AIMS AND OBJECTIVESSaddle block anaesthesia is most commonly used technique for perineal surgeries, i.e. haemorrhoids, fissure-in-ano, etc., as it is most economical and easy to administer. Spinal anaesthesia by bupivacaine may be too short for providing postoperative analgesia. Hence, various adjuvants have been used with Local anaesthetics to provide good intraoperative anaesthesia and to prolong postoperative analgesia. The aim of our study was to evaluate the effects of intrathecal administration of dexmedetomidine 10 µg on low dose bupivacaine 0.5% (5 mg), to know the onset and duration of sensory and motor blockade, the haemodynamic effects, duration of analgesia and the occurrence of side effects. METHODOLOGYThis prospective randomized double blind study included 60 patients. Patients were randomly allocated into two groups of 30 patients each. Group D received 5 mg of 0.5% hyperbaric with dexmedetomidine 10 µg (0.5 mL) and Group N received 5 mg of 0.5% hyperbaric bupivacaine with 0.5 mL of normal saline. The onset of sensory and motor block, haemodynamic effects, duration of analgesia and occurrence of side effects were noted. RESULTSThe mean time taken for the onset of sensory block was 6.36±1.2 min and 8.23±1.7 significantly rapid with D Group compared to group N. The total duration of analgesia (360±15 min and 210±30 min in Group D and Group N respectively, P <0.000) and time to first rescue analgesic (370.85±15 min, 230.8±15 min in Group D and Group N respectively, P <0.001) were increased significantly by addition of dexmedetomidine without significant motor block and with minimal side effects. CONCLUSIONDexmedetomidine added intrathecally for saddle block had favourable effects on onset of sensory and total duration of analgesia and rescue analgesia.

BACKGROUNDVarious adjuvants are being used with local anaesthetics intrathecally for prolongation of intraoperative and postoperative analgesia. Dexmedetomidine, the highly selective alpha-2 adrenergic agonist is a new neuraxial adjuvant gaining popularity. Fentanyl is commonly used as an opioid adjuvant to local anaesthetic for spinal anaesthesia.