Comparison of oral clonidine and intrathecal fentanyl in spinal anesthesia with hyperbaric bupivacaine in lower limb elective surgeries

In recent years, by using adjuvant drugs to reduce the dose of local anesthetics and gaining faster recovery, while improving the quality of anesthesia and reducing the complications has been favored. This study was designed to compare the onset and duration of sensory and motor block, as well as the hemodynamic changes following administration of hyperbaric bupivacaine in spinal anesthesia supplemented with either intrathecal fentanyl or oral clonidine.

 In a double-blinded study, patients candidate for elective orthopedics surgery for leg were enrolled according to inclusion and exclusion criteria, and were randomized into two groups, each containing 30 patients. In fentanyl group, the patients received 3cc hyperbaric bupivacaine 0.5% and 25 μg fentanyl interathecally. In clonidine group, the patients received 0.1mg clonidine 60 minutes before beginning spinal block orally. Hemodynamic changes, sensory block by pinprick test and motor block by Bromage scale were measured and recorded by physician. There was no significant difference according to age, sex, mean arterial pressure and pulse rate (p>0.05). The level of sensory and motor blocks was higher in clonidine group than fentanyl group (p<0.002). There was no significant difference according to favorable sensory block for operation (p 0.147) or regression of sensory block (p=0.324). The regression time of motor block was less in clonidine group than fentanyl group (p=0.014). Administration of oral clonidine compare to intrathecal fentanyl to the hyperbaric bupivacaine in spinal anesthesia yields a higher sensory and motor block level and a faster regression time of motor block without producing any significant hemodynamic changes.