Background: Ultrasound-guided supraclavicular brachial plexus block (USSB) provides
excellent postoperative analgesia after upper extremity surgery. Dexamethasone and clonidine have
been added to local anesthetics to enhance and prolong the duration of analgesia.
Objective: The objective of this randomized prospective study is to evaluate the efficacy of dexamethasone,
clonidine, or combination of both as adjuvants to ropivacaine on the duration of USSB
for postoperative analgesia.
Methods: Patients receiving USSB for postoperative pain control for upper extremity surgery were
randomized to one of four groups; ropivacaine 0.5%, ropivacaine 0.5% with 4 mg dexamethasone,
ropivacaine 0.5% with 100 mcg clonidine , or ropivacaine 0.5% with 4 mg dexamethasone and 100
mcg clonidine. Pain scores, sensory and motor function were evaluated at post anesthesia care unit
(PACU), discharge and at 24 h postoperatively.
Results: The duration of sensory and motor blocks was significantly longer in clonidine groups
when compared to ropivacaine alone [Sensorial analgesia: ropivacaine alone 13.4±6, Ropivacaine-
Clonidine 17.4±6; Ropivacaine-Dexamethasone-Clonidine 18.8±6.2; Motor blocks: Ropivacaine
12±5, Ropivacaine-Clonidine 16.8±5.2, Ropivacaine-Dexamethasone-Clonidine 18.2±5.7]. In
clonidine groups, there was significant prolongation of motor and sensory block when compared to
ropivacaine group alone.
Conclusion: The results demonstrated that clonidine significantly prolongs the duration of ropivacaine
effects for the postoperative analgesia in patient underwent upper arm surgeries.