Comparative study between perineural versus intravenous dexamethasone in prolonging the analgesic effect of supraclavicular plexus nerve block in upper limb surgeries

Background & Objectives: Dexamethasone is well known to potentiate the efficacy and the duration of local anesthetic drugs. The anesthetists have used this combination in spinal and epidural analgesia with satisfaction. We evaluated the efficacy of intravenous (IV) dexamethasone vs perineural administration in reducing postoperative pain in adults having supraclavicular brachial plexus blocks (BPB) for elective procedures involving the upper limbs. Methodology: This prospective randomized, double blind study involved 44 patients aged 18 to 60 y, both sexes, posted for elective upper limb cancer (synovial sarcoma, liposarcoma, melanoma, squamous cell carcinoma and osteosarcoma) surgeries under supraclavicular block, with an expected tourniquet time less than 120 min. Patients were divided into two equal groups: Perineural Dexamethasone group: 2 mL of dexamethasone (8 mg) combined with 28 mL of bupivacaine 0.25% concentration perineurally, along with 2 mL of normal saline as an IV placebo and systemic dexamethasone group: normal saline 2 mL was combined with 28 mL of bupivacaine 0.25% perineurally, and dexamethasone 2 mL (8 mg) was administered IV. Results: Onset time for sensory and motor block were significantly higher in systemic than perineural groups (P < 0.05). Duration of sensory blocks and duration of analgesia of the block were significantly lower in system than perineural groups (P < 0.05). There was significant difference between the two groups as regards the number of patients who needed a second dose of morphine (P = 0.030). Total morphine doses were significantly different between both groups. The duration of motor block was insignificantly different between both groups. Conclusions: When compared to its IV counterpart, perineural dexamethasone offers a prolonged duration of motor block, sensory block, and postoperative analgesia in ultrasound-guided supraclavicular brachial plexus block. Abbreviations: BPB: brachial plexus blocks, IV: intravenous, PACU: post-anesthesia care unit Keywords: Cancer; Perineural; Intravenous; Dexamethasone; Dysarthria; Pain; Supraclavicular Plexus Nerve Block; Upper Limb Surgeries; VAS Citation: Kamel MA, Abdelmonem AS, KamalGM, El Awady G, Soliman AM. Comparative study between perineural versus intravenous dexamethasone in prolonging the analgesic effect of supraclavicular plexus nerve block in upper limb surgeries. Anaesth. pain intensive care 2025;29(2):178-184. DOI: 10.35975/apic.v29i2.2701 Received: January 19, 2025; Reviewed: February 15, 2025; Accepted: February 15, 2025