Background and Aim: Dexmedetomidine is a selective alpha adrenergic agonist with sedative, anxiolytic and sympatholytic properties without respiratory depression .They produce supraspinal analgesia by acting at the locus coeruleus and spinal analgesia by acting at substantia gelatinosa of spinal cord.

Aim of the study is to compare the efficacy of dexmedetomidine as an adjuvant to intrathecal 0.5% heavy bupivacaine and 0.5% heavy bupivacaine alone.

Methods: 40 patients undergoing knee arthroscopy were divided into two groups, group A received 15mg bupivacaine alone and group B received 15 mg bupivacaine combined with 5 microgram dexmedetomidine as spinal drug. Intrapoeratively haemodynamic parameters, time of onset of highest sensory level and duration of sensory blockade were recorded. Motor block was assessed by modified Bromage scale. Degree of motor blockade, time taken for attaining highest Bromage scale and score at the end of surgery were noted. Duration of effective analgesia was assessed by VAS scale.  Data analysis was done using chi square test for qualitative variables and t test or Anova for quntitative variables. The level of statistical significance was p value <0. 05.

Results: Addition of 5 microgram Dexmedetomidine to 15 mg intrathecal Bupivacaine significantly prolonged duration of analgesia with p value (p .000) significant at 0.05 level (p , 0.05) Duration of sensory blockade was longer with p <0 . 05 & duration of motor blockade was also prolonged with (. 000) significant at 0.05 level ( 0. 05 )

Conclusion: 5 microgram Dexmedetomidine is found to be an excellent adjuvant to intrathecal Bupivacaine for knee arthroscopy or lower limb surgeries in general. It provides good quality intra operative analgesia, minimal side effects and  excellent quality  post operative analgesia.

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Dr Harikrishnan.K.R

Assistant Professor, Dept. of Anaesthesiology, Govt. Medical College Kottayam