A Comparative Study of Intrathecal Clonidine Versus Intravenous Clonidine on Duration of Spinal Bupivacaine

Clonidine hydrochloride is an imidazoline derivative and exists as a mesomeric compound commonly used as an adjuvant to local anaesthesia as well as analgesia. Clonidine is a selective partial agonist for α-2 adrenoreceptors. The present clinical study aims at comparing the prolongation of spinal analgesia with intrathecal clonidine and intravenous clonidine. This study also aims at incidents of complications with intrathecal clonidine and intravenous clonidine. The clinical study was conducted on 100 patients at the Mahatma Gandhi Memorial Hospital, Warangal in between February 2008 to October 2008. In the present series various age groups of both sections undergoing lower abdomen and lower limb surgeries were selected for the study. The onset of sensory blockade was determined by applying pinprick for every 30sec interval after the completion of injection of the drug in CSF. The onset of analgesia in IT (intrathecal) group was 4.20 min ± 1.02, whereas, in the IV (intravenous) group was 4.53 ± 3.06 min. Intra and post operative complications in IT group the complications were hypotension 4%, bradycardia 2%. Whereas, IV group showed hypotension 6%, bradycardia 4%, sedation 2%, nausea and vomiting 4%. Post operative degree of pain relief was also studied in the present study by Magills classification. IT group showed 603± 5.3 min and IV group was 390.96±5.61 min. In conclusion, our study has demonstrated that addition of clonidine to bupivacaine in the dose of 1 μg.kg-1 significantly increases the duration of analgesia following its placement in subarachnoid space as compared to bupivacaine alone.