Oral Clonidine Premedication and its effect on Subarachoid block: A Randomised Study

ABSTRACT

Oral clonidine has been reported to prolong the sub arachnoid block and postoperative analgesia. The study was conducted to evaluate the effectiveness of oral clonidine as premedication on subarachnoid block. Methods: 100 patients of aged 20-60 years (ASA-1 and ASA-2 ) undergoing infraumbilical surgeries were included in this prospective, double blind randomized study. Patients divided in to two ( n = 50 ) groups. Group Ι patients receiving oral clonidine 150 μg one hour before surgery and Group ΙΙ patients receiving oral placebo. Post-op motor block and pain was assessed by using Bromage Scale and Visual Analogue Scale respectively. Statestical analysis used Both groups were compared by using paired t test. Results: the onset of sensory block in group II 4.40±0.11 min. Vs 3.58±0.10 min. in group I (p < 0.001) , the onset of motor block 5.47±0.12 min. in group II Vs 5.37±0.15 min. in group I (p < 0.001). the duration of sensory block in group II 154.8±13.01 min VS 211.1±10.37min. of group I duration of motor block 138.9±12.5 min. in group II VS 184.2±11.31 min. of group I. (p< 0.001). Total duration of Analgesia for group I 399.46 ± 6.12 vs 149.92 ± 4.14 for group I (P < 0.001). Conclusion: Clonidine as oral premedication hastens the onset of sensory block, motor block and increases duration of sensory and motor block as well as total duration of analgesia.