Introduction: Prolongation of analgesia after single shot Brachial Plexus Block (BPB) with local anesthetic remains a challenge. Dexamethasone prolongs duration of action of local anesthetic when used as an adjuvant. We aimed to determine the efficacy of dexamethasone after addition to bupivacaine for prolongation of analgesia & motor block in BPB.

Methods: A prospective, randomized, double blind study was carried out in a tertiary care hospital during the period of May 2016 to January 2019. Patients (n = 50) between 18 and 70 years of age of either sex undergoing upper limb surgery were enrolled. Patients in Group Ι (n = 25) received 0.5% bupivacaine plus dexamethasone 8 mg and Patients in Group ΙI (n = 25) received 0.5% bupivacaine plus 0.9% normal saline. Mean duration of analgesia, mean duration of motor block, onset of sensory block & onset of motor block were recorded. ‘p’ value less than 0.05 was taken as significant.

Results: Demographic characteristics were comparable in both the study groups. The mean duration of analgesia was significantly longer in Group Ι as compared to Group II (748.5 ± 65.57 mins vs 555.4 ± 35.20 mins: p < 0.05). Group Ι showed significantly longer mean duration of motor block compared to Group II (814.3 ± 100.81 mins vs 690.3 ± 81.36 mins: p < 0.05). Similarly, the onset of motor block was significantly rapid in Group Ι as compared to Group II (13.04 ± 2.09 mins vs 14.52 ± 2.29 mins: p < 0.05).

Conclusion: Dexamethasone as an adjuvant to bupivacaine in brachial plexus block significantly prolongs the duration of analgesia and motor block in patients undergoing upper limb surgery.