This study is undertaken to prove the efficiency of addition of dexmedetomedine to spinal anaesthesia and thus prolonging the duration as well as providing good post-operative analgesia.