BACKGROUND AND AIMS: 

     The aim and objective of the study is to compare three different doses of dexmedetomidine and to know the optimal dose of dexmedetomidine as adjuvant to bupivacaine in supra clavicular brachial plexus block for upper limb orthopaedic surgeries.

METHODS:

      We studied 60 ASA l & ll patients undergoing upper limb orthopaedic surgeries under supra clavicular brachial plexus block done by ultrasound technique. . Patients were randomly allocated to three groups. Group A :( n–20) – 30 ml 0.33% bupivacaine with dexmedetomidine 30µg.Group B :( n–20) – 30ml 0.33% bupivacaine  with dexmedetomidine 50µg.Group C: (n–20) – 30ml 0.33% bupivacaine  with dexmedetomidine 100µg. Patients were evaluated for sensory & motor block onset and duration, duration of analgesia, sedation score, and complications. Haemodynamic parameters including non–invasive blood pressure, pulse rate, oxygen saturation were noted intra operative and post operative period.

RESULTS:

      The sensory and motor block onset was delayed in group A (16.3±3.31/ 20.4±2.7 min) than group B (12.4±2.5/ 16.15±2.89 min) but shortest in group C (7.35±1/12.15±2.81 min).  The duration of both sensory and motor block was longest with group C (sensory 722.5±55.1min, motor 704±41.4 min) compared with group B (sensory 625.5±72.7 min, motor 604±98.6 min) and group A (sensory 432±69.8 min, motor 426.5±81.8 min). The mean duration of analgesia was dose dependent with highest in group C (736±67.1) than group B (642±76.5) and group A (480.5±81.3) in minutes.

CONCLUSIONS:

    We conclude that dexmedetomidine 100μg is an optimal dose to provide prolonged post–operative analgesia without much significant side effects.