Radha Korumbil Raghavan 1 , Shiril Ashraf
BACKGROUND The aim of this study was to evaluate the effects of dexamethasone and magnesium sulfate as additives to local anaesthetic solution containing lignocaine and bupivacaine in supraclavicular brachial plexus block. MATERIALS AND METHODS A prospective randomised double blind control study was conducted on 90 healthy patients of ASA grade I, II of age group 18-50 years scheduled for upper limb surgeries under supraclavicular block. Patients were allocated to three groups of 30 each as a control group (S) received only local anaesthetic, group getting dexamethasone as additive (SD) and group getting magnesium sulfate as additive to local anaesthetics (SM).Parameters observed were time of onset of sensory and motor block, duration of analgesia and side effects. RESULTS Onset of sensory block was most rapid in Group SD and was statistically significant when compared to Group S (p<0.01) and Group SM (p<0.01). The meantime for sensory block onset was 11.07 ± 2.033 mins in Group S, 6.80 ± 2.384 minutes in Group SD and 8.70± 1.896 minutes in Group SM. Mean time for onset of motor block in Group S, Group SM, and Group SD was 13.17± 2.66 minutes, 10.27± 2.39 minutes and 9.40 ± 2.29 mins respectively. Onset of motor block was earliest in Group SD and this was statistically significant when compared to Group S (p<0.01) but statistically insignificant (p=0.526) between Group SD and Group SM. Duration of analgesia was found to be highest in Group SD with mean duration of analgesia (738.33 ± 187.69 minutes) and in Group S it was (308.33 ± 60.05 minutes) and Group SM was 628.02 ± 182.06 minutes. It was statistically significant when compared to Group S (p<0.01) and Group SM (p<0.01). CONCLUSION It is concluded from this study that both magnesium sulfate and dexamethasone prolong the duration of analgesia, when used with local anaesthetic solution containing lignocaine and bupivacaine for supraclavicular brachial plexus block, without producing any major side effects. Dexamethasone is a better adjuvant than magnesium sulfate because, in addition to prolonging the duration of analgesia, it also results in more rapid onset of sensory and motor blockade.
