Background & Objectives: comparing the effect of adding dexamethasone and magnesium sulfate to bupivacaine in ultrasound guided supraclavicular brachial plexus blockade. The primary endpoints were the onset of sensory and motor block and quality of analgesia and the secondery end points were duration of analgesia and motor block.
Materials & Methods: Ninety patients scheduled for elective surgeries on the upper limb under ultrasound guided supraclavicular brachial approach. patients were randomly allocated using a standard randomization code, in a double blinded manner, into three groups; group one (n=30) received 20 ml 0.5% plain bupivacaine, group two (n=30) received 18 ml bupivacaine 0.5% + 2 ml (8mg) dexamethasone, group three (n=30) received 18 ml bupivacaine 0.5% + 200 mg magnesium sulfate.
The following parameters were studied: Onset of sensory block, onset of Motor blockade, haemodynamic and respiratory data, Analgesia time,and Duration of motor and sesory blocks
Results: There was no significant difference in the demographic data and surgical characteristics in the three groups. The sensory block onset time in minutes was earlier in group 2 (dexamethasone) as compared to group 1 and 3; 8.20±2.09 versus 16±3.48 (P< 0.05) and 8.20±2.09 versus 12.70 ± 2.92(P< 0.05) respectively, also the sensory block onset was earlier in group 3 (magnesium) than group 1 (control) 12.70 ± 2.92 versus 16±3.48 (P< 0.05). Also onset of motor blockade in minutes was earlier in group 2 than in group 1 and 3; 1.50 ± 2.09 versus 13.10 ± 3.34 (p< 0.05) and 12.75 ± 3.43 respectively, while the difference in motor block onset was clinically insignificant between group 1 and 3(P> 0.05). As regard duration of analgesia in minutes it was significantly longer in group 2 than group 1 and 3 1104.00 ± 289.16 versus 313.50 ± 103.68 and 558.00 ± 48.08 respectively, also analgesia duration was significantly prolonged in group 3 than group 1(P< 0.05). the motor power was significantly prolonged for group 2 than group 1 and 3; 563.00 ± 69.29 versus 136.50 ± 28.34 and 214.50 ± 36.92 respectively, and also the motor power return was delayed in group 3 than group 1(P< 0.05).
Conclusion: both of them proved to prolong the duration of block and the analgesia time, both of them fasten the sensory block onset time, but dexamethasone is significantly more effective in prolonging the analgesia duration and the block duration. dexamethasone shorten the motor block onset time while magnesium does not enhance the motor block onset time.
