A comparative study of intravenous dexmedetomidine and clonidine as pre-emptive analgesia to intrathecal bupivacaine in subarachnoid block - A randomized double blind study

Abstract

: Several drugs and drug regimens are used as adjuncts to local anaesthetics for neuraxial blockade in order to enhance its efficacy. In recent times novel drugs, adrenergic agonists like dexmedetomidine and clonidine are extensively used. Very few studies have compared the equipotent doses of both the drugs when given as pre-emptive analgesia. This study compares the efficacy of pre-emptive intravenous dexmedetomidine and clonidine for prolongation of bupivacaine spinal anaesthesia.: This is a prospective double-blind comparative study conducted at a tertiary care center from January 2021 to May 2022. 90 participants satisfying inclusion criteria were chosen after obtaining ethical Committee approval and informed consent. Study participants were randomly divided into two groups. Group C (n=45) received clonidine 0.5mcg/kg IV and Group D (n=45) received 0.5mcg/kg IV over 10mins following which subarachnoid block was given with hyperbaric bupivacaine 0.5% 15mg intrathecally. The following parameters were measured as onset, duration of sensory and motor blockade, duration of analgesia and number of rescue analgesics given in the postoperative period. Onset of sensory blockade (2.40+ 0.81) and motor blockade (2.78+ 0.88) was significantly faster in group D when compared to group C. Sensory blockade duration in group C and D was (100.22+ 11.38) and (129.33+ 13.55) respectively and was statistically significant. Similarly, Motor blockade duration was prolonged in group D (156.67+ 12.25) than in group C (121.78+ 14.35). Mean duration of analgesia in group D (169.51+19.23) and group C (143.8+18.78) illustrated statistically significant difference.: Dexmedetomidine when given as a pre-emptive analgesia enhances the effectiveness of bupivacaine by prolonging its duration of action when compared to clonidine at given doses.