Clonidine as a Sole Epidural Adjuvant in Combined Spinal-epidural: Clinical Study

BACKGROUND AND AIMS: Clonidine has been used as an epidural adjuvant along with local anesthetics; however, its use as a sole epidural adjuvant in combined spinal-epidural (CSE) anesthesia has not been explored; thus, this study aimed to assess the effects of clonidine as a sole epidural adjuvant in CSE on sensory and motor characteristics of 0.5% hyperbaric bupivacaine given by subarachnoid route. METHODOLOGY: A total of 60 patients belonging to the American Society of Anesthesiologists Classes I and II aged 18–60 years were randomized in two groups; group G300 and group GNS. G300 group received 300 mg clonidine and GNS received normal saline through epidural route followed by 15 mg of 0.5% hyperbaric bupivacaine as subarachnoid block. Onset of sensory block (time to T10) and motor block (time to Bromage 3), level of sedation (using Modified Ramsay Sedation Score), and hemodynamic changes were recorded. Two-segment regression, duration of analgesia (time for 1(st) rescue analgesia), and motor block (time to Bromage 0) were recorded. Student's t-test (two-tailed, independent) and Chi-square/Fisher's exact probability test were used for statistical analysis. RESULTS: The demographic data were comparable between the groups. The onset of sensory and motor block was significantly faster in G300 (sensory-71.63 ± 4.51 s, motor-55.63 ± 2.54 s) as compared to GNS (sensory-90.13 ± 4.88 s, motor-118.43 ± 9.50 s) (P < 0.001 and < 0.001, respectively). The two-segment regression was 199.33 ± 19.11 min and 79 ± 9.77 min in G300 and GNS, respectively, (P < 0.001). Duration of analgesia was 317.90 ± 15.32 min and 207 ± 20.66 min for G300 and GNS, respectively (P < 0.001), and duration of motor block was 409.9 ± 34.87 min and 204 ± 22.79 min for G300 and GNS, respectively (P < 0.001). The side effects such as hypotension and bradycardia were statistically and clinically not significant. CONCLUSION: Clonidine used as a sole epidural adjuvant in dose of 300 mg, for infraumbilical surgeries, has significantly faster onset of sensory and motor block with prolonged duration of analgesia and motor blockade and no significant side effects on a conventional subarachnoid block performed with 0.5% hyperbaric bupivacaine.