Evaluation of Dexmedetomidine as an Adjuvant to Intrathecal Bupivacaine in Infraumbilical Surgeries.

Abstract

Various adjuvants like morphine, buprenorphine and fentanyl, clonidine, ketamine are being used in anaesthetic practice since long for improvement of peri-operative analgesia following spinal anaesthesia. Such adjuvants have been helpful in induction of early ambulation but at the cost of their associated adverse effects. Therefore search for an effective adjuvant is still going on. Currently Dexmedetomidine, a highly selective α2-adrenoreceptor agonist is being studied for its adjuvant action in spinal anaesthesia. The present study aims to evaluate the efficacy of intrathecal Dexmedetomidine as an adjuvant to Bupivacaine in spinal anaesthesia in patients undergoing infra-umbilical surgeries. It was a prospective, double blind study among 60 patients undergoing infraumbilical surgeries under spinal anaesthesia. The patients were randomly allocated to 2 groups (Group I and Group II) of 30 each. Group I received hyperbaric bupivacaine (15 mg) alone and Group II received hyperbaric bupivacaine (15 mg) with Dexmedetomidine (5mcg). The onset time of sensory and motor block, regression time of sensory and motor block, duration of analgesia, haemodynamic parameters were recorded both intra and postoperatively. The primary efficacy parameters were to determine the onset and duration of sensory block, motor block and duration of postoperative analgesia. Secondarily any associated haemodynamic changes and adverse effects of Dexmedetomidine were also recorded. Continuous data were analysed using the Student's t-test and categorical variables by two-tailed Fisher-exact test or Chi-square test. Onset of sensory block was 129.33±14.8 seconds in Group II as compared to 208.33±19.18 seconds in Group I with total duration of sensory block as 317.70±16.16 minutes in Group II and 188±11.86 minutes in Group I. Similarly, onset of motor block was 226.33±31.86 minutes and 320.33±29.81 minutes, with total duration of motor block as 286.33±15.15 minutes and 166.5±12.11 minutes in Group II and in Group I respectively. Duration of analgesia was 333.6±20.67 minutes with Dexmedetomidine but 193.67±7.06 minutes in bupivacaine alone group. Dexmedetomidine as an adjuvant had shown early onset of sensory and motor block with longer duration of analgesia and haemodynamic stability in the present study as compared to bupivacaine alone.