Effects of Low Dose Dexamethasone as an Adjuvant to Levobupivacaine in Ultrasoundguided Interscalene Brachial Plexus Block: A Randomised Clinical Trial

Abstract

Introduction: Ultrasound-guided Interscalene Brachial (USGISB) plexus block is known to provide effective analgesia for upper limbs surgery. Low-dose dexamethasone as additive with levobupivacaine in USG-ISB plexus block is known to provide effective analgesia for upper limbs surgery. Aim: To evaluate whether dexamethasone, use as an additive with levobupivacaine during an USG-ISB plexus block for upper limb surgery, has sufficient analgesic effect. Materials and Methods: The randomised clinical trial was conducted at GGS Medical College and Hospital, Faridkot, Punjab, India, from March 2018 to August 2019. Sixty patients who were scheduled to have upper limb surgery using USG-ISB with 0.5% levobupivacaine were randomly assigned to one of two groups. Group A (n=30) received one ml of normal saline, while group B (n=30) received 4 mg of dexamethasone. A fourpoint Verbal Numerical Rating Scale (VNRS) for pain was used to evaluate postoperative analgesia. The duration of analgesia, time to onset and duration of sensory and motor blockade, and pain ratings were measured. Unpaired student's t-test, Chisquare and Fisher’s-exact tests were used to analyse the data. Results: The mean duration of analgesia was significantly longer for group B than for group A (854.67±10.08 min vs 743.00±23.22 min; p-value<0.001). The onset of sensory and motor blocks in group B began to develop earlier (8.42±0.35 min, and 9.72±0.55 min) than those in group A (10.10±0.80 min, and 11.02±0.84 min; p-value<0.001). The duration of the sensory and motor block in group B was longer (653±16.17 min and 582.83±14.18 min) than that in group A (595±17.29 min and 487.33±21.04 min; p-value<0.001). Conclusion: Perineural dexamethasone with levobupivacaine provides greater postoperative analgesia, also speed up the onset of sensory and motor effects, and prolongs the duration of interscalene brachial plexus block.