Comparative Study of Clonidine and Magnesium Sulfate Used as Adjuvant to Epidural Bupivacaine in Orthopedic Lower Limb Surgery.

ABSTRACT

Background: A lot of researches have been done to find an ideal adjuvant to bupivacaine in epidural anaesthesia that inhibits intra and post operative pain and prolongs the duration of anaesthesia without any side effects. Study regarding antinociceptive effect of magnesium in epidural route is very limited. Aim: This study was done to evaluate the onset, extent and duration of sensory and motor block and side effects of clonidine and magnesium sulfate when used as an adjuvant to bupivacaine in epidural anaesthesia in lower limb orthopedic surgery. Methods: A prospective randomized double blind study was conducted on 60 patients of American society of anaesthesiologists status I and II, posted for lower limb orthopedic surgery. All patients were randomly allocated into two groups of 30 each; group I was bupivacaine - clonidine group (BC) and group II was bupivacaine – magnesium sulfate group (BM). Group I (BC) patients received 16 ml of 0.5% bupivacaine and clonidine 2mcg/kg. Group II (BM) patients received 16 ml of 0.5% bupivacaine and magnesium sulfate (50 mg). The onset, extent, duration of sensory and motor blocks and side effects were recorded. Results: Magnesium sulfate had a visible edge over clonidine as it enabled an earlier onset of sensory block but duration of analgesia was more in clonidine group. Sedation scores were statistically significant with BC group in comparison to BM group. Both groups were haemodynamically stable in peri and post-operative period. Conclusion: Magnesium sulfate was a better alternative to clonidine as an adjuvant to bupivacaine in epidural anaesthesia in orthopedic lower limb surgeries for rapid onset of action but clonidine has prolonged duration of action.