Post-operative analgesic efficacy of 0.25% ropivacaine with dexmedetomidine versus dexamethasone as an adjuvant in bilateral superficial cervical plexus block for thyroidectomy under general anaesthesia-A comparative randomized clinical study

Abstract

Background and Aims: The bilateral superficial cervical plexus block (BSCPB) is efficacious for post-operative analgesia in thyroid surgeries. We assessed the analgesic efficacy of dexmedetomidine and dexamethasone administered as adjuvants with 0.25 percent ropivacaine in BSCPB for thyroidectomy under general anaesthesia with regard to the duration of analgesia, total amount of rescue analgesic requirement, changes in intra-and post-operative haemodynamic parameters, VAS scores, and adverse events, if any. Methods: A prospective double-blind trial was planned with 80 adults undergoing thyroidectomy, randomized into two equal groups and given BSCPB with 20 ml 0.25% ropivacaine with adjuvants as either dexmedetomidine 50μg (group A) or dexamethasone 4mg (group B), 10 ml on each side, after the induction of general anaesthesia. Post-operative pain was monitored using the visual analog scale and the duration of analgesia was measured by time to first rescue analgesia. Post-operative haemodynamics and any adverse events were recorded. Results: The mean duration of analgesia was slightly prolonged in group A but statistically non-significant as compared to group B (1037 ± 97 vs. 1004 ± 122 minutes; P0.18). The post-operative median VAS scores and vital parameters were relatively comparable for both groups (P > 0.05) for the first 24h. There was a significant reduction in the incidence of PONV (P < 0.05) in group B. Conclusion: Although dexamethasone offers a slight advantage of decreased incidence of PONV, BSCPB using ropivacaine with either dexmedetomidine or dexamethasone as an adjuvant imparted adequate analgesia with stable haemodynamics and may be used as a pre-emptive analgesic technique in thyroid surgeries.