Effect of Perineural Dexmedetomidine on the ED50 Ropivacaine for Brachial Plexus Blocks in Pediatric Patients: a Randomized Trial

Dexmedetomidine can prolong the duration of local anesthetics, but the effect of perineural dexmedetomidine on the potency of ropivacaine for brachial plexus blocks in pediatric patients has not been investigated. This study was designed to determine the effect of perineural dexmedetomidine on ropivacaine for brachial plexus blocks in pediatric patients

150 children scheduled for arm and forearm surgery underwent supraclavicle brachial plexus blocks with ropivacaine guided by ultrasound visualisation were randomly assigned to one of the five groups: Group A (perineural ropivacaine), Group B (ropivacaine plus 0.5 mcg/kg dexmedetomidine), Group C (ropivacaine plus 1 mcg/kg dexmedetomidine), Group D (ropivacaine plus 1.5mcg/kg dexmedetomidine) and Group E (ropivacaine plus 2 mcg/kg dexmedetomidine). The primary endpoint was the minimum local anesthetic concentration (MLAC), which was determined using the Dixon up-and-down method. The secondary endpoints were the duration of analgesia and sedation

Inclusion Criteria:

• ASA I,II children, aged between 2 and 6 years, who were scheduled for arm and forearm surgery underwent supraclavicular brachial plexus blocks.

Exclusion Criteria:

• any subjects with neurological, neuromuscular, psychiatric, or blood clotting disorders, or known history of active and severe renal, hepatic, respiratory, or cardiac diseases, or known allergy to systemic or local anesthetics or dexmedetomidine