The motor effects of 0.25% bupivacaine vs 0.19 bupivacaine in ultrasound-guided axillary brachial plexus block in pediatrics undergoing below-elbow orthopedic surgeries: A randomized controlled study

Background
The standard dose of bupivacaine used in axillary brachial plexus block (ABPB) in pediatrics is 0.5 ml/kg of bupivacaine 0.25%. However, bupivacaine (0.19%) is still to be investigated for peripheral nerve block in pediatrics regarding the efficacy and adequacy of intra- and postoperative analgesia and degree of motor affection. We aimed to compare different concentrations (0.25%, 0.19%) of bupivacaine plus dexmedetomidine mixture to perform US-ABPB in pediatrics undergoing upper limb surgery distal to the elbow regarding affecting the postoperative motor power and adequacy of intra- and postoperative analgesia.
Methods
This prospective, randomised-controlled, double-blinded work was performed on 60 pediatric individuals presenting for upper limb orthopedic surgeries in the wrist, hand, and elbow distal to cubital fossa with surgical time planned to not exceed 1 h. 0.25% bupivacaine plus 1 µg/kg dexmedetomidine (Group A) or 0.19% bupivacaine in addition to 1 µg/kg dexmedetomidine (Group B) were given at random to participants. Motor power and pain were assessed using the Modified Bromage scale, Face, Legs, Activity, Cry, and Consolability (FLACC) score, respectively.
Results
A highly substantial variation was recorded between the two groups in Bromage 0 till Bromage 60 with higher values in group (B), and no substantial variation was found in Bromage 90 till Bromage 180 existed between the two groups. No substantial variation existed among the two groups with regard to FLACC score in FLACC0 (immediately after recovery), 1 hour after recovery, and 12 hour after recovery, and FLACC was significantly more ( < 0.05) in group B contrasted to group A in the 4 hour after recovery and 8 hour after recovery.
Conclusion
Using a lower concentration of bupivacaine (0.19%) plus dexmedetomidine (1 µg/kg) was associated with regain of postoperative motor power with the same postoperative analgesic efficacy compared to the standard concentration (0.25%) bupivacaine plus dexmedetomidine (1 µg/kg) in the early postoperative period in US-ABPB.