Dexmedetomidine with magnesium sulphate as adjuvants in caudal block to augment anaesthesia and analgesia in paediatric lower abdominal surgeries

Purpose
To investigate the implication of dexmedetomidine and magnesium sulphate addition to bupivacaine in caudal anesthesia in paediatric lower abdominal surgeries.
Study design
Randomized controlled trial.
Setting
Paediatric University Hospital.
Subjects
120 children undergoing surgeries in the lower half of the body under general anaesthesia with a supplementary caudal block using 1 ml/kg bupivacaine 0.25%.
Methods
Participants were randomly allocated into four groups; group C (saline as an additive to bupivacaine), group MG (50 mg magnesium sulphate added to bupivacaine), group D (1 µg/kg dexmedetomidine added to bupivacaine), and group MGD (the same doses of both dexmedetomidine and magnesium sulphate were added to bupivacaine). Time to first analgesia request (1ry outcome), and pain assessment by The Face, Legs, Activity, Cry, Consolability (FLACC) score just after recovery, then every 30 min in the early two hours, then at the 4th, 6th, 12th,18th, and 24th hours were compared between the groups.
Results
Time to first analgesia request was significantly longer in the three study groups compared to group C with p < 0.001 (median values of 5, 14.5, 13.5, and 20.47 h in groups C, D, MG, and MGD in consequence). FLACC scores were significantly higher in group C in comparison to the other study groups by the early 2nd, 4th, and 6th postoperative hours. The group MGD has significantly lowest FLACC at the 6th postoperative hour.
Conclusion
The combination of dexmedetomidine and magnesium sulphate with bupivacaine caudal block can prolong the time to first analgesia request.