Background: The task of medicine is to preserve, restore health and to relieve pain. Understanding pain is essential to both these goals. This present study was designed to know the motor and sensory blockade when clonidine with MgSO4 was added as an adjunct to bupivacaine

Objectives: To evaluate the Sensory Block: onset, duration, time for maximal sensory block and Motor Block: onset and duration of motor block

Methods: A prospective randomized controlled trial was done in patients posted for elective lower abdominal and lower limb surgeries for 2 years. Two groups were decided Group M (n=35), received 3 ml of 0.5% hyperbaric bupivacaine, preservative free magnesium sulphate 50%, 0.1 ml(50 mg) and preservative free normal saline 0.5 ml. Group CM (n=35), received 3 ml of 0.5% hyperbaric bupivacaine, preservative free magnesium sulphate 50%, 0.1 ml(50 mg) and clonidine 0.5ml (75µg). SPSS (version 22.0) was used for analysis.

Results: In group M, there were 17 males and 18 females, and in group CM there were 18males and 17 females. The onset of sensory block was faster in group CM compared to group M. By using unpaired t-tests, p-value was <0.0001.The onset of motor block was faster in group CM compared to group M. By using unpaired t- tests, p-value was <0.0001.

Conclusion: Based on the present clinical comparative study, we conclude that the combination of clonidine (75µg) and magnesium sulphate (50 mg) as adjuvants with hyperbaric bupivacaine 0.5% (15 mg) for subarachanoid blockade results in earlieronset of action, prolonged duration of sensory blockade and extended postoperative analgesia.

Keywords: Spinal Anaesthesia, Intrathecal Bupivacaine, Sensory blockade, Randomization, Bromage scale, post-operative analgesia.

1. Howard LF, Joseph BM. Pain-Pathophysiology and Management In Harrison‗s Principles of Internal Medicine, 15th Edition, Mc Grawhill, 2001.
2. Ronald DM editor. Miller‘s anesthesia. 7th ed. Churchill Livingstone; 2009; p3-54. 2767, 2758, 2760-7, 782-807, 1544, 1343, 2228
3. Vaswani RK, Raiger LK, Purohit R, Bajaj P. The effect of intrathecal midazolam on postoperative pain relief in orthopaedic surgery. Hospital Today2002;7(4):150-153.
4. Parameshwara G. Spinal, epidural to combined spinal epidural analgesia, thehistory of central neuraxial block. Indian J Anaesth 2001; 45(6):406- 412.
5. Dureja GP, Jayalaxmi TS. Colloid preloading before spinal and epidural anaesthesia. Hospital today 2000: V (11):601-603.
6. Buvanendran A, Mccarthy RJ, Kroin JS, et al. Intrathecal magnesium prolongsfentanyl analgesia: a prospective randomized controlled trial. Anesth Analgl,2002; 95:661-6.
7. Begon S, Pickering G, Eschalier A, Dubray C. Magnesium increase morphineanalgesia effect in different experimental models of pain. Anesthesiology,2002; 96:627-32
8. Sethi BS, Samuel M, Sreevastava D. Efficacy of Analgesic Effects of Low Dose Intrathecal Clonidine as Adjuvant to Bupivacaine. Indian Journal of Anaesthesia, 2007;51(5):415-419.
9. Bajwa SS, Bajwa SK, et al. Prevention of hypotension and prolongation of postoperative analgesia in emergency cesarean sections: A randomized study with intrathecal clonidine. Int J CritIllnInj Sci, 2012; 2(2): 63–69.
10. Gurudatta CL, Svenkatesh G et al. A Prospective randomized controlled study of the effect of intrathecal clonidine with hyperbaric bupivacaine 0.5% forlower abdominal surgeries. Karnataka Anesthesia J, 2008; 9(2).
11. Shukla D, Verma A, Agarwal A, Pandey HD, Tyagi C. Comparative study ofintrathecal dexmedetomidine with intrathecal magnesium sulfate used asadjuvants to bupivacaine. J Anaesth Clin Pharmacol, 2011;27:495-9.
12. Kothari N, Bogra J, Chaudhary AK. Evaluation of analgesic effects ofintrathecal clonidine along with bupivacaine in cesarean section. Saudi JAnaesth, 2011; 5(1): 31–35.
13. Malleeswaran S, Panda N, Mathew P, Bagga R. A randomised study ofmagnesium sulphate as an adjuvant to intrathecal bupivacaine in patients withmild preeclampsia undergoing caesarean section. International Journal of Obstetric Anesthesia, 2010; 19:161–166.
14. Fogarty DJ, Carabine UA, Milligan KR. Comparison of the analgesic effects of intrathecal clonidine and intrathecal morphine after spinal anaesthesia in patients undergoing total hip replacement. Br J Anaesth,1993;71:661-664.
15. Ozaleli M, Cetin TO, Unlugenc H, et al. The effect of adding intrathecal magnesium sulphate to bupivacaine-fentanyl spinal anesthesia. Acta Anesthesiol Scand, 2005; 49:1514-9.
16. Shashni S, Nair AS, Gopal T. Clinical effects of intrathecal midazolam versusintrathecal magnesium sulfate as adjuncts to hyperbaric bupivacaine: acomparative study. Indian j pain, 2013;27:175-81.

Dr Reji S Varghese

Associate Professor, Anesthesia, Pushpagiri Medical College and Hospital, Pathanamthitta Kerala