Background: In elderly patients, use of adjuvant with small doses of local anesthetics is a preferred technique for spinal anesthesia for lower limb surgeries. This study tested the hypothesis that addition of small doses of clonidine augments the spinal block levels produced by hyperbaric bupivacaine in elderly without affecting the side-effects if any of clonidine in these patients.
Materials and methods: This was a prospective, randomized, double-blind study. Above 60 years male patients were allocated to three equal groups. Group C received 9 mg hyperbaric bupivacaine without clonidine while Group C15 and Group C30 received 15 μg and 30 μg clonidine with hyperbaric bupivacaine respectively for spinal anesthesia. Effect of clonidine on sensory block levels was the primary study outcome measure. Motor blockade and hemodynamic parameters were also studied.
Results: A significantly higher median block levels were achieved in Group C15 (P < 0.001) and Group C30 (P = 0.015) than Group C. Highest median sensory block level, the mean times for sensory regression to T12 level and motor block regression were statistically significant between Groups C15 and C and between Groups C30 and C. On comparison of fall in systolic blood pressure trends, there was no significant difference in the clonidine groups as compared with the control group.
Conclusions: In elderly patients, clonidine when used intrathecally in doses of 15 μg or 30 μg with bupivacaine, significantly potentiated the sensory block levels and duration of analgesia without affecting the trend of systolic blood pressure as compared to bupivacaine alone. Clonidine in doses of 30 μg however facilitated the ascent of sensory level block to unexpectedly higher dermatomes for a longer time.
Keywords: Clonidine; elderly; spinal anesthesia.