Supraclavicular brachial plexus block using ropivacaine alone or combined with dexmedetomidine for upper limb...

Dexmedetomidine is a new α-2 receptor agonist with analgesic and sedative properties. We used dexmedetomidine along with ropivacaine for supraclavicular brachial plexus block.

Eighty ASA grade I-II patients, 18-60 years old, scheduled for elective upper limb orthopaedic surgery under supraclavicular brachial plexus block, were included in this prospective study. The patients were randomly assigned to group R (ropivacaine alone) and group RD (ropivacaine and dexmedetomidine) (40 patients in each group). Group R received ropivacaine 0.50% (30 cc)+placebo and group RD received ropivacaine 0.50% (30 cc)+dexmedetomidine 1 μg/kg. Primary outcome measure was duration of analgesia. Secondary measures were onset and duration of sensory blockade, pain scores, onset and duration of motor blockade, and evidence of any adverse drug reactions.

There was no significant difference hemodynamic parameter during intra-operative period. Group RD showed a statistically significant shorter time to onset of sensory blockade (10.75±2.71 vs. 16.75±2.96 min, P=.003), longer sensory block duration (379.40±55.09 vs. 211.60±47.88 min, P=.002), shorter onset time to motor blockade (14.35±2.58 vs. 20.25±4.13 min, P=.003), longer motor block duration (312.0±49.91 vs. 184.7±36.76 min, P=.002), longer duration of postoperative analgesia (413.73±89.92 vs. 197.35±28.67 min, P=.002). Three patients in the group RD developed somnolence. (P=.04).

Dexmedetomidine along with ropivacaine decreases the onset of motor and sensory block and increases the duration of sensory and motor block in supraclavicular brachial plexus block.