A randomized placebo-controlled trial to assess the efficacy and safety of bilateral superficial cervical plexus block in patients undergoing thyroid surgery

Background: Efficient analgesia and achieving hemodynamic stability is vital in patients undergoing thyroid surgery. Bilateral superficial cervical plexus block (BSCPB) is one of the commonly performed regional anaesthesia technique, but studies documenting the superiority of various local anaesthetic medication, as compared to placebo are scarce. To compare the efficacy of analgesia, intra and post-operative hemodynamic status between bilateral superficial cervical plexus block with 0.5% bupivacaine and a control group (normal saline) in thyroid surgeries. Materials and methods: The current study was a randomized double-blinded controlled trial conducted with prior ethical approval. The study population included, people undergoing thyroid surgery under general anaesthesia, randomized to either 0.5% Bupivacaine or normal saline groups. The post-operative pain was assessed by Visual Analogue Scale (VAS). The intra and postoperative hemodynamic parameters were compared. Unpaired t-test, Mann-Whitney U test was used appropriately. Results: A total of 58 patients included in the final analysis, with 29 subjects in each group. Both the study groups were comparable, with respect to various baseline parameters. The highest difference in the mean visual analogue score was observed in the immediate post-operative period (mean difference 4.03, 95 CI 3.4 to 4.66, p value < 0.001). This difference even though was variable and lower compared to the immediate post-operative value, was sustained throughout the post-operative period. At 24 hours, post-operative period the mean difference in visual analogue score was 1.55 (95% CI 0.93 to 2.16, p value < 0.001). All these differences in the mean visual analogue scores were statistically significant at p value < 0.05. No major hemodynamic fluctuations were observed in either of the study groups and no statistically significant difference was observed with respect to various hemodynamic parameters. Conclusions: The data and statistical analysis suggest that Bilateral Superficial Cervical Plexus Block with bupivacaine did not alter the intraoperative hemodynamic parameters and was effective in reducing the pain during the postoperative period. No significant adverse effects were noted both during surgery and postoperative period.