Introduction:–Spinal anesthesia–Regional anesthesia, is the most commonly used technique which provides a fast and effective onset of sensory and motor block, excellent muscle relaxation, and prolonged postoperative analgesia. In an attempt to further minimize the effects of local anesthetics and prolong the duration of intraoperative and postoperative analgesia, various adjuvants such as vasoconstrictors, alpha–2 agonists, and opioids have been used. Levobupivacaine is a preferred local anaesthetic due to its longer sensory block, lower cardiac and central nervous system toxicity and shorter motor block. Most commonly used opioid in regional anesthesia is fentanyl citrate which is a μ1 – and μ2 –receptor agonist.

In recent years alpha–2 agonist (Clonidine–commonly used as an adjuvant for postoperative analgesia.) are being extensively evaluated as an alternative to neuraxial opioids, as an adjuvants in regional anaesthesia. As neuraxial opioids may be associated with quite a few side effects, most important–respiratory depression. They can provide pain relief by an opioid independent mechanism. Therefore, the present study is being undertaken to evaluate and compare the effects of clonidine and fentanyl as intrathecal adjuvants to hyperbaric bupivacaine in patients undergoing lower limb orthopedic surgery.

            Material and methods:– The study was conducted in Department of Anesthesiology, Govt. Medical College, Kota from jan.2018 to dec.2018. with Due permission from institutional ethical committee was obtained. This is Hospital based Randomized double blind controlled observational study. This study included 80 Cases of either sex admitted for lower limb orthopedic surgeries. The  patients were randomly divided into 2 groups of 40 each.

Fentanyl Group (Group F) received 2 ml of 0.5% hyperbaric bupivacaine + .5ml of (25µg) of fentanyl  intrathecally. Clonidine Group (Group C) received 2 ml of 0.5% hyperbaric bupivacaine + .5 ml (30 µg) of clonidine (1:2.5 dilution) intrathecally. All data were collected and analysed with the help of suitable statistical parameters.

Results:– The mean duration of sensory block in group–Fentanyl was 199.6±7.3 min and in group–Clonidine was 275.7±11.3 min with a statistically highly significant difference (p–value 0.0001). The mean duration of motor block in group–Fentanyl was 151.7±8.6 min and in group–Clonidine was 225.7±12.7 min with a statistically highly significant difference (p–value 0.0001). In our study Modified Ramsay Sedation Score was significantly higher in group clonidine as compared to group fentanyl and the VAS chart for postoperative pain was significantly lower in group clonidine as compared to group fentanyl.