Perineural versus Intravenous Dexmedetomidine for Ultrasound-guided Costoclavicular Brachial Plexus Block: A...

Dexmedetomidine is a sought-after adjunct to prolong the effects of local anesthetics in regional anesthesia, administered through both perineural and intravenous (IV) routes. However, there is still an ongoing debate to ascertain the preferred route of administration. We conducted this trial because there is a lack of literature about the comparative advantages of these approaches in costoclavicular brachial plexus block (CC-BPB).

Sixty subjects were randomized to Group A (received 0.5 μg/kg dexmedetomidine plus 20 mL of 0.5% ropivacaine administered perineurally, preceded by 50 mL of normal saline [NS] infused intravenously over 10 min) and Group B (received 20 ml of 0.5% ropivacaine perineurally, preceded by IV infusion of dexmedetomidine 0.5 μg/kg in 50 ml NS over 10 min). The block characteristics, pain scores, sedation scores, and adverse events were analyzed using pertinent statistical tests.

Group A exhibited a notably quicker onset of sensory block (5.43 ± 3.02 min) versus (7.77 ± 2.14 min) in Group B (P = 0.0011, Cohen's d = -0.89). Group A had a quicker onset of motor block (9.27 ± 4.18 min) versus (13.83 ± 3.80 min) in Group B (P < 0.0001, Cohen's d = -1.14). In addition, Group A had significantly longer durations for sensory block (928.9 ± 121.0 min) versus (679.6 ± 84.58 min) (P < 0.0001, Cohen's d = 2.39), motor block (868.6 ± 117.5 min) versus (623.2 ± 87.73 min) (P < 0.0001, Cohen's d = 2.37), and duration of analgesia (955.8 ± 121.6 min) versus (705.0 ± 86.23 min) (P < 0.0001, Cohen's d = 2.3).

As an adjunct to ropivacaine in CC-BPB, perineural dexmedetomidine offers quicker onset and extended duration of anesthesia and analgesia than the IV route with a comparable hemodynamic profile.