Use of subarachnoid block (intrathecal) has become an established and reliable method of providing anesthesia for orthopedic lower limb surgery.

 Aim: To compare intrathecal low dose clonidine – hyperbaric bupivacaine 0.5% combination with hyperbaric bupivacaine 0.5% in respect to hemodynamic response, analgesia duration and side effects in orthopedic lower limb surgeries.

Material and Methods: 90 patients enrolled in this study were randomly divided in  3 group of 30 each. Group I – received  only 3ml 0.5% hyperbaric bupivacaine  (15 mg) intrathecally while Group II & III– received 25µg and 50 µg Clonidine as adjuvant to 3 ml 0.5% hyperbaric bupivacaine  respectively.

Results: The duration of anaesthesia i.e: regression of sensory level below L1, duration of analgesia and sedation score was maximum (clinically significant) in group III followed by group II  then group I. The incidence of side effects like bradycardia , hypotention , sedation & nausea /vomiting were more in Group III followed by group II then group I.

Conclusion: clonidine as   an  adjuvant  to    bupivacaine  significantly  increase  the  duration of anesthesia  and  post  – operative  analgesia.  In  view  of  sedative  effect  of  50 µg  clonidine  it should be used judiciously in ASA class>II patient.