Background: Bilateral superficial cervical plexus block (BSCPB) is a frequently utilized regional anesthetic method for administering perioperative analgesia during thyroid operations. The use of adjuvants into local anesthetics such as bupivacaine can markedly enhance block quality and extend analgesia duration. Dexamethasone, a corticosteroid, and dexmedetomidine, an alpha-2 adrenergic agonist, are often utilized adjuvants with distinct processes and efficacy profiles. Aim: To compare the analgesic efficacy of dexamethasone and dexmedetomidine as adjuvants to bupivacaine in bilateral superficial cervical plexus block. Materials and Method: A prospective study was conducted on patients undergoing thyroid surgeries under general anaesthesia with BSCPB. Participants were divided into two groups: Group DEXA received 0.25% bupivacaine with dexamethasone (4 mg), and Group DEXM received 0.25% bupivacaine with dexmedetomidine (0.5 µg/kg). The primary outcome was the duration of postoperative analgesia. Secondary outcomes included onset time of sensory block, total analgesic consumption in the first 24 hours, pain scores at various time intervals, and incidence of side effects. Results: Group DEXM demonstrated significantly prolonged time to first rescue analgesia and required less intravenous paracetamol compared to Group DEXA (p < 0.001), indicating superior and longer-lasting analgesia. VAS scores were consistently lower in Group DEXM at 1, 2, 4, 6, and 12 hours postoperatively (p < 0.05), though differences were not significant at 24 hours. Sedation scores were higher in Group DEXM during the early postoperative period but all patients remained hemodynamically stable. There were no significant differences in intraoperative heart rate, blood pressure, or mean arterial pressure. Mild bradycardia and transient excessive sedation occurred in a few patients in Group DEXM but were easily managed. Conclusion: Both dexamethasone and dexmedetomidine effectively enhance the analgesic efficacy of bupivacaine in BSCPB for thyroid surgeries. However, dexmedetomidine provides a longer duration of analgesia and lower postoperative pain scores, albeit with increased sedation. It may be considered a superior adjuvant in patients where prolonged analgesia is desired.

Adjuvants, Bupivacaine, Dexamethasone, Dexmedetomidine, Thyroid Surgery.